
Tim KaiserFreie Universität Berlin | FUB · Department of Education and Psychology
Tim Kaiser
PhD (Dr. rer. nat.)
About
74
Publications
46,657
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Introduction
I'm a postdoctoral researcher at the psychological methods and evaluation department of the Freie Universität Berlin, Germany. My current main research interests are related to causal inference, especially its development and application to psychotherapy research.
Additional affiliations
October 2016 - September 2019
Position
- Senior Researcher
Description
- Conducting psychotherapy research studies. Maintenance and development of software used for psychotherapy research, treatment planning and psychotherapy process monitoring. Supervision of Master’s theses. Teaching in undergraduate and graduate level courses. Dynamic modeling of stress, emotions and eating behavior. Development of a mobile just in-time adaptive intervention algorithm for patients with eating disorders.
October 2019 - February 2023
October 2016 - January 2019
Education
October 2016 - January 2019
Publications
Publications (74)
Psychotherapy outcome research mainly focuses on scale-level changes and constructs that were developed using cross-sectional statistical analysis, possibly concealing important findings on the level of single items, and limiting the clinical utility of outcome scales. Our goal was to explore changes in symptoms, interpersonal problems, and level o...
Objective: Due to the lack of randomization, pre–post routine outcome data precludes causal conclusions. We propose the “synthetic waiting list” (SWL) control group to overcome this limitation.
Method: First, a step-by-step introduction illustrates this novel approach. Then, this approach is demonstrated using an empirical example with data from an...
Public Health Significance Statement
In recent years, studies with high methodological quality have pointed out that the efficacy of psychotherapy in the treatment of depression is less satisfactory than previous research suggested. To optimize psychotherapy for non-responders, the paradigm of personalized therapy is coming into the research focus....
Background: Comorbidities in mental disorders are often understood by assuming a common cause. The network theory of mental disorders offers an alternative to this assumption by understanding comorbidities as mutually reinforced problems. In this study, we used network analysis to examine bridge symptoms between anxiety and depression in a large sa...
Background: Divergent outcomes of treatment for depression occur regularly, but often go undetected by clinical judgment alone. To date, no comprehensive studies are available on what the detection rate of divergent outcomes is in routine care.
Method: We analyzed a large (N = 20,882) database of clinician-rated and patient-reported outcomes from...
German version of the Multidimensional Emotional Disorder Inventory including scoring instructions.
The empirically proven high prevalence and comorbidity of emotional disorders underscore the need for transdiagnostic measures in routine clinical practice and psychotherapy research. The Multidimensional Emotional Disorder Inventory (MEDI) is a brief, transdiagnostic measure assessing nine dimensions of emotional disorders. The aim of this study w...
Background: Suicidal ideation represents a major concern in clinical practice. Yet, little is known about the effects of routine psychotherapy on the amelioration of suicidal ideation. Therefore, the aim of the current study is to assess mental disorder-specific changes of suicidal ideation in a large sample of adult outpatients undergoing routine-...
Objective: psychotherapy outcome research mainly focuses on scale-level changes and constructs that were developed using cross-sectional statistical analysis, possibly concealing important findings on the level of single items, and limiting the clinical utility of outcome scales. Our goal was to explore changes in symptoms, interpersonal problems,...
This is the first study to empirically determine the potential for data-driven personalization in the context of chronic primary pain (CPP). Effect sizes of psychological treatments for individuals with CPP are small to moderate on average. Aiming for better treatment outcomes for the individual patient, the call to personalize CPP treatment increa...
Importance
While the effects of internet- and mobile-based interventions (IMIs) for depression have been extensively studied, no systematic evidence is available regarding the heterogeneity of treatment effects (HTEs), indicating to what extent patient-by-treatment interactions exist and personalized treatment models might be necessary.
Objective...
Background
Suicidal ideation is a major concern in clinical practice. Yet, little is known about prevalence rates of suicidal ideation in patients undergoing outpatient psychotherapeutic treatment. Therefore, the aim of the current study is to assess the prevalence of suicidal ideation in a large sample of psychotherapy outpatients in Germany. The...
Link to the online R tutorial webpage: rct-tutorial.mharrer.dev.
Background
Considered one of the highest levels of evidence, results of randomized controlled trials (RCTs) remain an essential building block in mental health research. They are frequently used to confirm that an intervention “works” and to guide treatment decisions. Given their importance in the field, it is concerning that the quality of many RC...
Background
As psychotherapy involves at least two individuals, it is essential to include the interaction perspective research. During interaction, synchrony, i.e., the occurrence of simultaneous responses, can be observed at the physiological, neural, and behavioral level. Physiological responses include heart rate and electrodermal activity; neur...
Das Ziel des Artikels ist es, die Mythen von traumafokussierter Psychotherapie näher zu beleuchten, die im Zusammenhang mit der mangelnden Implementierung evidenzbasierter Verfahren zur Behandlung der Posttraumatischen Belastungsstörung (PTBS) stehen. Dazu werden im erstenTeil ausgewählte aktuelle Befunde der evidenzbasierten Psychotherapien zur Tr...
Das Ziel des Artikels ist es, die Mythen von traumafokussierter Psychotherapie näher zu beleuchten, die im Zusammenhang mit der mangelnden Implementierung evidenzbasierter Verfahren zur Behandlung der Posttraumatischen Belastungsstörung (PTBS) stehen. Dazu werden im erstenTeil ausgewählte aktuelle Befunde der evidenzbasierten Psychotherapien zur Tr...
More than 18 years ago, Molenaar (2004) published his manifesto on psychology as an idiographic science. In this issue, Schemer et al. (2022) report the results of a Delphi survey on three important methodological contributions that could accelerate the uptake of idiographic research in clinical psychology: ambulatory assessment, network analysis a...
Objective:
Psychotherapy is the first-line treatment for borderline personality disorder (BPD) in evidence-based care. The effects are, on average, medium; however, nonresponse rates point to differential treatment effects. Personalized treatment selection has the potential to improve outcomes, but they depend on the heterogeneity of treatment eff...
In recent decades, randomized-controlled trials (RCTs) have established a broad evidence base of psychotherapy with moderate-to-large effects for various mental disorders. In addition to determining the efficacy of psychotherapy, studies examining its effectiveness under everyday conditions historically paved the way for developing a practice-orien...
This article provides details on the development of a statistical learning algorithm developed for constructing personalized treatment plans for psychotherapy. The algorithm takes data collected via Ecological Momentary Assessment (EMA) as an input. From this, it constructs an idiographic disorder model that reflects the latent dimensions of this p...
Several evidence-based treatments for posttraumatic stress disorder (PTSD) are recommended by international guidelines (e.g., APA, NICE). While their average effects are in general high, non-response rates indicate differential treatment effects. Here, we used a large database of RCTs on psychotherapy for PTSD to determine a reliable estimate of th...
BACKGROUND
Prevention of binge eating through just-in-time mobile interventions requires prediction of high-risk times, e.g., by using affective states and associated contextual factors. Yet, these factors and states are highly idiosyncratic, and thus prediction models that are based on averages across individuals often fail.
OBJECTIVE
We thus dev...
Background:
Prevention of binge eating through just-in-time mobile interventions requires the prediction of respective high-risk times, for example, through preceding affective states or associated contexts. However, these factors and states are highly idiographic; thus, prediction models based on averages across individuals often fail.
Objective...
Lately, the use of patient-reported outcome measures (PROM) to adapt and improve ongoing psychotherapeutic treatments has become more widespread. Their main purpose is to support data-informed, collaborative treatment decisions which include the patient's point of view on their progress. In case of nonresponse or deterioration, these systems are ab...
Eine Leitlinie soll Fachpersonen, Betroffenen und der gesamten Bevölkerung evidenzbasierte Empfehlungen auf Basis des aktuellen wissenschaftlichen Erkenntnisstands zu Diagnostik- und Behandlungsmöglichkeiten geben. Der 3. Entwurf zur Nationalen Versorgungsleitlinie (NVL) Depression wird aktuell zur Diskussion gestellt. Gerade die Diskussionsvorlage...
Background
Eating plays an important role in mental and physical health and is influenced by affective (e.g., emotions, stress) and appetitive (i.e., food craving, hunger) states, among others. Yet, substantial temporal variability and marked individual differences in these relationships have been reported. Exploratory data analytical approaches th...
Dysfunctional expectations are a particularly important subset of cognitions that influence the development and maintenance of various mental disorders. This study aimed to develop and validate a scale to assess dysfunctional expectations in posttraumatic stress disorder (PTSD), the “Posttraumatic Expectations Scale” (PTES). In a cross-sectional st...
Background
To slow down the spread of COVID-19, the observance of basic hygiene measures, and physical distancing is recommended. Initial findings suggest that physical distancing in particular can prevent the spread of COVID-19.
Objectives
To investigate how information to prevent the spread of infectious diseases should be presented to increase...
Importance:
Major depressive disorder (MDD) affects approximately 10% of the population globally. Approximately 20% to 30% of patients with MDD do not sufficiently respond to standard treatment. Therefore, there is a need to develop more effective treatment strategies.
Objective:
To investigate whether the efficacy of cognitive behavioral therap...
Using a large database of randomized-controlled trials on psychotherapy of depression in adults, we performed a Bayesian variance ratio meta-regression.
Several evidence-based treatments for posttraumatic stress disorder (PTSD) are recommended by international guidelines (e.g., APA, NICE). While their average effects are in general high, non-response rates indicate differential treatment effects. Here, we used a large database of RCTs on psychotherapy for PTSD to determine a reliable estimate of th...
Background: Eating plays an important role in mental and physical health and is influenced by affective (e.g., emotions, stress) and appetitive (i.e., food craving, hunger) states, among others. Yet, substantial temporal variability and marked individual differences in these relationships have been reported. Exploratory data analytical approaches t...
Food craving (FC) peaks are highly context-dependent and variable. Accurate prediction of FC might help preventing disadvantageous eating behavior. Here, we examine whether data from two weeks of Ecological Momentary Assessment (EMA) questionnaires on stress and emotions (active EMA, aEMA) alongside temporal features and smartphone sensor data (pas...
Despite effective treatment approaches within the cognitive behavioral framework general treatment effects for chronic pain are rather small to very small. Translation from efficacy trials to naturalistic settings is questionable. There is an urgent need to improve the effectiveness of well-established treatments, such as cognitive-behavior therapy...
We read the article “Clinimetric Criteria for Patient-Reported Outcome Measures” with great interest. Highlighting certain test characteristics for patient-reported outcome measures (PROMs) that seem to be neglected in the psychometric literature is a commendable endeavor. We share the authors' intention of supporting clinical practice by providing...
Background
Sample size planning (SSP) is vital for efficient studies that yield reliable outcomes. Hence, guidelines, therefore, emphasize the importance of SSP. The present study investigates the practice of SSP in current trials for depression.
Methods
Seventy-eight RCTs published between 2013 and 2017 were examined. Impact of study design (e.g....
Background: Depression is a highly prevalent mental disorder, but only a fraction of those affected receive evidence-based treatments. Recently, Internet-based interventions were introduced as an efficacious and cost-effective approach. However, even though depression is a heterogenous construct, effects of treatments have mostly been determined us...
Dysfunctional expectations are a particularly important subset of cognitions that influence the development and maintenance of various mental disorders. This study aimed to develop and validate a scale to assess dysfunctional expectations in posttraumatic stress disorder (PTSD), the “Posttraumatic Expectations Scale” (PTES). In a cross-sectional st...
Background
Many people aim to eat healthily. Yet, affluent food environments encourage consumption of energy dense and nutrient-poor foods, making it difficult to accomplish individual goals such as maintaining a healthy diet and weight. Moreover, goal-congruent eating might be influenced by affects, stress and intense food cravings and might also...
Background: Many people aim to eat healthily. Yet, affluent food environments encourage consumption of energy dense and nutrient-poor foods, making it difficult to accomplish individual goals such as maintaining a healthy diet and weight. Moreover, goal-congruent eating might be influenced by affects, stress and intense food cravings and might also...
Background
Psychotherapy is an evidence-based treatment for depression, but its average effect is modest. Thus, identifying subgroups that respond especially well to psychotherapy is an important goal. This would allow maximizing the efficacy of interventions. However, the extent of treatment effect heterogeneity (TEH) has not yet been systematical...
BACKGROUND
To slow down the spread of COVID-19, the observance of basic hygiene measures, and physical distancing is recommended. Initial findings suggest that physical distancing in particular can prevent the spread of COVID-19. Attitudes towards these measures are influenced by many factors and are likely to play an important role in their compli...
Food craving (FC) peaks are highly context-dependent and variable. Accurate prediction of FC might help preventing disadvantageous eating behavior. Here, we examine whether data from two weeks of Ecological Momentary Assessment questionnaires on stress and emotions alongside smartphone sensor data would be able to predict food cravings approximatel...
Objective: Sex differences in personality are a matter of continuing debate. In a study on the US standardization sample of Cattell’s 16PF (fifth edition), Del Giudice and colleagues (2012; PLoS ONE, 7, e29265) estimated global sex differences in personality with multigroup covariance and mean structure analysis (MG-CMSA). The study found a surpris...
Smartphone-based devices are increasingly recognized to assess disease symptoms in daily life (e.g. ecological momentary assessment, EMA). Despite this development in digital psychiatry, clinical trials are mainly based on point assessments of psychopathology. This study investigated expectable increases in statistical power by intense assessment i...
Freier Download: https://www.karger.com/Article/FullText/507820
Einleitung: Voraussetzung für die Approbation im Rahmen der neuen Psychotherapeutenausbildung ist u.a. das Bestehen einer anwendungsorientierten Parcoursprüfung. Da diese Prüfung von Lehrenden und Studierenden als Herausforderung angesehen wird, wurde eine Kurzform der Parcoursprüfung...
Background
Cognitive behavioral and psychodynamic therapy methods are in competition as far as evidence for their effectiveness is concerned. Although there have already been comparative efficacy studies, these often do not reflect the care situation in Germany. At the beginning of the year, the results of the LAC depression study were presented, w...
Sex differences in personality were found to be larger in more developed and more gender-equal societies. However, the studies that report this effect either have methodological shortcomings or do not take into account possible underlying effects of ecological variables.
Here, a large, multinational (N = 867,782) dataset of personality profiles wa...
Mit großem Interesse haben wir daher die erneute Publikation (Leuzinger-Bohleber, Hautzinger, Keller, et al., 2019) der Ergebnisse der Studie zu Langzeitbehandlungen bei chronisch depressiven Patienten (kurz: LAC-Studie) gelesen. Bislang haben die Autoren die regelmäßig veröffentlichten „Tranchen“ des sicherlich beträchtlichen Datensatzes dieses Fo...
Sex differences in personality were found to be larger in more developed and more gender-equal societies. However, the studies that report this effect either have methodological shortcomings or do not take into account possible underlying effects of ecological variables.
Here, a large, multinational (N = 867,782) dataset of personality profiles wa...
Aim: Real-time monitoring of psychotherapeutic processes was recently described as a promising, new way of tracking periods of change in ongoing treatments. This approach generates complex, multivariate datasets that have to be presented in an intuitive way for clinicians to aid their clinical decision-making. Using network modeling and new approac...
Aim: real-time monitoring of psychotherapeutic processes was recently described as a promising, new way of tracking periods of change in ongoing treatments. This approach generates complex, multivariate datasets that have to be presented in an intuitive way for clinicians to aid their clinical decision-making. Using network modeling and new approac...
While monitoring systems in psychotherapy have become more common, little is known about the attitudes that mental health practitioners have towards these systems. In an online survey among 111 Austrian psychotherapists and trainees, attitudes towards therapy monitoring were measured. A well-validated questionnaire measuring attitudes towards outco...
Background: the typical mode of assessment in studies on intersession processes (ISP) in psychotherapy is using cross-sectional or weekly measurements. Daily dynamics of intersession processes have not yet been studied.
Method: intersession process data from 22 ambulatory psychotherapy cases were collected in a naturalistic study with high tempora...
Modern technologies like smartphones, tablet computers and other Internet-enabled devices spread rapidly and reach an increasing number of people. In the field of mental health, many different approaches for supporting assessment, treatment planning, but also treatment of mental disorders have been developed. The possibilities for providing univers...
While monitoring systems in psychotherapy become more and more common, not much is known about the attitudes that mental health practitioners have towards these systems. Also, not only session-by-session monitoring systems are currently used in psychotherapy, but also systems using daily measures to capture the therapeutic process in real time. In...
While monitoring systems in psychotherapy become more and more common, not much is known about the attitudes that mental health practitioners have towards these systems. Also, not only session-by-session monitoring systems are currently used in psychotherapy, but also systems using daily measures to capture the therapeutic process in real time. In...
As non-linear time series analysis becomes more and more widespread , measures that can be applied to short time series with relatively low temporal resolution are in demand. The author introduces a complexity parameter for time series based on fluctuation and distribution of values, as well as its R implementation. This parameter is validated with...
Over the last years, psychotherapy research moved its focus to methods of diagnostics and intervention that use novel statistical methods for individualization. The goal of this project is to develop such an algorithm and validate it empirically in real-world psychotherapeutic settings.
Background:
In recent years, the assessment of mental disorders has become more and more personalized. Modern advancements such as Internet-enabled mobile phones and increased computing capacity make it possible to tap sources of information that have long been unavailable to mental health practitioners.
Objective:
Software packages that combine...
Patterns are a methodology for capturing best practices and solutions to reoccurring problems in certain fields or disciplines. Applied to automotive interaction design they can combine empirical data, industry knowledge, and experts’ experience for state-of-the-art design solutions. In this paper, we present the patterns approach and its applicati...
Car user experience patterns are a systematic way to capture best practices and solutions to reoccurring problems in automotive interaction design. Combining empirical data, industry knowledge, and experts experience, they facilitate communication between scientists and industry stakeholders. In this paper, we present a newly generated set of eight...
The present paper addresses the time-dependent analysis of intra- and intersession processes in psychotherapy. Process data for psychotherapies of 21 patients were collected for a period of nine weeks. A new method named “time-series panel analysis“ (TSPA) was used to process these data. Idiographic models for individual therapy courses were comput...
Die bisherige Psychotherpieforschung hat sich in erster Linie mit Ereignissen und Prozessen innerhalb der Therapie, im besonderen innerhalb von Therapiesitzungen, beschäftigt. Psychotherapeutische und veränderungsrelevante Prozesse finden aber auch außerhalb derselben statt. Eine Gruppe von diesen Prozessen, die zwischen den Therapiesitzungen anges...
The present paper addresses the assessment of psychotherapy patients’ representations of
therapeutic processes within and in between sessions. A theoretical concept of intrasession processes does not yet exist and was therefore elaborated. A newly constructed intrasession experience questionnaire was used, which proved good reliability. Correlation...