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STUDY PROTOCOL
Emotion regulation in children (ERiC): A
protocol for a randomised clinical trial to
evaluate the clinical and cost effectiveness of
Mentalization Based Treatment (MBT) vs
Treatment as Usual for school-age children
with mixed emotional and behavioural
difficulties
Nick MidgleyID
1,2
*, Rose Mortimer
1,2
, Mark Carter
3
, Polly CaseyID
1,2
, Lisa Coffman
4
,
Julian Edbrooke-Childs
1,2
, Chloe Edridge
1,2
, Peter Fonagy
1,2
, Manuel Gomes
2
,
Anoushka Kapoor
1,2
, Susannah Marks
5
, Peter MartinID
2
, Bettina Moltrecht
1,2
,
Emma Morris
1,2
, Nikola Pokorna
1,2
, Tara McFarquharID
1,2,6
1The Anna Freud Centre, London, United Kingdom, 2University College London, United Kingdom,
3Barnet, Enfield and Haringey NHS Trust, United Kingdom, 4Barnet Parent/Carer Forum, United Kingdom,
5Oxford Health NHS Foundation Trust, United Kingdom, 6University of East Anglia, Norwich, United
Kingdom
*nicholas.midgley@ucl.ac.uk
Abstract
Background
The majority of children referred to Child and Adolescent Mental Health Services (CAMHS)
in the UK will present with mixed emotional and behavioural difficulties, but most mental
health treatments are developed for single disorders. There is a need for research on treat-
ments that are helpful for these mixed difficulties, especially for school-age children. Emo-
tion Regulation (ER) difficulties present across a wide range of mental health disorders and
mentalizing may help with regulation. The ability to mentalize one’s own experiences and
those of others plays a key role in coping with stress, regulation of emotions, and the forma-
tion of stable relationships. Mentalization Based Therapy (MBT) is a well-evidenced therapy
that aims to promote mentalization, which in turn increases ER capacities, leading to
decreased emotional and behavioural difficulties. The aim of this study is to test the clinical-
and cost-effectiveness of MBT compared to treatment as usual for school age children with
emotional and behavioural difficulties. If effective, we hope this approach can become avail-
able to the growing number of children presenting to mental health services with a mix of
emotional and behavioural difficulties.
Materials and methods
Children referred to CAMHS aged 6–12 with mixed mental health problems (emotional and
behavioural) as primary problem can take part with their parent/carers. Children will be
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Citation: Midgley N, Mortimer R, Carter M, Casey
P, Coffman L, Edbrooke-Childs J, et al. (2023)
Emotion regulation in children (ERiC): A protocol
for a randomised clinical trial to evaluate the clinical
and cost effectiveness of Mentalization Based
Treatment (MBT) vs Treatment as Usual for
school-age children with mixed emotional and
behavioural difficulties. PLoS ONE 18(8):
e0289503. https://doi.org/10.1371/journal.
pone.0289503
Editor: Vanessa Carels, PLoS ONE, UNITED
STATES
Received: July 10, 2023
Accepted: July 17, 2023
Published: August 17, 2023
Peer Review History: PLOS recognizes the
benefits of transparency in the peer review
process; therefore, we enable the publication of
all of the content of peer review and author
responses alongside final, published articles. The
editorial history of this article is available here:
https://doi.org/10.1371/journal.pone.0289503
Copyright: ©2023 Midgley et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
randomly allocated to receive either MBT or treatment as usual (TAU) within the CAMHS
clinic they have been referred to. MBT will be 6–8 sessions offered fortnightly and can flexi-
bly include different family members. TAU is likely to include CBT, parenting groups, and/or
children’s social skills groups. Parent/carers and children will be asked to complete outcome
assessments (questionnaires and tasks) online at the start of treatment, mid treatment (8
weeks), end of treatment (16 weeks) and at follow up (40 weeks).
Trial registration
Clinical trial registration: ISRCTN 11620914.
Introduction
In 2021, one in six (16.0%) children in England aged 5 to 16 were identified as having a proba-
ble mental disorder [1]. The majority of these children, when presenting to child mental health
services, do not receive an evidence-based treatment. This is partly because most empirically
tested treatments were developed to treat single disorders [2,3], whereas the evidence indicates
that the structure of mental health symptoms does not straightforwardly map onto traditional
diagnostic categories and comorbidity of mental health problems is high [4,5]. Indeed, most
children referred for treatment show high rates of transdiagnostic co-morbidity–this is the
rule, not the exception [6]. As a result, there is a significant research-practice gap.
A solution to this research-practice gap is for clinical trials to focus on transdiagnostic inter-
ventions that target causal and maintaining factors underlying a range of clinical presentations.
Transdiagnostic interventions are especially suitable for children, who show a great overlap in
symptoms and a high level of transitory symptoms across developmental stages [7–9]. Trans-
diagnostic interventions also have good potential for implementation, as they allow clinicians
to address diverse diagnoses and sub-threshold symptoms within a single treatment model,
and simultaneously target multiple problem areas, so limiting training burden on clinicians
[9–11].
Because of the ubiquity of emotion regulation (ER) difficulties across a wide range of psy-
chopathologies, research has identified ER as a core transdiagnostic mechanism [12]. ER refers
to implicit and explicit processes and strategies involved in regulating emotional states. Both
adequate down-regulation of negative emotional states and up-regulation of positive states
during childhood play a critical role in adaptive development and well-being [13]. ER difficul-
ties have been associated with risk of psychopathology across both emotional and behavioural
disorders [14–16]. Findings of a recent meta-analysis suggest that interventions can enhance
ER in youth, and that these changes correlate with improvements in psychopathology [17].
However, of the 21 studies in the meta-analysis, only 4 targeted children aged 6–12, thereby
highlighting a significant evidence gap for this age group. In addition, most research and inter-
ventions have neglected the role of positive/adaptive ER strategies, despite recent research
highlighting their importance, especially for children and young people [17].
The capacity to ‘mentalize’ is now recognised as a key component of positive or adaptive
ER [18]. Mentalizing has been defined as ‘the process by which we make sense of each other
and ourselves, implicitly and explicitly, in terms of subjective states and mental processes’ [19]
(p. 11). The ability to mentalize one’s own experiences and those of others plays a key role in
coping with stress, regulation of emotions, and the formation of stable relationships [18].
Empirical studies have shown that deficits in the capacity to mentalize are predictive of mal-
adaptive ER in both clinical and non-clinical populations [20,21], and that there are deficits in
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Data Availability Statement: Deidentified
quantitative research data will be made publicly
available when the study is completed and
published.
Funding: - NM, PM, BM, MG, JEC, MC, SM, EM,
PF and LC received the grant award for this project
- Grant number: Kavli2021-0000000090 - Funder
name: The Kavli Trust - Funder website: https://
kavlifondet.no/en/ - The funders did not and will not
have a role in study design, data collection and
analysis, decision to publish, or preparation of the
manuscript.
Competing interests: The authors have declared
that no competing interests exist.
mentalizing capacity among children with either internalizing or externalizing psychopathol-
ogy [22–25].
The importance of parental mentalizing to the well-being of children is also clearly estab-
lished. Parental mentalizing has been found to be significantly associated with both child’s
internalizing and externalizing symptoms and social–emotional competencies [26]. The qual-
ity of a carer’s mentalizing is positively associated with sensitive caregiving, strengthened par-
ent-child relationships, and secure attachment [27,28]. Parents with higher mentalizing
capacity are better able to tolerate emotional distress in their children, which is thought to be
helpful in managing parenting stress [29]. A systematic review exploring the association
between parental mentalizing and children’s mental health outcomes [30] highlighted that
poor maternal mentalization is associated with overcontrolling parenting [31], a higher inci-
dence of child anxiety [32], child emotion regulation difficulties [33] and greater child exter-
nalizing behaviours [34].
Mentalization Based Treatment (MBT) was originally developed as a treatment for adults with
a diagnosis of borderline personality disorder [19], where emotion dysregulation is a key feature.
The evidence base for its effectiveness with this group is good [35]. More recently it has been
adapted for therapeutic work with children and families [36]. For school age children, there is pre-
liminary evidence that promoting a child’s mentalizing capacity can improve ER and symptom-
atic improvement, including children’s behavioural and emotional difficulties [24,37]. Moreover,
improvement in parents’ capacity for mentalizing has been associated with reductions in chil-
dren’s internalizing and externalizing problems [38]. However, as a recent systematic review has
highlighted, high quality clinical trials of MBT for school-age children are lacking [39], and time-
limited MBT has yet to be evaluated as a transdiagnostic intervention for school-age children.
In summary, given that many children presenting to mental health services experience
comorbid difficulties, there is a need for evidence-based transdiagnostic interventions that
effectively target mechanisms underlying co-occurring mental health difficulties; ER is the
best-evidenced mechanism implicated in a range of common mental health disorders. MBT is
a well-evidenced therapy for a range of populations that aims to promote mentalization, which
in turn increases ER capacities, leading to decreased emotional and behavioural difficulties.
Until now, children under 12 have not had the benefit of this transdiagnostic approach, as the
evidence for its effectiveness in this population has not yet been examined. The aim of this
study is to test the clinical- and cost-effectiveness of MBT against treatment as usual (TAU) for
school-age children with comorbid internalizing and externalizing difficulties. We will con-
duct the first randomised controlled trial of MBT for this population and examine the role of
ER as a mediator of treatment response. Our hypotheses are as follows:
Hypothesis 1: Children allocated to MBT will experience a significantly greater reduction in
mental health problems–both internalizing and externalizing–when compared with the
TAU group.
Hypothesis 2: Families allocated to MBT will also experience a greater improvement in a range
of secondary outcomes, including improved capacity for emotion regulation, and decreased
parental stress, and a reduction in health and social service use and costs compared to the
TAU group.
Hypothesis 3: The impact of treatment on child mental health will be mediated, in part, by
changes in capacity for emotion regulation (in both parent and child).
The Implementation and Process Evaluation (IPE) aims to investigate: a) model fidelity, b)
the experience of MBT (including the change process) from the perspective of service users;
and c) any barriers to implementation and scalability post-trial.
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If effective, we hope this scalable, transdiagnostic approach can become available to the
growing number of children presenting to mental health services with a mix of internalizing
and externalizing difficulties. In addition, it may enable a more efficient allocation of health
and social care resources by reducing the need for longer-term, more intensive specialist men-
tal health interventions.
Materials and methods
Trial design
This study will be a pragmatic, individually randomized, superiority trial comparing MBT
with TAU, with those administering outcome measures and analysing the data, blind to group
assignment. An internal pilot will inform the optimal delivery of the main study, which will be
a fully powered, randomised control trial of the intervention. Both the internal pilot and main
trial will have an embedded qualitative component. Assessments of capacity for ER will enable
mediator analyses to identify mechanisms underlying symptom change.
The internal pilot will take place before the main RCT, across two NHS Trusts, following
the same recruitment and data collection procedures as the main trial. The internal pilot will
be an opportunity to test a) the process and procedures of training and supervising the practi-
tioners delivering MBT; b) the recruitment processes (including screening of referrals and
contact with families); and c) the feasibility of data collection processes. With regard to this
third aim, this will include feasibility of remotely conducting two task-based assessments of
emotion regulation. Recent recommendations for the assessment of emotion regulation pro-
cesses suggest that researchers adopt a multi-modal approach, where self-report measures are
complemented with task-based and/or observational measures, although few studies have
done this sufficiently especially as part of clinical trials [17]. Hence, one of our objectives for
the internal pilot phase is to explore the feasibility of our multi-modal assessment approach as
part of a clinical trial and test the convergence validity of the different ER measures. If success-
ful, we will carry forward self-report and one or both task-based ER measures to the main trial
where they may be employed at baseline only.
Study setting
The study will be set in two large mental health trusts in the UK: Barnet, Enfield and Haringey
(BEH) Mental Health NHS Trust and Oxford Health NHS Trust, which between them run 12
child and adolescent mental health services (CAMHS). Involvement with the study is sup-
ported at senior management level within these CAMHS. These services receive over 3,000
referrals of children aged 6–12 per year, from a diverse cultural and social background. The
services are multi-disciplinary, including clinical psychologists, child psychiatrists, child psy-
chotherapists, family therapists, social workers, primary mental health workers and clinical
nurses.
Participants
320 children aged 6–12 with mixed (internalizing and externalizing) mental health problems,
and their parents/carers. Children will be recruited from referrals to participating CAMH
services.
Based on data available from services, approximately 60% of referrals are accepted as suit-
able for CAMHS, and a case file review has indicated that approximately 40% of accepted cases
are likely to meet our inclusion criteria, with the majority of other referrals in this age group
related to Autistic Spectrum Disorder (ASD) or neurodevelopmental disorders. This would
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make an estimated eligible pool of 720 children per year. We anticipate a consent rate of
approximately 40–50%. The number of children included in each participating CAMHS team
will be monitored by the trial team throughout the recruitment phase of the study. If the intake
of children falls behind recruitment targets, appropriate action will be taken, including the
possibility of adding additional clinical sites to the study.
During the internal pilot we will aim to recruit 40 families to the study (20 to MBT, 20 to
Treatment as Usual). The research team will monitor recruitment during the pilot phase in
order to identify any barriers to recruitment and to allow for any changes in procedure.
Eligibility criteria
Inclusion criteria. Child aged 6–12; carer-reported Strengths and Difficulties Question-
naire (SDQ) total difficulties score for child of �14 with emotional problems �5 and conduct
score �3; combined with a functional impairment score of �1.
Exclusion criteria. Current participation in another mental health intervention trial. A
pre-existing clinical diagnosis (in child or parent) of: psychotic disorder, ASD, pervasive devel-
opmental disorder, eating disorder, severe learning difficulty, or (in parent) severe substance
abuse disorder. Children will also be excluded where the referring clinician identifies an imme-
diate risk of harm to self or others.
Recruitment, screening and gaining informed consent
The study began recruitment in April 2023 and will recruit participants over a 16-month
period (4 months for the internal pilot, and 12 months for the main trial), with the pilot sites
continuing to recruit while data from the internal pilot is analysed and sites are set up for the
main trial. A SPIRIT schedule of enrolment, interventions, and assessments is presented in Fig
1, and participants’ journey through the trial is mapped out in Fig 2, and specific aspects are
explained in more detail below.
All new referrals will be initially screened by a member of the CAMHS intake team to see if
the child will be aged 6–12 by the time of randomisation and that there are no indications that
any exclusion criteria apply. The parents/carers of those children who may be eligible will be
offered further information about the study; consent will be sought from the family to pass the
parent’s contact details to the research team. The research team will then send information
sheets by email to those parents/carers who have agreed to share their contact details, along
with a link to a screening questionnaire. If the screening questionnaire indicates that the child
is eligible, the research team will offer a telephone/video call to discuss the study further and
answer any questions the parent/carer may have. If the family is interested in the study, the
parent/carer will be sent a link to the eConsent form. Children will be invited to provide eAs-
sent to participate at study entry, and verbal assent will be sought by researchers prior to com-
mencing optional interviews and tasks.
Once informed consent has been granted, the parent/carer will be able to access and com-
plete the parent/carer and child baseline questionnaires online. At the family’s request, all mea-
sures can also be completed on a call with the research team while accessing a blank PDF
version of the questionnaires. A video call with the family will be arranged for completion of
the Test of Emotional Comprehension (TEC) task and parent-child interaction task, if agreed
to in eConsent form.
Randomization
Once mandatory elements of baseline data collection have been completed, participants will be
randomized to either MBT or TAU, stratified by CAMH service and age group (6–9 years and
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Fig 1. SPIRIT schedule of enrolment, interventions, and assessments.
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10–12 years old), using permuted blocks of size 2 within each stratum. The randomization
sequence will be generated from random numbers generated in the R software for statistical
computing [40] and pre-loaded into the REDCap data management platform, which will be
used for data collection.
The randomization sequence will be stored but concealed within the REDCap data capture
system. When all information relevant for stratification (CAMH service and age) has been
completed, a researcher has the option to initialize randomization. Only then will the alloca-
tion be revealed within the REDCap database, and the CAMH service will be informed of the
result of the randomization, so that treatment can be initiated.
Interventions
Interventions in both arms of the study will be delivered by therapists working in the CAMHS
teams taking part in the study. As part of study set up, all therapists taking part in the study
will be randomly selected to either deliver MBT or treatment as usual. Therapists will be strati-
fied by NHS banding, which takes into consideration profession and level of experience, to
ensure that any systematic differences between groups are due to the model of intervention.
Therapists who have had previous training in MBT will by default be allocated to the MBT
arm of the study.
MBT. The adaptation of MBT used in this study is a manualized, transdiagnostic model
designed for children aged 6–12 and their carers. It aims to promote adaptive ER by attending
to the capacity to understand oneself and others in terms of underlying mental states. MBT
consists of 6–8 sessions, delivered fortnightly, which can flexibly involve different members of
the family, with a primary focus on promoting mentalizing and emotion regulation in the par-
ent-child relationship (see Fig 3). Therapists randomly allocated to deliver treatment for the
intervention group will receive a 3-day MBT training, plus fortnightly group supervision to
support treatment fidelity. Practitioners are supported by an interactive online treatment man-
ual and the use of a self-completed MBT Fidelity Scale (https://manuals.annafreud.org/mbt-c/
index.html).
Treatment as Usual (TAU). The control group will be offered TAU. As there is no single
evidence-based treatment for this group, and because practice is not standardised across
CAMH services in England, TAU is likely to include CBT, parenting groups, and/or children’s
social skills groups. Scoping work with CAMH services has confirmed that 6–8 fortnightly
Fig 3. MBT logic model.
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sessions would be the usual length of intervention for this client group. Therapists will be pro-
vided with usual supervision, in line with existing practice in participating CAMHS teams. As
part of the study, more detailed data about TAU will be collected, including type of interven-
tion, treatment intensity and professionals offering treatment.
Discontinuation and withdrawal
Children and families can withdraw from either treatment or the trial without further explana-
tion at any point. Where children or families withdraw from treatment, they will be invited to
continue to participate in the trial. Reasons for discontinuing or withdrawal from the trial will
be recorded, where families agree to provide such a reason. If a child requires more intensive
care, such as inpatient hospitalization, the participant can be exited from the treatment, if this
is clinically indicated, but will be encouraged to remain part of the study.
Data collection
There will be three types of data collected: questionnaires, online tasks (subject to testing of
feasibility during the internal pilot phase) and a semi-structured interview.
Questionnaire data will be collected using a secure, browser-based web application for
developing, maintaining, and managing different types of surveys and securing online/offline
data collection (REDCap). Participants will have the option to self-complete these question-
naires by following a link to the REDCap webpage, or to complete them via video or telephone
call with a member of the research team. If collected during the video call, the responses to
questionnaires will not be video recorded. One questionnaire (Service Use Record) will be
completed by the participant’s local CAMHS team.
There are two tasks. A parent-child interaction task, and a child task (the Test of Emo-
tional Comprehension; TEC). These interactive tasks will take place during a video call
between the family and a member of the research team and part of the video call will be
recorded. The child’s responses to the questions in the TEC task will be collected in real-time
during the video call and entered directly into REDCap by the member of the research team
conducting the call. The parent-child interaction task is facilitated by the member of the
research team and the video call recorded; the recording is saved securely and later analysed
and scored. All data entered directly into REDCap is securely stored with UCL’s Data Safe
Haven.
The semi-structured interviews are part of the implementation and process evaluation (see
Outcome Measures). They will take place after treatment has ended during an online call and
audio recorded by the research team. The recording will be saved securely at on Anna Freud
Centre (AFC) secure servers and transcribed and analysed.
For families who do not have access to the technology needed to facilitate a video call, data
collection will take place over a telephone call, or else families will be given the opportunity to
access the necessary technology at the CAMHS where treatment is taking place. In order to
ensure that recruitment is inclusive, interpreters will be made use of to support data collection,
where required.
The use of REDCap automatically scores and transmits the data, reducing the risk of data
entry error. All research assistants are trained on the administering of the outcome measures.
A summary of data collection timepoints is provided in the schedule of enrolment, interven-
tions, and assessments (SPIRIT schedule) (Fig 1).
Participants’ personal data will be securely stored and only accessible by members of the
ERiC research team at AFC. At the end of the study, data will be archived in a safe and secure
location.
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Blinding
Parent/carers and children in the trial will not be blinded to intervention group. However,
research assistants and those involved in data collection and analysis (including coding of ER
tasks) will be blind to intervention group. Trial Managers will initiate the randomisation of
participants and the outcome of the randomisation will be sent directly to staff at the CAMHS
sites (see section ‘Randomisation’).
Outcome measures
Brief, well-validated tasks and questionnaires will be administered at four points: baseline, 8
weeks after start of treatment (mid-treatment), 16 weeks after start of treatment (end of treat-
ment) and 40 weeks after start of treatment (follow-up). An overview of all assessment points
and outcomes are detailed in the SPIRIT (Fig 1).
In order to maximize clinical validity, data will be gathered through multiple methods
(including questionnaire, interview and observational assessments) and from multiple per-
spectives (including self- and carer-reports). A consensus-based standard set of international
measures [41] has been used. All questionnaire measures selected have established reliability,
validity, utility/practicability and acceptability for this age group; they have also been reviewed
by our parent co-applicants to ensure that they are acceptable, relevant and culturally appro-
priate. The pilot phase of the study will be used to test the feasibility of online, task-based
assessment of parent-child ER capacity and mentalizing.
Primary outcome measure: Parent-rated Strengths and Difficulties Questionnaire (SDQ)
Total Difficulties Score [42]. The SDQ is one of the most widely used mental health measures
for children in the UK, covering both emotional (anxiety and depression) and behavioural
(ADHD and conduct) symptoms.
Secondary outcome measures will include a range of carer- and child-report assessments
and tasks to assess:
1. Emotional and behavioural problems,
• Me and My Feelings [43,44], a brief 16-item self-report measure for children, including
both emotional and behavioural sub-scales.
2. Personalized treatment goals,
• Goal Based Outcomes (parent/carer-defined) [45], a personalized goal-based measure
completed by parent/carers.
3. Parenting stress,
• Parental Stress Index–Short Form [46,47], a 36-item parent/carer-report measure of stress
and the parent-child relationship.
4. Parental mentalizing capacity,
• Parental Reflective Functioning Questionnaire [48], an 18-item parent/carer-report mea-
sure of parental mentalizing.
5. Service use and costs.
• Child and Adolescent Service Use Schedule (CA-SUS) [49], a questionnaire which records
service use 3 months prior to baseline, during the course of the treatment, and between
end of treatment and follow-up
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• Service Use Record, a questionnaire completed by CAMHS team to record the services
offered and attended between baseline and end of treatment, and end of treatment and fol-
low up.
6. Emotion regulation in child and parent will be assessed using the following:
• Emotional Awareness Questionnaire [50], a 30-item child self-report measure of emo-
tional awareness and mentalizing capacity.
• Test of Emotional Comprehension (TEC) [51], an online task to assess child’s capacity for
emotional understanding, ER and mentalizing capacity. This task takes approximately 15
minutes to complete. The test is divided into a set of stories in an established order. The
test booklet consists of illustrations with a story that is read for each situation. On every
page, there are four possible outcomes represented by emotional facial expressions.
Throughout the test, there are five options to choose from: happy, sad, angry, afraid,
alright. The children are asked to assign an emotion represented by a facial expression to
the situation. A digitalised version of the test booklet will be used in the current study. Fea-
sibility of its use will be tested in the internal pilot study.
• Emotion Regulation Checklist for Children [52], a 24-item parent/carer-report measure of
child’s ER capacity.
• Difficulties in Emotion Regulation Scale [53], a 36-item parent/carer report measure of
parent/carer’s ER capacity.
• Parent-Child Interaction Task, a parent/carer-child discussion task to assess capacity of
parent/carer to support ER and mentalizing in the parent/carer-child relationship, and to
assess child’s use of ER strategies. The researcher asks the child to recall a time when they
felt sad, and to talk to the parent/carer about what happened and how it made them feel.
After discussion, the interviewer asks the child: “What did you do to make your sad feel-
ings go away?” followed by one additional prompt to elicit further details e.g., “What else
did you do?”. This is repeated for three other emotions: happy, afraid, angry. The task is
video and audio recorded. The task is adapted from Davis et al. [54] and Shipman and
Zeman [55] and takes approximately 15 minutes to complete; the feasibility of its use will
be tested in the internal pilot study. The coding scheme developed by Davis et al. [54] will
be used to identify the child’s use of emotion regulation strategies. An adapted version of
the coding scheme developed by Vanwoerden [56] will be used to assesses degree of posi-
tive mentalizing, and degree of negative or maladaptive mentalizing (hyper or hypo menta-
lizing) within the dyad.
7. Treatment fidelity
Treatment fidelity will be assessed using the supervisor-report version of the MBT (Child)
Fidelity Scale (Malberg, Bate and Midgley [Unpublished]), which can also be used to sec-
ondarily examine how fidelity to the MBT model relates to treatment outcome.
8. Implementation and Process Evaluation:
• The Experiences of Therapy and Research Interview (Midgley, Ansaldo, Parkinson,
Holmes, Stapley and Target [Unpublished]), a semi-structured interview carried out with
parents and (where possible) the child, exploring the experience of change, the therapy
process and of participating in research.
• Online survey–examining stakeholder views on the scalability of the MBT intervention at
the end of the delivery phase.
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Monitoring of potential harm
To date there is a lack of agreement on suitable approaches to assessing and monitoring poten-
tial harm in the context of clinical trials for psychological treatments [57], especially in the con-
text of child and family treatments. For the purposes of this study, we will adopt a broad
definition of a Serious Adverse Event (sa). These include (in child or carer):
• Violent behaviour resulting in serious physical harm to another person
• Family relationship breakdown
• New or escalated self-harm
• New or escalated suicidal ideation (a preoccupation with suicide/thoughts about suicide,
with no clear plans to take own life)
• Suicidal intent (concrete and deliberate plans to end own life, with a conscious desire to
escape from the world and a resolve to act purposively in this regard, e.g., a suicide attempt.
This may be a deliberate action or disclosing of a deliberate action)
• Other life-threatening events
• Hospitalization due to drugs or alcohol, self-harm, or for psychiatric reasons (including, in-
patient hospitalization, or significant disability/incapacity)
• Death, including suicide
SAEs may occur during the course of being involved in the trial. This could be irrespective
of intervention or data collection or may be related to the intervention or data collection.
Ascertaining a relationship between an SAE and the intervention in the trial must be assessed
on a case-by-case basis. The individual identifying the SAE will therefore complete an SAE
form, which contains an assessment of relatedness. Any SAEs considered to be ‘likely related’
to the intervention will be reviewed with clinical leads in the CAMHS team where the SAE has
been identified and will qualify for expedited reporting to the ERiC Trial Steering Committee
(TSC), who are responsible for monitoring the study. SAEs which are both related and unex-
pected will also be reported to the Research Ethics Committee (REC). Expected occurrences in
the trial include the potential for some distress for participants as part of exploring painful
experiences as part of therapy. For further information on SAEs, please refer the ERiC SAE
procedure document.
Internal pilot
During the internal pilot, 40 children and families will be recruited in a sub-sample of
CAMHS teams. During this phase any potential barriers to training, recruitment, intervention
delivery or data collection will be identified. Towards the end of the delivery phase, a problem-
solving workshop will be held in each site included in the pilot phase of the trial, attended by
trial therapists, service managers and any other relevant CAMHS staff to gain feedback on
training, recruitment, delivery of intervention, and supervision procedures. Any issues arising,
as well as potential adaptations, will be discussed in meetings of the Trial Management Group
and the TSC, both during and upon completion of the internal pilot. Any recommended
changes will be implemented for the full trial. The MBT training team will also review levels of
model fidelity during the pilot phase, including any items on the scale which had the lowest
mean ratings, and any adaptations to training and/or supervision that should be made will be
identified, to improve model fidelity in the main study.
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The internal pilot will also be an opportunity to examine alternative approaches to the
assessment of emotion regulation. Although multiple measures exist to assess ER in children,
most clinical trials do not include the perspectives of both parents/carers and children. More-
over, recent research has highlighted the importance of assessing different components of ER
if we are to understand how ER relates to psychopathology, and which aspects of ER need to
be targeted in interventions. Due to the primarily deficit-focused approach in clinical psychol-
ogy, the field has long neglected the role of adaptive ER, especially in youth populations. This
is of particular importance, because recent evidence shows that the lack of adaptive–but not
presence of maladaptive—ER was significantly associated with psychopathology for children
with emotional disorders [58]. The pilot phase of this trial will therefore test the feasibility of
evaluating different elements of ER, including self- and carer-reported assessment alongside
task- and observation-based approaches. This will allow us to explore how different ER com-
ponents relate to different symptom clusters and examine which aspects of ER change due to
MBT treatment. If task- and observation-based approaches are shown to be feasible, and there
is indication that they add an additional perspective to the assessment of ER, including co-reg-
ulation in the parent-child relationship, they will be included in the full trial.
Data collected in the internal pilot will be used in the analysis for the full RCT: participants
recruited in the pilot will be included within the total number of participants for the full trial.
Statistical plan and data analysis for main trial
Sample size and power calculation. The total sample size for the study will be 320. The
power analysis was informed by an analysis of 71,763 UK CAMHS clinical records held by the
Child Outcomes Research Consortium (CORC, https://www.corc.uk.net/), as well as by pub-
lished psychotherapy trials in CAMHS settings. CORC data suggests that children meeting our
inclusion criteria have a mean SDQ Total Difficulties score of 24.6 at presentation to CAMHS,
with a standard deviation of 5.0. This score is our primary outcome. We assumed that the
smallest clinically meaningful post-treatment difference on the SDQ is 1.5 points, which is
equivalent to a standardised treatment effect difference of 0.3. The power analysis aimed to
establish the number of children per therapist to give at least 80% power to detect this effect at
the 5% significance level using a two-sided test. The statistical model will account for clustering
of children within therapists, and of therapists within the CAMHS, via random intercepts. We
will adjust for baseline SDQ scores.
We calculated the required sample size based on published formulae [59] and made the fol-
lowing assumptions: The within-patient correlation was assumed to be within-patient = 0.6,
which is close to the median value of 0.59 estimated by a meta-analysis of within-patient corre-
lations [60]. We estimated that 40 therapists will participate in the study and assumed a thera-
pist effect of ICC therapist = 0.02. We think this ICC is conservative. There is little data on
therapist ICCs in CAMHS settings specifically, but the recent Improving Mood with Psychoan-
alytic and Cognitive Therapies (IMPACT) trial, set in English CAMHS, reported ICC <0.01
[61]. A smaller therapist ICC would increase power. The power analysis assumed that outcomes
do not vary by CAMHS, which is also conservative. If there was intra-site correlation, power
would increase, since each service would act as its own control. Given these assumptions, and
allowing for 15% loss to follow-up, the total required sample size is N= 320 (160 children per
treatment group, 8 children per therapist). The calculated power under this design is 80.8%.
Statistical data analysis plan for the main trial
The primary analysis aims to establish the difference between the MBT and TAU groups in the
SDQ Total Difficulties score at the end of treatment (16 weeks, Hypothesis 1). Children are
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clustered within therapists, who in turn are clustered within CAMH services. The primary
analysis model is a linear mixed effects model, with random intercepts for therapists and ser-
vices, controlling for SDQ and age group at baseline. The evidence for a difference in SDQ
scores after treatment will be assessed via a two-sided t-test of the coefficient of the treatment
indicator variable, using a parametric bootstrap to estimate standard errors. A 5% significance
level will be used as a cut-off to support a finding of superiority of MBT over TAU.
Analogous models will be used to assess the evidence regarding a difference between the
MBT and TAU groups with respect to secondary outcomes (Hypothesis 2).
To investigate potential mediation of the effect of MBT on child mental health via improve-
ment in emotion regulation (Hypothesis 3), we will conduct a mediation analysis using treat-
ment allocation as the exposure, the Emotion Awareness Questionnaire (EAQ) score as the
mediator, and the SDQ Total Difficulties Score as the outcome. We will additionally adjust for
both EAQ and SDQ scores at baseline. Summary scores from the validated scales will be used,
rather than latent variable scores, in order to maintain consistency with the effect estimates of
the primary analysis. We will conduct an analogous mediation analysis using parental emotion
regulation, assessed by the Difficulties in Emotion Regulation Scale (DERS). More complex
mediation models will be developed using exploratory analyses.
To examine whether the improvement in child SDQ Total Difficulties is clinically signifi-
cant at the individual level, the reliable change index [62] will be calculated for each participant
using the SDQ scores at baseline and post-intervention. Children will be classified as recov-
ered, improved, unchanged, or deteriorated. We will compare the distribution of this classifi-
cation in the MBT and TAU groups using an ordinal logistic regression model.
We will also estimate the difference in treatment effect between MBT and TAU on SDQ
Total Difficulties and all secondary outcomes at 40-week follow-up, using statistical models
analogous to those for the primary analysis.
All primary and secondary analyses will be carried out as intention-to-treat analyses. If
some values at the primary endpoint are missing, the following strategy will be employed: 1)
Evaluate likely processes of missingness and assess their potential for causing bias; 2) Conduct
a complete cases analysis as the primary analysis; (3) Conduct information-anchored sensitiv-
ity analyses using controlled multiple imputation under MNAR assumptions to gauge the sen-
sitivity of the trial results to potential violations in the MAR/MCAR assumptions [63,64].
Economic evaluation
The aim of the economic analysis will be to provide an assessment of the relative costs and ben-
efits of MBT compared to TAU over the 40-week follow-up period. The study perspective will
be that of the NHS and personal social services sectors, including those provided within the
education sector. Health and social care service use will be collected using the CA-SUS ques-
tionnaire at baseline (covering the last 3 months) and at the 16- and 40-week follow-up points
(covering the period since the last assessment). In addition, a Service Use Record will be com-
pleted by the CAMHS team at follow up to record the services offered and attended during the
trial period. Collecting resource use at baseline will better characterise what ‘treatment as
usual’ involves in terms of health care resources and allow for an adjustment for any potential
baseline imbalances. Service use will be valued using PSSRU unit costs of health and social
care [65] and national tariffs (NHS Reference Costs). MBT and TAU sessions will be costed
using a bottom-up approach and using data on staff use (contacts). We will adopt a cost-conse-
quences analysis (CCA) to report value for money of MBT versus TAU at 40 weeks. The CCA
will report a disaggregated summary of all the costs and benefits of MBT versus TAU, without
attempting to combine them into a single measure such as a cost-effectiveness or cost-utility
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ratio. This allows decision makers to decide which costs and benefits are most relevant to their
decision context, and whether the relevant benefits are worth any additional costs that might
be incurred. We will report mean costs and consequences, together with 95% confidence inter-
vals, by treatment groups at baseline, 16 and 40 weeks. The consequences of interest for the
CCA will be: SDQ and a range of carer and child-reported measures: The range of costs to be
reported: intervention, medication, primary care, hospital care, social care, school-based ser-
vice use. Costs and consequences will not be discounted given the short follow-up period.
Implementation and process evaluation
Treatment fidelity. Fidelity to the MBT model will be assessed using the MBT Fidelity
Scale (Malberg, Bate and Midgley [Unpublished]), completed by supervisors.
Experience of therapy and the change process from the service user perspective. In
order to examine the experience of therapy and the change process, parents/carers and chil-
dren who have agreed to an optional interview in the consent form will be interviewed at the
end of intervention (16 weeks), using an adapted version of the Experiences of Therapy and
Research Interview (Midgley, Ansaldo, Parkinson, Holmes, Stapley and Target [Unpub-
lished]),to explore their experiences of therapy and the change process. We aim to interview at
least 20% of parents/carers and (where possible) children. The interviews will explore parents/
carers’ and children’s experiences of the intervention offered, how acceptable they found it,
and any facilitators or barriers they found in engaging with the programme. For those who
stopped attending the MBT, or who had low attendance, there will be an exploration of reasons
for stopping/non-attendance, and of potential barriers to participation. Interviews will be
audio-recorded and transcribed. Interviews with children may include the use of drawings, to
enable a richer understanding of their experiences of therapy.
Interviews with children and parents/carers will be transcribed, and the data analysed using
Framework Analysis [66], a qualitative method which allows both a priori issues and emergent
data-driven themes to guide the development of the analytic process. Drawings, where
included, will be incorporated at two stages of the analysis, using a specific qualitative analysis
method used previously by members of the research team [67].
Implementation and potential for scalability. A link to an online survey will be emailed
to all stakeholders in the CAMHS taking part (practitioners, administrative staff, and manag-
ers) towards the end of the intervention phase to gain their views on the scalability of the MBT
intervention at the end of the delivery phase of the full RCT. Once the online survey is com-
pleted, a single problem-solving workshop, including members of the research team, and
selected practitioners, administrative staff, and managers, will be organised, in order to review
the findings of the survey and discuss potential ways in which any identified barriers to post-
trial implementation could be overcome, if the intervention is demonstrated to be effective.
Trial oversight
A Trial Manager will oversee day-to-day management of the trial, with two research assistants.
Trial staff will also include a statistician, a health economist, a clinical lead (with responsibility
for training and ongoing supervision of CAMHS clinicians) and an expert by experience who
will review all procedures and materials, Chair the Parent/Carer Advisory Group and help to
problem solve operational issues. The principal and associated investigators will oversee all
study operations. Clinical management will be provided by Leads in each CAMHS Trust. A
Trial Management Committee will meet weekly to manage the day-to-day running of the trial
(chief investigator, trial managers, research assistants, and site leads). A TSC will meet twice a
year to provide oversight to ensure that the project is conducted according to the UK’s
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Research Governance Framework. A Data Monitoring and Ethics Committee (DMEC), com-
prised of experts who are independent of the sponsor (Anna Freud), will oversee progression
of the data collection and undertake regular monitoring of the MBT intervention arm for signs
of deterioration. This will be done by reviewing items on measures identified as markers of
deterioration in the child. Unlike the TSC, the DMEC will have access to unblinded, compara-
tive data. DMEC meetings will take place six-monthly, where required, once data collection
has commenced, usually two weeks prior to TSC meetings in order for them to report to the
TSC.
User involvement
A parent co-applicant and an Advisory Group of parents/carers and young people with experi-
ences of child mental health services will continue to inform study design and delivery, specifi-
cally: a) recruitment of research staff; b) selection of outcome measures; c) ensuring
information sheets and consent forms are designed with consideration of the needs of families;
d) designing data management systems that have the confidence of families (timing of assess-
ments, settings, confidentiality); e) co-developing structured qualitative interviews; and f) dis-
semination to public.
Ethical considerations
Ethical approval was granted by the NHS Health Research Authority and necessary local per-
missions, and information governance approvals, will be obtained before patient recruitment.
The research will be conducted in line with relevant ethical guidelines, including the Declara-
tion of Helsinki. Voluntary and fully informed eConsent will be obtained from parents/carers
and informed assent from children. Families will be given Information Sheets (parent and
child versions) in age-appropriate language, co-developed in collaboration with the Young
Champions group at the AFC, as well as with the parent/carer representatives. Families will
have the right to withdraw from the study at any point, without needing to give a reason. Their
decisions concerning participation will not in any way affect their access to the usual support
and treatment in CAMHS. Data will be anonymized, and personal details stored securely in
accordance with General Data Protection Regulations 2018 (GDPR). Safety and child protec-
tion concerns will be closely monitored in line with safeguarding procedures. The TSC will
monitor the safety of participants and child protection concerns. Where safeguarding concerns
are identified, the CI and local site lead will be immediately informed, and the CI will also
inform the local safeguarding oversight group (SOG). Any safeguarding issues will be reported
to the TSC, ethics committee, and funder.
Trial registration
The trial has been registered with the International Standard Randomised Controlled Trial
Number (ISRCTN) registry (11620914).
Data protection
A data protection impact assessment has been completed and agreed by the Data Protection
Officer at the AFC. All participants will receive a data privacy notice alongside the study infor-
mation sheet, in line with GDPR regulations. Access to the trial dataset will be covered by the
collaboration agreement between the trial partner organisations. Only certain members of the
CORE research team will have access to identifiable information about participants (NM, JEC,
BM, CE, PC, AK and NP).
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Discussion
One of the main barriers to children receiving evidence-based interventions in CAMHS is the
lack of research evaluating transdiagnostic treatments that target mechanisms underlying the
mixed internalizing and externalizing difficulties experienced by many young people. Research
is often organised around specific diagnoses, but these children do not fit easily within diagnos-
tic frameworks, meaning that there is a lack of evidence-based interventions available for them.
This trial will address this research-practice gap. Developed in collaboration with experts by
experience and service providers, this study will be the first full-scale, sufficiently powered clin-
ical trial to evaluate MBT as an intervention for school-age children with mixed emotional and
behavioural difficulties. By targeting an underlying mechanism (ER), which has been shown to
play a role in a range of mental health difficulties, it has the potential to identify a brief, manua-
lized treatment that may be effective for a significant proportion of school-aged children
referred to mental health services. MBT can be delivered by a range of mental health profes-
sionals in a real-world setting, mapping on well to the transdiagnostic THRIVE model used to
organise child mental health services across the UK and internationally [68].
Further, the qualitative component of this research will seek to identify what makes MBT
‘therapeutic’ from the perspective of families. Interviews will explore young people and parent/
carers’ understanding of what makes treatment effective, why, and the role of ER in this pro-
cess. This will provide valuable insights, informing our understanding of which treatments
work for whom, and under what conditions [69].
This study is innovative in the use of multiple measures to assess different components of
ER, integrating the perspectives of the child and the parent/carer. This will allow us to explore
how different ER components relate to different symptom clusters and examine which aspects
of ER change due to MBT treatment. Furthermore, most research focuses on ER within the
individual, but for school-age children ER happens mostly in relationship to others; by exam-
ining parent-child co-regulation of emotions, this study represents a significant methodologi-
cal advancement. In this way, this study is aligned with the “Roadmap for Mental Health
Research in Europe” [70], in that it seeks to identify and interrogate putative mechanisms of
change.
Many studies evaluating treatments in child mental health settings are limited by a lack of
follow-up [71]. This study is ambitious in that it will include a six-month follow-up post-inter-
vention. If MBT proves to be superior to TAU in the first 40 weeks, we will ask families for
consent to be re-contacted, so that a long-term follow-up study can answer the question of
whether the beneficial effects are maintained two and five years from baseline.
The Medical Research Council guidance on evaluation of complex interventions [72]
emphasises the importance of including a process evaluation and an economic evaluation
within clinical trials. This study is ambitious in including both. The health-economic evalua-
tion will improve our understanding of the economic implications, and value for money, of
implementing MBT compared to current treatment options. In doing so, the trial will better
map and evaluate ‘treatment as usual’ for a group of children who are poorly served by current
evidence-based treatment guidelines, as they do not fit easily within existing diagnostic frame-
works. The process evaluation will help to explain discrepancies between expected and
observed outcomes, to understand how context influences outcomes, and to provide insights
to aid implementation. Taken together, the health-economic and process evaluation will
ensure that the findings of this evaluation are relevant and actionable for decision-makers,
ensuring real world impact for children and families.
It is well established that child mental health is strongly associated with levels of deprivation
and poverty [73] and the Covid-19 pandemic is likely to have further increased inequalities in
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mental health. The Centre for Mental Health predicts that up to 1.5 million children and
young people in the UK aged under 18 will need new or additional mental health support as a
direct consequence of the crisis [74]. Developing effective interventions for these children and
families may help to mitigate health inequalities across the lifespan, hopefully preventing diffi-
culties from becoming entrenched and persisting into adulthood. In evaluating MBT for chil-
dren aged 6–12, the project will address the UN Sustainable Development Goal: ‘ensure
healthy lives and promote well-being for all at all ages.’
Dissemination
The findings of the study will be disseminated to the academic and scientific community via
conference presentations and publication of findings in leading peer-review journals.
Working with an Advisory Group of parents/carers, we will create and publish a video sum-
mary of the full trial results and an infographic which will be disseminated through our social
media and Learning Network of almost 30,000 allied professionals, enabling children and fam-
ilies to be better informed about evidence-based treatment models, and to empower practi-
tioners to learn about the study findings. We will also create briefing notes which will be
shared with policy makers.
If MBT is shown to be clinically- and cost-effective, dissemination into practice will be facil-
itated by the AFC’s track-record of developing and delivering training programmes to mental
health practitioners, including the development of Child Wellbeing Practitioners (CWP), as
well as providing guidance to healthcare managers and commissioners of services, and to
national and international bodies responsible for developing clinical guidelines (e.g., NICE).
Training materials are already translated into several languages, and a web-based MBT treat-
ment manual allows for rapid dissemination of training. There are clear pathways for practi-
tioners who are trained during the study to go on to become supervisors themselves, thus
embedding ownership and sustainability into the study design.
The UK’s long-term plan for the NHS promises that 100% of children and young people
who need specialist care can access it within a decade, but there is a deficit in evidence-based
models that can be delivered by a wide range of professionals to children with a broad range of
presenting difficulties. If this study demonstrates that primary mental health workers can be
trained to deliver effective MBT, then this approach has the potential to become central to
meeting the government’s ambitions for child mental health services.
Trial status
This trial began recruitment in April 2023.
This manuscript is based in protocol version 2.
Supporting information
S1 Checklist. SPIRIT 2013 checklist: Recommended items to address in a clinical trial pro-
tocol and related documents*.
(DOC)
S1 File.
(PDF)
S2 File.
(PDF)
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Acknowledgments
The authors would like to thank the Kavli Trust, for funding this study, and the Anna Freud
Centre, University College London and the two NHS sites (Oxford Health NHS Foundation
Trust and Barnet, Enfield and Haringey Mental Health NHS Trust) for their support to deliver
the ERiC trial. We would also like to thank Pip Patrick for her contribution to this work.
Author Contributions
Conceptualization: Nick Midgley, Mark Carter, Lisa Coffman, Julian Edbrooke-Childs, Sus-
annah Marks, Bettina Moltrecht, Emma Morris.
Formal analysis: Peter Martin.
Funding acquisition: Nick Midgley, Mark Carter, Lisa Coffman, Julian Edbrooke-Childs,
Peter Fonagy, Manuel Gomes, Susannah Marks, Peter Martin, Bettina Moltrecht, Emma
Morris.
Investigation: Anoushka Kapoor, Nikola Pokorna.
Methodology: Nick Midgley, Julian Edbrooke-Childs, Manuel Gomes, Peter Martin, Bettina
Moltrecht.
Project administration: Polly Casey, Chloe Edridge.
Supervision: Nick Midgley.
Writing – original draft: Nick Midgley, Rose Mortimer, Manuel Gomes, Peter Martin, Bettina
Moltrecht, Tara McFarquhar.
Writing – review & editing: Mark Carter, Polly Casey, Lisa Coffman, Julian Edbrooke-Childs,
Chloe Edridge, Peter Fonagy, Anoushka Kapoor, Susannah Marks, Emma Morris, Nikola
Pokorna.
References
1. Vizard T, Sadler K, Ford T, Newlove-Delgado T, McManus S, Marcheselli F, et al. Mental Health of Chil-
dren and Young People in England, 2020) Wave 1 follow up to the 2017 survey. 2020. Available: https://
digital.nhs.uk/data-and-information/publications/statistical/mental-health-of-children-and-young-
people-in-england/2020-wave-1-follow-up/copyright
2. Bearman SK, Weisz JR. Review: Comprehensive treatments for youth comorbidity—evidence-guided
approaches to a complicated problem. Child Adolesc Ment Health. 2015; 20: 131–141. https://doi.org/
10.1111/camh.12092 PMID: 26392814
3. Jeppesen P, Wolf RT, Nielsen SM, Christensen R, Plessen KJ, Bilenberg N, et al. Effectiveness of
Transdiagnostic Cognitive-Behavioral Psychotherapy Compared With Management as Usual for Youth
With Common Mental Health Problems. JAMA Psychiatry. 2021; 78: 250. https://doi.org/10.1001/
jamapsychiatry.2020.4045 PMID: 33355633
4. McElroy E, Shevlin M, Murphy J, McBride O. Co-occurring internalizing and externalizing psychopathol-
ogy in childhood and adolescence: a network approach. Eur Child Adolesc Psychiatry. 2018; 27: 1449–
1457. https://doi.org/10.1007/s00787-018-1128-x PMID: 29520540
5. Rhee SH, Lahey BB, Waldman ID. Comorbidity Among Dimensions of Childhood Psychopathology:
Converging Evidence From Behavior Genetics. Child Dev Perspect. 2015; 9: 26–31. https://doi.org/10.
1111/cdep.12102 PMID: 26019716
6. Garber J, Weersing VR. Comorbidity of anxiety and depression in youth: Implications for treatment and
prevention. Clinical Psychology: Science and Practice. 2010; 17: 293–306. https://doi.org/10.1111/j.
1468-2850.2010.01221.x PMID: 21499544
7. Chu BC, Temkin AB, Toffey K. Transdiagnostic Mechanisms and Treatment for Children and Adoles-
cents. Oxford University Press; 2016. https://doi.org/10.1093/oxfordhb/9780199935291.013.10
8. Chu BC, Crocco ST, Esseling P, Areizaga MJ, Lindner AM, Skriner LC. Transdiagnostic group behav-
ioral activation and exposure therapy for youth anxiety and depression: Initial randomized controlled
PLOS ONE
Emotion regulation in children (ERiC): A protocol for mentalization based treatment for school-age children
PLOS ONE | https://doi.org/10.1371/journal.pone.0289503 August 17, 2023 19 / 23
trial. Behaviour Research and Therapy. 2016; 76: 65–75. https://doi.org/10.1016/j.brat.2015.11.005
PMID: 26655958
9. Kennedy SM, Tonarely NA, Sherman JA, Ehrenreich-May J. Predictors of treatment outcome for the
unified protocol for transdiagnostic treatment of emotional disorders in children (UP-C). J Anxiety Dis-
ord. 2018; 57: 66–75. https://doi.org/10.1016/j.janxdis.2018.05.004 PMID: 29776708
10. Beauchaine TP, Cicchetti D. Emotion dysregulation and emerging psychopathology: A transdiagnostic,
transdisciplinary perspective. Dev Psychopathol. 2019; 31: 799–804. https://doi.org/10.1017/
S0954579419000671 PMID: 31290735
11. Weissman DG, Bitran D, Miller AB, Schaefer JD, Sheridan MA, McLaughlin KA. Difficulties with emotion
regulation as a transdiagnostic mechanism linking child maltreatment with the emergence of psychopa-
thology. Dev Psychopathol. 2019; 31: 899–915. https://doi.org/10.1017/S0954579419000348 PMID:
30957738
12. Cludius B, Mennin D, Ehring T. Emotion regulation as a transdiagnostic process. Emotion. 2020; 20:
37–42. https://doi.org/10.1037/emo0000646 PMID: 31961175
13. Daniel SK, Abdel-Baki R, Hall GB. The Protective Effect of Emotion Regulation on Child and Adolescent
Wellbeing. J Child Fam Stud. 2020; 29: 2010–2027. https://doi.org/10.1007/s10826-020-01731-3
14. Compas BE, Jaser SS, Bettis AH, Watson KH, Gruhn MA, Dunbar JP, et al. Coping, emotion regulation,
and psychopathology in childhood and adolescence: A meta-analysis and narrative review. Psychol
Bull. 2017; 143: 939–991. https://doi.org/10.1037/bul0000110 PMID: 28616996
15. Kim-Spoon J, Cicchetti D, Rogosch FA. A Longitudinal Study of Emotion Regulation, Emotion Lability-
Negativity, and Internalizing Symptomatology in Maltreated and Nonmaltreated Children. Child Dev.
2013; 84: 512–527. https://doi.org/10.1111/j.1467-8624.2012.01857.x PMID: 23034132
16. Thomson N, Centifanti L, Lemerise E. Emotion Regulation and Conduct Disorder: the role of Callous-
Unemotional Traits. In: Essau C, LeBlanc S, Ollendick T, editors. Emotion Regulation and Psychopa-
thology in Children and Adolescents. Oxford, UK: Oxford University Press; 2017. pp. 129–153.
17. Moltrecht B, Deighton J, Patalay P, Edbrooke-Childs J. Effectiveness of current psychological interven-
tions to improve emotion regulation in youth: a meta-analysis. Eur Child Adolesc Psychiatry. 2021; 30:
829–848. https://doi.org/10.1007/s00787-020-01498-4 PMID: 32108914
18. Fonagy P, Gergely G, Jurist EL, Target M. Affect regulation, mentalization and the development of the
self. New York: Routledge; 2002.
19. Bateman A, Fonagy P. Mentalization based treatment for borderline personality disorder. World Psychi-
atry. 2010; 9: 11–15. https://doi.org/10.1002/j.2051-5545.2010.tb00255.x PMID: 20148147
20. Rothschild-Yakar L, Stein D, Goshen D, Shoval G, Yacobi A, Eger G, et al. Mentalizing Self and Other
and Affect Regulation Patterns in Anorexia and Depression. Front Psychol. 2019; 10. https://doi.org/10.
3389/fpsyg.2019.02223 PMID: 31681070
21. Schwarzer N-H, Nolte T, Fonagy P, Gingelmaier S. Mentalizing and emotion regulation: Evidence from
a nonclinical sample. International Forum of Psychoanalysis. 2021; 30: 34–45. https://doi.org/10.1080/
0803706X.2021.1873418
22. Bizzi F, Ensink K, Borelli JL, Mora SC, Cavanna D. Attachment and reflective functioning in children
with somatic symptom disorders and disruptive behavior disorders. Eur Child Adolesc Psychiatry. 2019;
28: 705–717. https://doi.org/10.1007/s00787-018-1238-5 PMID: 30350093
23. Ensink K, Be
´gin M, Normandin L, Fonagy P. Maternal and child reflective functioning in the context of
child sexual abuse: pathways to depression and externalising difficulties. Eur J Psychotraumatol. 2016;
7. https://doi.org/10.3402/ejpt.v7.30611 PMID: 26822865
24. Halfon S, Bekar O, Gu¨rleyen B. An empirical analysis of mental state talk and affect regulation in two
single-cases of psychodynamic child therapy. Psychotherapy. 2017; 54: 207–219. https://doi.org/10.
1037/pst0000113 PMID: 28581329
25. Sharp C, Venta A. Mentalizing problems in children and adolescents. In: Midgley N, Vrouva I, editors.
Minding the child: Mentalization-based interventions with children, young people and their families.
Routledge/Taylor & Francis Group; 2012. pp. 35–53.
26. Charpentier Mora S, Bastianoni C, Koren-Karie N, Cavanna D, Tironi M, Bizzi F. Parental Mentalizing
during Middle Childhood: How Is the Adoption of a Reflective Stance Associated with Child’s Psycholog-
ical Outcomes? Int J Environ Res Public Health. 2022; 19: 6205. https://doi.org/10.3390/
ijerph19106205 PMID: 35627742
27. Huth-Bocks AC, Muzik M, Beeghly M, Earls L, Stacks AM. Secure base scripts are associated with
maternal parenting behavior across contexts and reflective functioning among trauma-exposed moth-
ers. Attach Hum Dev. 2014; 16: 535–556. https://doi.org/10.1080/14616734.2014.967787 PMID:
25319230
PLOS ONE
Emotion regulation in children (ERiC): A protocol for mentalization based treatment for school-age children
PLOS ONE | https://doi.org/10.1371/journal.pone.0289503 August 17, 2023 20 / 23
28. Rutherford HJV, Booth CR, Luyten P, Bridgett DJ, Mayes LC. Investigating the association between
parental reflective functioning and distress tolerance in motherhood. Infant Behav Dev. 2015; 40: 54–
63. https://doi.org/10.1016/j.infbeh.2015.04.005 PMID: 26025253
29. Rutherford HJV, Goldberg B, Luyten P, Bridgett DJ, Mayes LC. Parental reflective functioning is associ-
ated with tolerance of infant distress but not general distress: Evidence for a specific relationship using
a simulated baby paradigm. Infant Behav Dev. 2013; 36: 635–641. https://doi.org/10.1016/j.infbeh.
2013.06.008 PMID: 23906942
30. Camoirano A. Mentalizing Makes Parenting Work: A Review about Parental Reflective Functioning and
Clinical Interventions to Improve It. Front Psychol. 2017; 8. https://doi.org/10.3389/fpsyg.2017.00014
PMID: 28163690
31. Borelli JL, Hong K, Rasmussen HF, Smiley PA. Reflective functioning, physiological reactivity, and
overcontrol in mothers: Links with school-aged children’s reflective functioning. Dev Psychol. 2017; 53:
1680–1693. https://doi.org/10.1037/dev0000371 PMID: 28639804
32. Esbjørn BH, Pedersen SH, Daniel SIF, Hald HH, Holm JM, Steele H. Anxiety levels in clinicallyreferred
children and their parents: Examining the unique influence of self-reported attachment styles and inter-
view-based reflective functioning in mothers and fathers. British Journal of Clinical Psychology. 2013;
52: 394–407. https://doi.org/10.1111/bjc.12024 PMID: 24117912
33. Heron-Delaney M, Kenardy JA, Brown EA, Jardine C, Bogossian F, Neuman L, et al. Early Maternal
Reflective Functioning and Infant Emotional Regulation in a Preterm Infant Sample at 6 Months Cor-
rected Age. J Pediatr Psychol. 2016; 41: 906–914. https://doi.org/10.1093/jpepsy/jsv169 PMID:
26811019
34. Smaling HJA, Huijbregts SCJ, van der Heijden KB, Hay DF, van Goozen SHM, Swaab H. Prenatal
Reflective Functioning and Development of Aggression in Infancy: the Roles of Maternal Intrusiveness
and Sensitivity. J Abnorm Child Psychol. 2017; 45: 237–248. https://doi.org/10.1007/s10802-016-0177-
1PMID: 27344154
35. Vogt KS, Norman P. Is mentalization-based therapy effective in treating the symptoms of borderline per-
sonality disorder? A systematic review. Psychology and Psychotherapy: Theory, Research and Prac-
tice. 2019; 92: 441–464. https://doi.org/10.1111/papt.12194 PMID: 30099834
36. Midgley N, Vrouva I. Mentalization-based interventions with children, young people, and families. Lon-
don, UK: Routledge; 2012.
37. Keaveny E, Midgley N, Asen E, Bevington D, Fearon P, Fonagy P, et al. Minding the family mind: The
development and initial evaluation of mentalization-based treatment for families. In: Midgley N, Vrouva
I, editors. Minding the child: Mentalization-based interventions with children, young people and their
families. Routledge/Taylor & Francis Group; 2012. pp. 98–112.
38. Halfon S, Besiroglu B. Parental reflective function and children’s attachment-based mental state talk as
predictors of outcome in psychodynamic child psychotherapy. Psychotherapy. 2021; 58: 81–94. https://
doi.org/10.1037/pst0000347 PMID: 33119373
39. Midgley N, Sprecher EA, Sleed M. Mentalization-Based Interventions for Children Aged 6–12 and Their
Carers: A Narrative Systematic Review. Journal of Infant, Child, and Adolescent Psychotherapy. 2021;
20: 169–189. https://doi.org/10.1080/15289168.2021.1915654
40. R Core Team. R: A language and environment for statistical computing. Vienna, Austria: R Foundation
for Statistical Computing; 2021. Available: https://www.R-project.org/
41. Krause KR, Chung S, Adewuya AO, Albano AM, Babins-Wagner R, Birkinshaw L, et al. International
consensus on a standard set of outcome measures for child and youth anxiety, depression, obsessive-
compulsive disorder, and post-traumatic stress disorder. Lancet Psychiatry. 2021; 8: 76–86. https://doi.
org/10.1016/S2215-0366(20)30356-4 PMID: 33341172
42. Goodman R. Psychometric Properties of the Strengths and Difficulties Questionnaire. J Am Acad Child
Adolesc Psychiatry. 2001; 40: 1337–1345. https://doi.org/10.1097/00004583-200111000-00015 PMID:
11699809
43. Deighton J, Tymms P, Vostanis P, Belsky J, Fonagy P, Brown A, et al. The Development of a School-
Based Measure of Child Mental Health. J Psychoeduc Assess. 2013; 31: 247–257. https://doi.org/10.
1177/0734282912465570 PMID: 25076806
44. Patalay P, Deighton J, Fonagy P, Vostanis P, Wolpert M. Clinical validity of the Me and My School ques-
tionnaire: a self-report mental health measure for children and adolescents. Child Adolesc Psychiatry
Ment Health. 2014; 8: 17. https://doi.org/10.1186/1753-2000-8-17 PMID: 24963344
45. Law D, Jacob J. Goals and Goal Based Outcomes (GBOs): Some useful information. London, UK:
CAMHS Press; 2015.
46. Abidin R. Parenting Stress Index. Odessa, FL: Psychological Assessment Resources; 2012.
PLOS ONE
Emotion regulation in children (ERiC): A protocol for mentalization based treatment for school-age children
PLOS ONE | https://doi.org/10.1371/journal.pone.0289503 August 17, 2023 21 / 23
47. Haskett ME, Ahern LS, Ward CS, Allaire JC. Factor Structure and Validity of the Parenting Stress
Index-Short Form. Journal of Clinical Child & Adolescent Psychology. 2006; 35: 302–312. https://doi.
org/10.1207/s15374424jccp3502_14 PMID: 16597226
48. Luyten P, Mayes LC, Nijssens L, Fonagy P. The parental reflective functioning questionnaire: Develop-
ment and preliminary validation. PLoS One. 2017; 12: e0176218. https://doi.org/10.1371/journal.pone.
0176218 PMID: 28472162
49. Byford S, Barrett B, Roberts C, Wilkinson P, Dubicka B, Kelvin RG, et al. Cost-effectiveness of selective
serotonin reuptake inhibitors and routine specialist care with and without cognitive–behavioural therapy
in adolescents with major depression. British Journal of Psychiatry. 2007; 191: 521–527. https://doi.org/
10.1192/bjp.bp.107.038984 PMID: 18055956
50. Rieffe C, Oosterveld P, Miers AC, Meerum Terwogt M, Ly V. Emotion awareness and internalising
symptoms in children and adolescents: The Emotion Awareness Questionnaire revised. Pers Individ
Dif. 2008; 45: 756–761. https://doi.org/10.1016/j.paid.2008.08.001
51. Pons F, Harris P. TEC (Test of Emotion Comprehension). Oxford, UK: Oxford University Press; 2000.
52. Shields A, Cicchetti D. Emotion regulation among school-age children: The development and validation
of a new criterion Q-sort scale. Dev Psychol. 1997; 33: 906–916. https://doi.org/10.1037//0012-1649.
33.6.906 PMID: 9383613
53. Gratz KL, Roemer L. Multidimensional Assessment of Emotion Regulation and Dysregulation: Develop-
ment, Factor Structure, and Initial Validation of the Difficulties in Emotion Regulation Scale. J Psycho-
pathol Behav Assess. 2004; 26: 41–54. https://doi.org/10.1023/B:JOBA.0000007455.08539.94
54. Davis EL, Levine LJ, Lench HC, Quas JA. Metacognitive emotion regulation: Children’s awareness that
changing thoughts and goals can alleviate negative emotions. Emotion. 2010; 10: 498–510. https://doi.
org/10.1037/a0018428 PMID: 20677867
55. Shipman KL, Zeman J. Emotional Understanding: A Comparison of Physically Maltreating and Nonmal-
treating Mother-Child Dyads. J Clin Child Psychol. 1999; 28: 407–417. https://doi.org/10.1207/
S15374424jccp280313 PMID: 10446690
56. Vanwoerden S. The Development and Validation of an Observational Coding System for Real-Time
Parent-Adolescent Mentalizing. PhD Thesis, University of Houston. 2020. Available: https://hdl.handle.
net/10657/7266
57. Jonsson U, Alaie I, Parling T, Arnberg FK. Reporting of harms in randomized controlled trials of psycho-
logical interventions for mental and behavioral disorders: A review of current practice. Contemp Clin Tri-
als. 2014; 38: 1–8. https://doi.org/10.1016/j.cct.2014.02.005 PMID: 24607768
58. Braet C, Theuwis L, Van Durme K, Vandewalle J, Vandevivere E, Wante L, et al. Emotion Regulation in
Children with Emotional Problems. Cognit Ther Res. 2014; 38: 493–504. https://doi.org/10.1007/
s10608-014-9616-x
59. Moerbek M, Teerenstra S. Power analysis of trials with multilevel data. Boca Raton, FL: CRC Press;
2016.
60. Balk EM, Earley A, Patel K, Trikalinos TA, Dahabreh IJ. Empirical Assessment of Within-Arm Correla-
tion Imputation in Trials of Continuous Outcomes. Rockville, MD: Agency for Healthcare Research and
Quality (US); 2012. Available: http://www.ncbi.nlm.nih.gov/pubmed/23326900
61. Goodyer IM, Reynolds S, Barrett B, Byford S, Dubicka B, Hill J, et al. Cognitive behavioural therapy and
short-term psychoanalytical psychotherapy versus a brief psychosocial intervention in adolescents with
unipolar major depressive disorder (IMPACT): a multicentre, pragmatic, observer-blind, randomised
controlled superiority trial. Lancet Psychiatry. 2017; 4: 109–119. https://doi.org/10.1016/S2215-0366
(16)30378-9 PMID: 27914903
62. Jacobson NS, Truax P. Clinical significance: A statistical approach to defining meaningful change in
psychotherapy research. J Consult Clin Psychol. 1991; 59: 12–19. https://doi.org/10.1037//0022-006x.
59.1.12 PMID: 2002127
63. Cro S, Morris TP, Kenward MG, Carpenter JR. Reference-based sensitivity analysis via multiple impu-
tation for longitudinal trials with protocol deviation. Stata J. 2016; 16: 443–463. PMID: 29398978
64. Cro S, Carpenter JR, Kenward MG. Information-Anchored Sensitivity Analysis: Theory and Application.
J R Stat Soc Ser A Stat Soc. 2019; 182: 623–645. https://doi.org/10.1111/rssa.12423 PMID: 30828138
65. Jones K, Burns A. Unit Costs of Health and Social Care 2021. Personal Social Services Research Unit,
University of Kent, Canterbury; 2021. Available: https://www.pssru.ac.uk/project-pages/unit-costs/unit-
costs-2020/
66. Parkinson S, Eatough V, Holmes J, Stapley E, Midgley N. Framework analysis: a worked example of a
study exploring young people’s experiences of depression. Qual Res Psychol. 2016; 13: 109–129.
https://doi.org/10.1080/14780887.2015.1119228
PLOS ONE
Emotion regulation in children (ERiC): A protocol for mentalization based treatment for school-age children
PLOS ONE | https://doi.org/10.1371/journal.pone.0289503 August 17, 2023 22 / 23
67. Nu
´ñez L, Midgley N, Capella C, Alamo N, Mortimer R, Krause M. The therapeutic relationship in child
psychotherapy: integrating the perspectives of children, parents and therapists. Psychotherapy
Research. 2021; 31: 988–1000. https://doi.org/10.1080/10503307.2021.1876946 PMID: 33509052
68. Wolpert M. THRIVE Framework for system change. London, UK: CAMHS Press; 2019.
69. Fonagy P, Cottrell D, Phillips J, Bevington D, Glaser D, Allison E. What works for whom? A critical
review of treatments for children and adolescents. 2nd ed. New York and London: The Guilford Press;
2015.
70. Haro JM, Ayuso-Mateos JL, Bitter I, Demotes-Mainard J, Leboyer M, Lewis SW,et al. ROAMER: road-
map for mental health research in Europe. Int J Methods Psychiatr Res. 2014; 23: 1–14. https://doi.org/
10.1002/mpr.1406 PMID: 24375532
71. Pilling S, Fonagy P, Allison E, Barnett P, Campbell C, Constantinou M, et al. Long-term outcomes of
psychological interventions on children and young people’s mental health: A systematic review and
meta-analysis. PLoS One. 2020; 15: e0236525. https://doi.org/10.1371/journal.pone.0236525 PMID:
33196654
72. Shahsavari H, Matourypour P, Ghiyasvandian S, Nejad MG. Medical Research Council framework for
development and evaluation of complex interventions: A comprehensive guidance. J Educ Health Pro-
mot. 2020; 9: 88. https://doi.org/10.4103/jehp.jehp_649_19 PMID: 32509896
73. Morrison Gutman L, Joshi H, Parsonage M, Schoon I. Children of the new century: mental health find-
ings from the Millenium Cohort Study. London, UK: Centre for Mental Health; 2015.
74. O’Shea N. Covid-19 and the nation’s mental health Forecasting needs and risks in the UK: May 2021.
Centre for Mental Health. 2021. Available: https://www.centreformentalhealth.org.uk/sites/default/files/
publication/download/CentreforMentalHealth_COVID_MH_Forecasting4_May21.pdf
PLOS ONE
Emotion regulation in children (ERiC): A protocol for mentalization based treatment for school-age children
PLOS ONE | https://doi.org/10.1371/journal.pone.0289503 August 17, 2023 23 / 23
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