Matthew T Feldner

• Ph.D.
• Managing Director at Canopy Growth Corporation

Caffeine and cannabidiol (CBD) are commonly consumed by the general population, particularly among young adults; however, there is little research on the simultaneous effects of caffeine and CBD. The present study aimed to examine the simultaneous self-reported effects of caffeine and CBD in young healthy adults. Participants (N = 54) who reported...

The present study sought to determine the effects of cannabinol (CBN) alone and in combination with cannabidiol (CBD) on sleep quality. This was a double-blind, randomized, placebo-controlled study conducted between May and November 2022. Participants were randomized to receive either (a) placebo, (b) 20 mg CBN, (c) 20 mg CBN + 10 mg CBD, (d) 20 mg...

Introduction: Tetrahydrocannabivarin (THCV) is an understudied cannabinoid that appears to have effects that vary as a function of dose. No human study has evaluated the safety and nature of effects in a wide range of THCV doses. Methods: This was a two-phase, dose-ranging, placebo-controlled trial of the Δ8 isomer of oral THCV in healthy adults....

Introduction: Despite efforts to curb nicotine use, 8.1 million adults in the United States use e-cigarettes. Notably, the majority of nicotine-containing e-cigarette users report wanting to quit in the near future, yet there is a dearth of research surrounding intervention efforts. Cannabidiol (CBD) has potential to facilitate e-cigarette quit att...

Background: Recent studies recommend medicinal cannabis (MC) as a potential treatment for chronic pain (CP) when conventional therapies are not successful; however, data from Australia is limited. This real-world evidence study explored how the introduction of MC related to concomitant medication use over time. Long-term safety also was examined....

Objective A single administration of cannabidiol (CBD) can reduce anxiety during social anxiety inductions. No study, however, has evaluated the impact of CBD on fear responding among humans. Method A double-blind, randomized, placebo-controlled trial was undertaken to address this gap in the literature. Specifically, the current study tested a si...

Background and Objective Idiographic script-driven imagery is core to both research and treatment related to posttraumatic stress disorder (PTSD), including among individuals with a history of sexual assault. However, there may be benefit in having alternatives to such idiographic techniques. The current study therefore examined multimodal respondi...

Background and objectives Avoidance and sleep have been identified as mechanisms involved in the development and maintenance of many mental health disorders. However, there has been little research into the relation between sleep and avoidance. Methods To address this, a randomized controlled experiment using behavioral and self-report measures of...

Background Use of medical cannabis is increasing among older adults. However, few investigations have examined cannabis use in this population. Methods We assessed the authorization patterns, safety, and effects of medical cannabis in a sub-analysis of 201 older adults (aged ≥ 65 years) who completed a 3-month follow-up during this observational s...

Delta-8-tetrahydrocannabinol (Δ8-THC) has emerged as a new retail cannabinoid product in the U.S. This study queried Δ8-THC users about product use characteristics and self-reported drug effects. Participants were recruited via a large online crowdsourcing platform (Amazon Mechanical Turk). Adults (N = 252) with past year Δ8-THC use (35% with at le...

Introduction Approximately 36% of adolescents report sleep problems (Crowley et al., 2018). Understanding the relation between sleep and emotional experience is crucial in understanding the high incidence of mental health concerns during adolescence. The current study sought to expand understanding in the area by testing the hypothesis that baselin...

Empirical evidence continues to accumulate suggesting cannabidiol (CBD) may have potential as an anxiolytic. Yet, research in the area is insufficient to support strong inferences. Accordingly, there is a need for additional empirical investigation. Research on the effects of CBD and anxiety requires a working knowledge of both. Understanding of co...

Objective: Telehealth is increasingly recognized as an avenue for enhancing psychologists' capacities to meet the mental health needs of a diverse and underserved (due to barriers e.g., distance, transportation) public. The present study sought to inform training in telepsychology (i.e., telehealth delivery of psychological services) by using both...

BACKGROUND : Small hippocampal volume is a prevalent neurostructural abnormality in posttraumatic stress disorder (PTSD). However, whether the hippocampal atrophy is the cause of disease symptoms or a pre-existing risk factor and whether it is a reversible alteration or a permanent trait are unclear. The trait- or state-dependent alteration could a...

The intensity of peritraumatic emotions occurring at the time of, and in the hours or days immediately following, a traumatic event prospectively predicts posttraumatic stress symptom severity. However, less is known about how the perception of one’s ability to tolerate distressing emotions affects the relation between peritraumatic emotions and po...

Introduction A common form of emotion regulation is avoidance, in which attention toward negative stimuli results in avoiding (Elliot, 2006). Dysfunctional avoidance is linked to negative outcomes in various forms of psychopathology (Kashdan, Barrios, Forsyth, & Steger, 2006). Sleep challenges have been identified as a mechanism in numerous mental...

Individual differences related to disgust have been implicated in a host of psychiatric disorders, including obsessive–compulsive disorder (OCD). Theory suggests that individual differences in disgust propensity and, perhaps, sensitivity, make individuals more prone to experience disgust when confronted with potential contaminants, which then motiv...

While fear and anger have been extensively studied as emotions involved in posttraumatic stress disorder, shame is an important emotion to examine in those who have experienced a traumatic event, as it is often associated with treatment avoidance and treatment resistance. Compared to guilt, which is associated with having participated in something...

Objective: Adult research supports the efficacy of targeting the malleable risk factor of anxiety sensitivity (AS) in preventing anxiety and related psychopathology. However, very little work has evaluated the impact of AS reduction among youth, which is unfortunate given adolescence is a "core risk" period in terms of disorder onset. Method: Th...

Self-regulation of brain activation with real-time functional magnetic resonance imaging neurofeedback (rtfMRI-nf) is emerging as a promising treatment for psychiatric disorders. The association between the regulation and symptom reduction, however, has not been consistent, and the mechanisms underlying the symptom reduction remain poorly understoo...

Objective: Adult research employing script-driven imagery procedures has shown the method to be a valuable tool for studying the nature, correlates, and consequences of trauma and posttraumatic stress symptoms (PTSS). The purpose of the current study was to examine the validity of a trauma-focused script-driven imagery procedure among youth. Meth...

Introduction Studies suggest adolescent cigarette smoking is associated with sleep difficulties (Pasch, Latimer, Cance, Moe, & Lytle, 2012), yet little work has examined smoking and sleep onset latency (SOL). Adult research suggests smoking prospectively relates to SOL (Cohrs et al., 2014). A meta-analysis found mixed evidence for adolescents (Bart...

Experimental and clinical studies have demonstrated an association between posttraumatic stress symptoms (PTSS) and anger. Expanding upon past research, the current study examined the interactive associations among PTSS, distress tolerance (DT), and anger responding among a sample of 95 trauma-exposed adults. This study used a personalized script-d...

Objective A suicide attempt is an established risk factor for subsequent suicide attempts and suicide. Nonetheless, the prediction of future suicidal behavior is poor. The lethality of previous suicidal behavior may be informative to better understand future suicide risk among patients hospitalized for suicidal thoughts and behavior. The current st...

A large body of work links parental sick role reinforcement behavior to adolescent panic vulnerability. To date, however, little work has examined the role of the adolescent in this process. The current study addressed this gap in the literature, using a novel method to experimentally test the impact of adolescent anxiety during a straw-breathing t...

Research suggests important associations between emotion regulation difficulties and posttraumatic stress disorder (PTSD) symptomology, with prospective studies indicating that emotion regulation difficulties may lead to increased PTSD symptoms. Peritraumatic dissociation is considered an important and consistent predictor of PTSD symptoms. The pre...

Self-regulation of brain activation using real-time functional magnetic resonance imaging neurofeedback (rtfMRI-nf) is an emerging approach for treating mood and anxiety disorders. The effect of neurofeedback training on resting-state functional connectivity warrants investigation as changes in spontaneous brain activation could reflect the associa...

Posttraumatic stress disorder (PTSD) is a trauma- and stressor-related disorder that may emerge following a traumatic event. Neuroimaging studies have shown evidence of functional abnormality in many brain regions and systems affected by PTSD. Exaggerated threat detection associated with abnormalities in the salience network, as well as abnormaliti...

Objective. Parents can facilitate offspring anxiety in response to bodily arousal via “sick role reinforcement,” a process that may be important during adolescence. Although a sizeable body of work has examined the role of parent behavior in this process, no study to date has examined child-driven effects on parental sick role reinforcement. Furthe...

Posttraumatic stress disorder (PTSD) is a chronic and disabling neuropsychiatric disorder characterized by insufficient top-down modulation of the amygdala activity by the prefrontal cortex. Real-time fMRI neurofeedback (rtfMRI-nf) is an emerging method with potential for modifying the amygdala-prefrontal interactions. We report the first controlle...

Posttraumatic stress disorder (PTSD) is a chronic and disabling neuropsychiatric disorder characterized by insufficient top-down modulation of the amygdala activity by the prefrontal cortex. Real-time fMRI neurofeedback (rtfMRI-nf) is an emerging method with potential for modifying the amygdala-prefrontal interactions. We report the first controlle...

Altered resting-state functional connectivity in posttraumatic stress disorder (PTSD) suggests neuropathology of the disorder. While seed-based fMRI connectivity analysis is often used for the studies, such analysis requires defining a seed location a priori, which restricts search scope and could bias findings toward presupposed areas. Recently, a...

Suicide risk is highly prevalent among individuals with posttraumatic stress disorder (PTSD). Self-disgust, defined as disgust directed internally and comprised of disgust with oneself (disgusting self) and with one’s behaviors (disgusting ways), may impact this increased risk. The present study examined self-disgust as a putative mechanism linking...

Marijuana use and trauma have independently been associated with an increased risk for violence among adolescents; however, research has not examined potential associations between marijuana use and violence among trauma-exposed adolescents. Therefore, we examined data from two groups of adolescents: (a) those reporting exposure to a criterion A-de...

Affective lability, or the instability of emotional states, is associated with heightened levels of trauma-related emotional responding and posttraumatic stress disorder (PTSD) symptoms. However, the impact of affective lability, specifically on habituation to idiographic trauma cues, has yet to be examined among trauma-exposed individuals. The cur...

Cigarette smoking during adolescence is linked to a number of sleep disturbances and has been consistently linked to sleep onset latency among adults. However, little research has examined factors that may influence the relation between cigarette smoking level and sleep onset latency among adolescents. One factor that may be particularly important...

Objective: Empirical examinations of the relation between posttraumatic stress disorder (PTSD) and objective measures of symptom over-reporting may be useful for identification of mechanisms of this previously observed relation. The present study examined the moderating effect of alexithymia, defined as a deficit in the ability to identify and des...

Evidence suggests that smoking to cope among adolescents is associated with a number of problematic outcomes (e.g., greater smoking frequency, higher rates of dependence). It is thus imperative to better understand factors that may increase the likelihood of smoking to cope among adolescents. Research suggests anxiety sensitivity (AS) is associated...

Objective: Social functioning is negatively impacted by the presence of PTSD, while increasing risk of suicidal behavior among individuals with PTSD. However, little research has examined the specific role of social functioning in the association between PTSD and suicidal behavior. Method: Parallel multiple indirect effects analyses were perform...

A relatively limited research base suggests parenting practices, particularly those characterized by overcontrol, are linked to elevated risk for offspring experiencing panic symptoms. However, extant research conducted in this domain is based on adult retrospective report, and the relation between parental psychological control (parenting characte...

Background: Real-time fMRI neurofeedback (rtfMRI-nf) is a promising approach for studies and treatment of major depressive disorder (MDD). EEG performed simultaneously with rtfMRI-nf procedure allows independent evaluation of rtfMRI-nf effects. Frontal EEG asymmetry in the alpha band is a widely used measure of emotion and motivation that shows pro...

The current review provides a detailed analysis of the burgeoning literature examining the role of disgust in understanding posttraumatic stress symptomatology. Research in this area generally converges to suggest (1) posttraumatic stress is associated with the experience of elevated disgust, (2) individual differences in disgust vulnerabilities ma...

Objective: Nonmedical prescription drug use, defined as using the drug without a prescription or in ways for which it is not prescribed, and traumatic event exposure are highly prevalent among college students. Despite evidence that posttraumatic stress symptoms could place college students at risk for nonmedical prescription drug problems, no stu...

Studies have documented complex, bidirectional relationships between sleep and affect. Dysregulated affect, particularly affect characterized by heightened arousal, appears to be central to these linkages. However, a great deal of work is needed to advance our understanding of sleep-affect associations and the underlying mechanisms and factors affe...

Objective: Emerging evidence identifies disgust as a common and persistent reaction following sexual victimization that is linked to posttraumatic stress disorder (PTSD). Importantly, evidence suggests that compared with fear, disgust may be less responsive to repeated exposure, which may have implications for the treatment of PTSD. The current st...

The current study examined relations among individual facets of emotional awareness and mindfulness, and associations between these facets and quality of life. Facets of emotional awareness include: Attention to emotions, Understanding of type, Understanding of source, Negative differentiation, and Positive differentiation. Facets of mindfulness in...

Clinical science, as discussed here, refers to a career path involving the science-centered application of clinical psychology services. We discuss careers in clinical science primarily as those in clinical psychology with an emphasis on clinical psychology research. What follows is a list of critical questions to which students will need answers i...

Panic disorder ( PD ) has been well studied over the last four decades. This entry provides an overview of the presenting features and clinical correlates of PD , and it reviews the primary psychobiological risk factors associated with this condition. Following a discussion of prominent existing models of etiology and maintenance, a review of asses...

Sleep and Affect provides a one-stop source for state-of-the-art theory, methods, and clinical science regarding the interrelations between sleep and affect. Supported by a strong empirical backbone focused on contemporary research outlining links between sleep and affect, this book offers a guide to (1) state-of-the art research methods for studyi...

Sleep and Affect: Assessment, Theory, and Clinical Implications synthesizes affective neuroscience research as it relates to sleep psychology and medicine. Evidence is provided that normal sleep plays an emotional regulatory role in healthy humans. The book investigates interactions of sleep with both negative and positive emotions, along with thei...

The Facial Action Coding System (Ekman & Friesen) has shown promise as a behavioral measure of emotional experience. The current study examined the degree of (de)synchrony between self-reported and facial expressions of fear, disgust, and sadness in response to a traumatic event–relevant film among individuals who had experienced a traumatic motor...

Contamination concerns have been linked to increased posttraumatic stress symptoms. The present study offered a preliminary test of the roles of domain-specific contamination aversions in posttraumatic stress. Fifty women with a history of sexual or physical assault were recruited from the community and assessed for posttraumatic stress symptom sev...

Research suggests that moral disgust, shame, and guilt are present in posttraumatic psychopathology. However, it is unclear that these emotional states are responsive to empirically supported interventions for posttraumatic stress symptoms (PTSS). This study explored the relations among moral disgust, shame, guilt, and PTSS, and examined comprehens...

Objective Escape and avoidance behaviors play a prominent role in the maintenance and possibly development of panic disorder, yet the literature regarding the etiology of these emotion-regulation strategies is relatively underdeveloped. The current study experimentally tests hypotheses that parental modeling of escape during a well-established, pan...

Caffeine is the most widely consumed psychoactive substance in the world, however there is no available, comprehensive measure with which to formally assess individuals’ motivations for use. In the current study, we sought to develop and validate a measure of caffeine motives (the Caffeine Motives Questionnaire; CMQ). An exploratory factor analysis...

Objectives: Research has linked parental post-traumatic stress disorder (PTSD) and parental smoking to a wide array of psychological and physical health concerns among offspring. Furthermore, the combination of parental anxiety psychopathology generally, along with smoking, has been linked to elevated adolescent panic symptomatology. However, no re...

Careers in psychological clinical science (hereafter referred to as “clinical science”) involve an integration of science and clinical practice. Programs focused on clinical science training often are competitive, but steps can be taken to maximize the competitiveness of an application to these programs. These include obtaining research experience,...

Risk for suicide among adolescents remains a serious public health concern. Despite the relevance of individual differences in affective experience to clinically relevant problems generally, and risk for suicide more specifically, relatively little work has evaluated affect intensity in relation to adolescent risk for suicide. To address this notab...

Individuals with posttraumatic stress disorder (PTSD) are at an elevated risk for experiencing suicidal thoughts and actions. However, a relative dearth of research has examined factors that may impact this relation, such as common co-occurring disorders. Utilizing the National Comorbidity Survey-Replication data, the current study examined compari...

People with either posttraumatic stress disorder (PTSD) or alcohol dependence (AD) are apt to report problems in their social networks, including low perceived support and elevated conflict. However, little research has examined social networks among people with comorbid PTSD/AD despite evidence suggesting these two conditions commonly co-occur and...

Millions of individuals with posttraumatic stress disorder (PTSD) are parents. A burgeoning literature suggests that offspring of parents with this condition may be at increased risk for psychological problems. The current paper provides an integrative and comprehensive review of the diverse research literature examining the sequelae of parental po...

The present study examined an integrated treatment for comorbid posttraumatic stress disorder (PTSD) and smoking entitled "Smoke-Free to Overcome PTSD: An Integrated Treatment" (STOP IT program). A nonconcurrent multiple-baseline design was used with six community-recruited adult smokers with PTSD to investigate both patient acceptance of the treat...

Disgust sensitivity and feelings of mental contamination have both been independently linked to posttraumatic stress symptoms following sexual assault. Theory suggests that feelings of mental contamination may arise, at least in part, as a result of interpreting feelings of disgust experienced in relation to sexual assault to mean that one has been...

Cognitive-behavioral therapy (CBT) is efficacious and effective in the treatment of anxiety disorders. However, few guidelines exist on how to efficiently provide CBT when comorbidity is present. Given that anxiety disorders may share underlying mechanisms of maintenance, targeting such mechanisms may be fruitful when working with individuals who s...

Independent lines of evidence have linked posttraumatic stress symptomatology to both peritraumatic disgust (i.e., disgust experienced during a traumatic event) and posttraumatic disgust reactivity in response to traumatic event cues among individuals exposed to traumatic events. Much of this work suggests disgust, defined as a rejection/revulsion...

This chapter aims to provide a background in anxiety disorder/substance use disorder (SUD) comorbidity and its treatment, with an in-depth focus on social anxiety disorder (SAD) and posttraumatic stress disorder (PTSD). The chapter covers relevant comorbidity models and describes the complexities of these comorbid conditions, followed by a section...

Disgust and mental contamination (or feelings of dirtiness and urges to wash in the absence of a physical contaminant) are increasingly being linked to traumatic event exposure and posttraumatic stress (PTS) symptomatology. Evidence suggests disgust and mental contamination are particularly relevant to sexual assault experiences; however, there has...

Poor sleep quality has been linked to posttraumatic stress disorder (PTSD). This study provided a test of how poor sleep quality relates to real-time assessment of anxious reactivity to idiographic traumatic event cues. Script-driven imagery (SDI) was employed to examine reactivity to traumatic event cues among 46 women (mean age = 27.54 years, SD...

Background and objectives: Both emotional reactivity to traumatic event cues and difficulties regulating emotion have been linked to posttraumatic stress symptom severity. The current study uniquely extended these two lines of research by examining the degree to which these two factors alone, and in combination, account for variability in posttrau...

Theory implicates peritraumatic fear-based interoceptive conditioning in the development of panic spectrum problems subsequent to traumatic event exposure. Relatively little empirical work has directly investigated this hypothesis. The current study tested the hypothesis that level of peritraumatic fear would predict anxious reactivity to a well-es...

Avoidance coping and symptoms of posttraumatic stress disorder (PTSD) covary. However, relatively little research has examined the bi-directional relation between these constructs among individuals in treatment for PTSD. The current longitudinal study examined the reciprocal associations between avoidance coping and PTSD symptom severity during and...

Emerging evidence has documented comorbidity between posttraumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD) among individuals with a history of traumatic events. There is growing recognition of the importance of disgust in each of these conditions independently. No study, however, has examined the potential role of disgust in...

Anxiety along with anxiety-related risk factors is receiving increased attention in regard to its role in elevated suicidality. One such risk factor, anxiety sensitivity (AS), refers to a fear of anxiety-related symptoms. Emerging research indicates that components of AS, particularly the AS subfactor focused on cognitive arousal concerns, are sign...

Based on the personal and societal costs of long-term sleep medication use, it is important to understand factors that may play a role in use of medications to manage sleep. One such factor is fear of the consequences of anxiety-related sensations, or anxiety sensitivity. Participants in the current study included 205 unscreened adults who complete...

Contemporary comorbidity theory postulates that people suffering from posttraumatic stress symptoms may use substances to cope with negative affect generally and posttraumatic stress symptoms specifically. The present study involves the examination of the unique relation between past two-week posttraumatic stress symptom frequency and motives for m...

The current study uniquely extended research that has linked traumatic event exposure to panic-spectrum problems among adolescents. It was hypothesized that among 127 adolescents (age range: 10 to 17 years; M = 14.63, SD = 2.24), those who endorsed a history of traumatic event exposure would evidence significantly greater anxious and fearful reacti...

An emerging pattern of results from panic-relevant biological challenge studies suggests women respond with greater subjective anxiety than men, but only to relatively abrupt and intense challenge procedures. The current investigation examined the relation between biological sex and self-reported anxious reactivity following biological challenges o...

Models of traumatic event-related emotional reactivity have primarily focused on fear. Emerging research points to the importance of advancing our currently limited understanding of how anger and disgust relate to certain types of traumatic experiences, such as interpersonal violence (IPV). The current study compared anger, disgust, and anxiety in...

Posttraumatic stress symptoms and self-reported sleep problems reliably covary. The current study investigated how posttraumatic stress symptom clusters (i.e., hyperarousal, avoidance, and reexperiencing) relate to trouble initiating and maintaining sleep and nightmares. Participants included traumatic event-exposed respondents from the NCS-R. Resu...

Posttraumatic stress disorder (PTSD) and elevated levels of substance use (SU) regularly co-occur and are increasingly viewed as functionally related. While PTSD and SU may be comorbid for a variety of reasons, central theoretical work posits that individuals with PTSD use substances to regulate affective experiences. In particular, two theories of...

More than 70 million people in the United States experience primary insomnia (PI) at some point in their life, resulting in an estimated $65 billion in health care costs and lost productivity. PI is therefore one of the most common health care problems in the United States. To mollify the negative effects of PI, scholars have sought to evaluate and...

Data from the National Comorbidity Survey-Replication were used to evaluate links between parental posttraumatic stress disorder (PTSD) and elevated (1) offspring internalizing problems and (2) parental physical aggression toward children. We extended prior tests via the use of an independent nationally representative sample and by examining specif...

Poor sleep quality commonly co-occurs with anxiety among youth. However, little research has examined linkages between sleep quality and factors thought to underlie panic vulnerability. This study tested the association between self-reported sleep quality and anxiety and fear reported during panic-relevant abrupt increases in bodily arousal elicite...

Evidence documents elevated rates of various types of drug use among people with posttraumatic stress disorder (PTSD). However, relatively little research has specifically examined crystal methamphetamine (CM) use among individuals with PTSD. The present study examined the relation between PTSD diagnostic status, PTSD symptom severity within sympto...

The present study empirically tested the theory-based hypothesis that greater sleep problems and post-traumatic stress disorder (PTSD) symptom severity would both individually and multiplicatively predict higher levels of coping-motivated marijuana use. Twenty (15 women) adults (M age = 34.00 years, SD = 11.96) who had PTSD and were currently using...

The construct of emotion regulation has been increasingly investigated in the last decade, and this work has important implications for advancing anxiety disorder theory. This paper reviews research demonstrating that: 1) emotion (i.e., fear and anxiety) and emotion regulation are distinct, non-redundant, constructs that can be differentiated at th...