Key influences on university students' physical activity: a systematic review using the Theoretical Domains Framework and the COM-B model of human behaviour.

BACKGROUND: Physical activity is important for all aspects of health, yet most university students are not active enough to reap these benefits. Understanding the factors that influence physical activity in the context of behaviour change theory is valuable to inform the development of effective evidence-based interventions to increase university students' physical activity. The current systematic review a) identified barriers and facilitators to university students' physical activity, b) mapped these factors to the Theoretical Domains Framework (TDF) and COM-B model, and c) ranked the relative importance of TDF domains. METHODS: Data synthesis included qualitative, quantitative, and mixed-methods research published between 01.01.2010-15.03.2023. Four databases (MEDLINE, PsycINFO, SPORTDiscus, and Scopus) were searched to identify publications on the barriers/facilitators to university students' physical activity. Data regarding study design and key findings (i.e., participant quotes, qualitative theme descriptions, and survey results) were extracted. Framework analysis was used to code barriers/facilitators to the TDF and COM-B model. Within each TDF domain, thematic analysis was used to group similar barriers/facilitators into descriptive theme labels. TDF domains were ranked by relative importance based on frequency, elaboration, and evidence of mixed barriers/facilitators. RESULTS: Thirty-nine studies involving 17,771 participants met the inclusion criteria. Fifty-six barriers and facilitators mapping to twelve TDF domains and the COM-B model were identified as relevant to students' physical activity. Three TDF domains, environmental context and resources (e.g., time constraints), social influences (e.g., exercising with others), and goals (e.g., prioritisation of physical activity) were judged to be of greatest relative importance (identified in > 50% of studies). TDF domains of lower relative importance were intentions, reinforcement, emotion, beliefs about consequences, knowledge, physical skills, beliefs about capabilities, cognitive and interpersonal skills, social/professional role and identity, and behavioural regulation. No barriers/facilitators relating to the TDF domains of memory, attention and decision process, or optimism were identified. CONCLUSIONS: The current findings provide a foundation to enhance the development of theory and evidence informed interventions to support university students' engagement in physical activity. Interventions that include a focus on the TDF domains 'environmental context and resources,' 'social influences,' and 'goals,' hold particular promise for promoting active student lifestyles. TRIAL REGISTRATION: Prospero ID-CRD42021242170.

A Novel, Expert-Endorsed, Neurocognitive Digital Assessment Tool for Addictive Disorders: Development and Validation Study.

BACKGROUND: Many people with harmful addictive behaviors may not meet formal diagnostic thresholds for a disorder. A dimensional approach, by contrast, including clinical and community samples, is potentially key to early detection, prevention, and intervention. Importantly, while neurocognitive dysfunction underpins addictive behaviors, established assessment tools for neurocognitive assessment are lengthy and unengaging, difficult to administer at scale, and not suited to clinical or community needs. The BrainPark Assessment of Cognition (BrainPAC) Project sought to develop and validate an engaging and user-friendly digital assessment tool purpose-built to comprehensively assess the main consensus-driven constructs underpinning addictive behaviors. OBJECTIVE: The purpose of this study was to psychometrically validate a gamified battery of consensus-based neurocognitive tasks against standard laboratory paradigms, ascertain test-retest reliability, and determine their sensitivity to addictive behaviors (eg, alcohol use) and other risk factors (eg, trait impulsivity). METHODS: Gold standard laboratory paradigms were selected to measure key neurocognitive constructs (Balloon Analogue Risk Task [BART], Stop Signal Task [SST], Delay Discounting Task [DDT], Value-Modulated Attentional Capture [VMAC] Task, and Sequential Decision-Making Task [SDT]), as endorsed by an international panel of addiction experts; namely, response selection and inhibition, reward valuation, action selection, reward learning, expectancy and reward prediction error, habit, and compulsivity. Working with game developers, BrainPAC tasks were developed and validated in 3 successive cohorts (total N=600) and a separate test-retest cohort (N=50) via Mechanical Turk using a cross-sectional design. RESULTS: BrainPAC tasks were significantly correlated with the original laboratory paradigms on most metrics (r=0.18-0.63, P<.05). With the exception of the DDT k function and VMAC total points, all other task metrics across the 5 tasks did not differ between the gamified and nongamified versions (P>.05). Out of 5 tasks, 4 demonstrated adequate to excellent test-retest reliability (intraclass correlation coefficient 0.72-0.91, P<.001; except SDT). Gamified metrics were significantly associated with addictive behaviors on behavioral inventories, though largely independent of trait-based scales known to predict addiction risk. CONCLUSIONS: A purpose-built battery of digitally gamified tasks is sufficiently valid for the scalable assessment of key neurocognitive processes underpinning addictive behaviors. This validation provides evidence that a novel approach, purported to enhance task engagement, in the assessment of addiction-related neurocognition is feasible and empirically defensible. These findings have significant implications for risk detection and the successful deployment of next-generation assessment tools for substance use or misuse and other mental disorders characterized by neurocognitive anomalies related to motivation and self-regulation. Future development and validation of the BrainPAC tool should consider further enhancing convergence with established measures as well as collecting population-representative data to use clinically as normative comparisons.

Personal and relational changes following deep brain stimulation for treatment-resistant depression: A prospective qualitative study with patients and caregivers.

OBJECTIVE: Deep brain stimulation (DBS) and whether it alters patient personality is a much-debated topic within academic literature, yet rarely explored with those directly involved. This study qualitatively examined how DBS for treatment-resistant depression impacts patient personality, self-concept, and relationships from the perspectives of both patients and caregivers. METHODS: A prospective qualitative design was used. Eleven participants were included (six patients, five caregivers). Patients were enrolled in a clinical trial of DBS of the bed nucleus of the stria terminalis. Semi-structured interviews were conducted with participants before DBS-implantation and 9-months after stimulation-initiation. The 21 interviews were thematically analysed. RESULTS: Three primary themes were identified: (a) impact of mental illness and treatment on self-concept; (b) device acceptability and usability, and (c) relationships and connection. Severe refractory depression had profoundly impacted who patients were, how they viewed themselves, and the quality and functioning of their relationships. Patients who benefited from DBS felt reconnected with their premorbid self, yet still far from their ideal self. While reductions in depression were broadly beneficial for relationships, the process of adjusting relationship dynamics created new challenges. All patients reported recharging difficulties and challenges adapting to the device. CONCLUSIONS: Therapeutic response to DBS is a gradual and complex process that involves an evolving self-concept, adjusting relationship dynamics, and growing connection between body and device. This is the first study to provide in-depth insight into the lived experience of DBS for treatment-resistant depression. Patient and caregiver narrative accounts should be routinely collected to guide more person-centred DBS clinical interventions.

Using event-related potentials to characterize inhibitory control and self-monitoring across impulsive and compulsive phenotypes: a dimensional approach to OCD.

OBJECTIVE: "Subsyndromal" obsessive-compulsive disorder symptoms (OCDSs) are common and cause impaired psychosocial functioning. OCDSs are better captured by dimensional models of psychopathology, as opposed to categorical diagnoses. However, such dimensional approaches require a deep understanding of the underlying neurocognitive drivers and impulsive and compulsive traits (ie, neurocognitive phenotypes) across symptoms. This study investigated inhibitory control and self-monitoring across impulsivity, compulsivity, and their interaction in individuals (n = 40) experiencing mild-moderate OCDSs. METHODS: EEG recording concurrent with the stop-signal task was used to elicit event-related potentials (ERPs) indexing inhibitory control (ie, N2 and P3) and self-monitoring (ie, error-related negativity and correct-related negativity (CRN): negativity following erroneous or correct responses, respectively). RESULTS: During unsuccessful stopping, individuals high in both impulsivity and compulsivity displayed enhanced N2 amplitude, indicative of conflict between the urge to respond and need to stop (F(3, 33) = 1.48, P < .05, 95% Cl [-0.01, 0.001]). Individuals high in compulsivity and low in impulsivity showed reduced P3 amplitude, consistent with impairments in monitoring failed inhibitory control (F(3, 24) = 2.033, P < .05, 95% CI [-0.002, 0.045]). Following successful stopping, high compulsivity (independent of impulsivity) was associated with lower CRN amplitude, reflecting hypo-monitoring of correct responses (F(4, 32) = 4.76, P < .05, 95% CI [0.01, 0.02]), and with greater OCDS severity (F(3, 36) = 3.32, P < .05, 95% CI [0.03, 0.19]). CONCLUSION: The current findings provide evidence for differential, ERP-indexed inhibitory control and self-monitoring profiles across impulsive and compulsive phenotypes in OCDSs.

Lifestyle risk factors for obsessive-compulsive symptoms and related phenomena: What should lifestyle interventions target?

OBJECTIVE: Understanding the impact of lifestyle on mental illness symptoms is important for informing psycho-education and developing interventions which target mental and physical comorbidities. Obsessive-compulsive and related disorders can have a significant impact on health-related quality of life and physical health. However, our understanding of the impact of lifestyle on obsessive-compulsive symptoms and broader compulsive and impulsive problematic repetitive behaviours is limited. AIMS: We investigated whether lifestyle factors predicted change in obsessive-compulsive symptoms and problematic repetitive behaviours in a general population sample over a 3-month period. METHODS: Eight hundred thirty-five participants completed an online questionnaire battery assessing lifestyle and mental health. Of these, 538 participants completed the same battery 3 months later. We conducted negative binomial regressions to analyse the association of lifestyle factors at baseline with future (1) obsessive-compulsive symptoms, (2) compulsive problematic repetitive behaviours and (3) impulsive problematic repetitive behaviours, adjusting for baseline obsessive-compulsive symptoms and problematic repetitive behaviours. RESULTS: Lower vegetable (p = 0.020) and oily fish (p = 0.040) intake and lower moderate intensity physical activity (p = 0.008) predicted higher obsessive-compulsive symptoms at follow-up. Higher intake of high-fat foods (p < 0.001) predicted higher compulsive problematic repetitive behaviours at follow-up. No lifestyle factors significantly predicted impulsive problematic repetitive behaviours at follow-up. CONCLUSION: Our results speak to the potential importance of lifestyle quality screening, education and lifestyle interventions (e.g. an anti-inflammatory diet) for individuals experiencing compulsivity-related behaviours and/or symptoms. Further research into potential mechanisms of action will allow for more targeted approaches to lifestyle interventions for transdiagnostic compulsive behaviours.

Using the Theoretical Domains Framework to Inform the Implementation of Therapeutic Virtual Reality into Mental Healthcare.

Evidence supporting the efficacy of therapeutic virtual reality (VR) for mental health conditions is rapidly growing. However, little is known about how best to implement VR, or the challenges perceived by treatment providers. This study aimed to (1) synthesis perspectives of staff working in private mental healthcare and (2) use the Theoretical Domains Framework (TDF) and Behaviour Change Wheel (BCW) to identify mechanisms of change targets and intervention functions to facilitate its clinical implementation. Semi-structured interviews were conducted with clinicians (n = 14) and service managers (n = 5) working in a major private mental health hospital in Victoria, Australia. Transcripts were coded using framework analysis to identify relevant TDF domains. Specific belief statements were generated and coded as a barrier and/or facilitator and thematically organised within domains. Domains were ranked for importance based on frequency, elaboration, and evidence of conflicting beliefs. Using the BCW, domains were mapped to their respective COM-B components and indicated intervention functions. A total of 11 TDF domains were identified as relevant to early-stage implementation of therapeutic VR. Three domains were judged as highly important (beliefs about consequences; environmental context and resources; knowledge), while seven domains were judged as moderately important (social/professional role and identity; emotions; skills; memory, attention, and decision processes; intentions; beliefs about capabilities; social influences). Based on current data, we propose a theory-informed roadmap to promote VR uptake in mental healthcare services. A priority for intervention development should be addressing knowledge gaps and attitudinal barriers (e.g., safety concerns) with education and training.

Corrigendum: Implementation of Therapeutic Virtual Reality Into Psychiatric Care: Clinicians' and Service Managers' Perspectives.

[This corrects the article DOI: 10.3389/fpsyt.2021.791123.].

Are Australian Mental Health Services Ready for Therapeutic Virtual Reality? An Investigation of Knowledge, Attitudes, Implementation Barriers and Enablers.

Therapeutic virtual reality (VR) has the potential to address the challenges of equitable delivery of evidence-based psychological treatment. However, little is known about therapeutic VR regarding the perspectives and needs of real-world service providers. This exploratory study aimed to assess the acceptability, appropriateness, and feasibility of therapeutic VR among clinicians, managers, and service staff working in mental healthcare and explore potential implementation barriers and enablers. Eighty-one staff from a network of private psychiatric hospitals in Victoria, Australia (aged M + SD: 41.88 + 12.01 years, 71.6% female; 64% clinical staff) completed an online survey, which included the Acceptability of Intervention Measure (AIM), Appropriateness of Intervention Measure (IAM), and Feasibility of Intervention Measure (FIM). While 91% of participants had heard about VR technology, only 40% of participants had heard of therapeutic VR being used in mental healthcare, and none had used therapeutic VR in a clinical setting. Most participants perceived VR to be acceptable (84%), appropriate (69%), and feasible (59%) to implement within their role or service and envisioned a range of possible applications. However, participants expressed concerns regarding safety, efficacy, and logistical challenges across clinical settings. Findings suggest a strong interest for therapeutic VR among Australian mental health providers working in the private system. However, dissemination efforts should focus on addressing identified barriers to ensure mental health providers are adequately informed and empowered to make implementation decisions.

The role of psychological distress in the relationship between lifestyle and compulsivity: An analysis of independent, bi-national samples.

BACKGROUND: Poor mental health is a state of psychological distress that is influenced by lifestyle factors such as sleep, diet, and physical activity. Compulsivity is a transdiagnostic phenotype cutting across a range of mental illnesses including obsessive-compulsive disorder, substance-related and addictive disorders, and is also influenced by lifestyle. Yet, how lifestyle relates to compulsivity is presently unknown, but important to understand to gain insights into individual differences in mental health. We assessed (a) the relationships between compulsivity and diet quality, sleep quality, and physical activity, and (b) whether psychological distress statistically contributes to these relationships. METHODS: We collected harmonized data on compulsivity, psychological distress, and lifestyle from two independent samples (Australian n = 880 and US n = 829). We used mediation analyses to investigate bidirectional relationships between compulsivity and lifestyle factors, and the role of psychological distress. RESULTS: Higher compulsivity was significantly related to poorer diet and sleep. Psychological distress statistically mediated the relationship between poorer sleep quality and higher compulsivity, and partially statistically mediated the relationship between poorer diet and higher compulsivity. CONCLUSIONS: Lifestyle interventions in compulsivity may target psychological distress in the first instance, followed by sleep and diet quality. As psychological distress links aspects of lifestyle and compulsivity, focusing on mitigating and managing distress may offer a useful therapeutic approach to improve physical and mental health. Future research may focus on the specific sleep and diet patterns which may alter compulsivity over time to inform lifestyle targets for prevention and treatment of functionally impairing compulsive behaviors.

"Nothing to Lose, Absolutely Everything to Gain": Patient and Caregiver Expectations and Subjective Outcomes of Deep Brain Stimulation for Treatment-Resistant Depression.

Background: How "success" is defined in clinical trials of deep brain stimulation (DBS) for refractory psychiatric conditions has come into question. Standard quantitative psychopathology measures are unable to capture all changes experienced by patients and may not reflect subjective beliefs about the benefit derived. The decision to undergo DBS for treatment-resistant depression (TRD) is often made in the context of high desperation and hopelessness that can challenge the informed consent process. Partners and family can observe important changes in DBS patients and play a key role in the recovery process. Their perspectives, however, have not been investigated in research to-date. The aim of this study was to qualitatively examine patient and caregivers' understanding of DBS for TRD, their expectations of life with DBS, and how these compare with actual experiences and outcomes. Methods: A prospective qualitative design was adopted. Semi-structured interviews were conducted with participants (six patients, five caregivers) before DBS-implantation and 9-months after stimulation initiation. All patients were enrolled in a clinical trial of DBS of the bed nucleus of the stria terminalis. Interviews were thematically analyzed with data saturation achieved at both timepoints. Results: Two primary themes identified were: (1) anticipated vs. actual outcomes, and (2) trial decision-making and knowledge. The decision to undergo DBS was driven by the intolerability of life with severe depression coupled with the exhaustion of all available treatment options. Participants had greater awareness of surgical risks compared with stimulation-related risks. With DBS, patients described cognitive, emotional, behavioral and physical experiences associated with the stimulation, some of which were unexpected. Participants felt life with DBS was like "a roller coaster ride"-with positive, yet unsustained, mood states experienced. Many were surprised by the lengthy process of establishing optimum stimulation settings and felt the intervention was still a "work in progress." Conclusion: These findings support existing recommendations for iterative informed consent procedures in clinical trials involving long-term implantation of neurotechnology. These rich and descriptive findings hold value for researchers, clinicians, and individuals and families considering DBS. Narrative accounts capture patient and family needs and should routinely be collected to guide patient-centered approaches to DBS interventions.

The Effects of Combined Physical and Cognitive Training on Inhibitory Control: A Systematic Review and Meta-Analysis.

While strong inhibitory control is critical for health and wellbeing, there are no broadly applicable effective behavioural interventions that enhance it. This meta-analysis examined the neurocognitive rationale for combined physical and cognitive training and synthesised the rapidly growing body of evidence examining combined paradigms to enhance inhibitory control. Across the research to date, there was a small positive effect (n studies = 16, n participants = 832) of combined training on improving inhibitory control. Sub-group analyses showed small-moderate positive effects when the physical component of the combined training was moderately intense, as opposed to low or vigorous intensities; moderate positive effects were found in older adults, as compared to adolescents and adults; and healthy individuals and those with vascular cognitive impairment, as compared to ADHD, ASD, mild cognitive impairment and cancer survivors. This is the first meta-analysis to provide evidence that combined physical, specifically when moderately intense, and cognitive training has the capacity to improve inhibitory control, particularly when delivered to healthy individuals and those experiencing age-related decline.

Implementation of Therapeutic Virtual Reality Into Psychiatric Care: Clinicians' and Service Managers' Perspectives.

Objectives: Virtual reality (VR) has emerged as a highly promising tool for assessing and treating a range of mental illnesses. However, little is known about the perspectives of key stakeholders in mental healthcare, whose support will be critical for its successful implementation into routine clinical practise. This study aimed to explore the perspectives of staff working in the private mental health sector around the use of therapeutic VR, including potential implementation barriers and facilitators. Methods: Semi-structured qualitative interviews were conducted with cross-disciplinary clinicians (n = 14) and service managers (n = 5), aged 28-70 years working in a major private mental health hospital in Victoria, Australia. Transcripts were analysed using general inductive coding to allow themes to naturally emerge. Results: Three major themes were identified: clinical factors (four subthemes), organisational factors (five subthemes), and professional factors (three subthemes). The themes encompassed enabling factors and potential barriers that need to be addressed for successful implementation of VR. Clinical factors highlighted the influence of knowledge or perceptions about appropriate clinical applications, therapeutic efficacy, safety and ethical concerns, and patient engagement. Organisational factors emphasised the importance of service contexts, including having a strong business case, stakeholder planning, recruitment of local opinion leaders to champion change, and an understanding of resourcing challenges. Professional factors highlighted the need for education and training for staff, and the influence of staff attitudes towards technology and perceived usability of VR. Conclusions: In addition to enabling factors, potential implementation barriers of therapeutic VR were identified, including resourcing constraints, safety and ethical concerns, negative staff attitudes towards technology and VR system limitations. Future dissemination should focus on addressing knowledge and skills gaps and attitudinal barriers through development of clinical guidelines, training programs, and implementation resources (e.g., adoption decision tools, consultation opportunities).

"He's Back so I'm Not Alone": The Impact of Deep Brain Stimulation on Personality, Self, and Relationships in Parkinson's Disease.

Deep brain stimulation (DBS) for Parkinson's disease successfully alleviates motor symptoms, but unanticipated changes in personality, self, and relationships can occur. Little is known about how these nonmotor outcomes affect patients and families. We prospectively examined the experience and meaning of DBS-related changes in personality and self for patients and caregivers. In-depth, semi-structured interviews were conducted with 22 participants (11 patient-caregiver dyads) before and 9 months after DBS and analyzed using thematic analysis. We identified three themes present prior to DBS that reflected a time of anticipation, while three themes present after DBS reflected a process of adjustment. Participants noted both positive and negative personality changes, with some, but not all, attributing them to the stimulation. The risk of stimulation-related personality change should be weighed against the procedure's motor benefits and considered in the context of disease- and medication-related personality changes. Clinical implications including perioperative education and follow-up management are discussed.

Reward-related attentional capture and cognitive inflexibility interact to determine greater severity of compulsivity-related problems.

BACKGROUND AND OBJECTIVES: Neurocognitive processes are key drivers of addictive and compulsive disorders. The current study examined whether reward-related attentional capture and cognitive inflexibility are associated with impulsive and/or compulsive personality traits, and whether these cognitive characteristics interact to predict greater compulsivity-related problems across obsessive-compulsive and drinking behaviors. METHODS: One-hundred and seventy-three participants (mean age = 34.5 years, S.D = 8.4, 42% female) completed an online visual search task to measure reward-related attentional capture and its persistence following reversal of stimulus-reward contingencies. Participants also completed questionnaires to assess trait impulsivity, compulsivity, alcohol use, and obsessive-compulsive behaviors. RESULTS: Greater reward-related attentional capture was associated with trait compulsivity, over and above all impulsivity dimensions, while greater cognitive inflexibility was associated with higher negative urgency (distress-elicited impulsivity). Reward-related attentional capture and cognitive inflexibility interacted to predict greater compulsivity-related problems among participants who reported obsessive-compulsive behaviors in the past month (n = 57) as well as current drinkers (n = 88). Follow-up analyses showed that, for OCD behaviors, this interaction was driven by an association between higher reward-related attentional capture and more problematic behaviors among cognitively inflexible participants only. For drinking, the same pattern was seen, albeit at trend level. LIMITATIONS: This study includes a non-clinical, online sample and is cross-sectional, thus its findings need to be interpreted with these limitations in mind. CONCLUSIONS: Reward-related attentional capture and cognitive flexibility are related to trait compulsivity and impulsivity (negative urgency) respectively, and interact to determine more problematic behaviors.

Compulsivity is measurable across distinct psychiatric symptom domains and is associated with familial risk and reward-related attentional capture.

BACKGROUND: Compulsivity can be seen across various mental health conditions and refers to a tendency toward repetitive habitual acts that are persistent and functionally impairing. Compulsivity involves dysfunctional reward-related circuitry and is thought to be significantly heritable. Despite this, its measurement from a transdiagnostic perspective has received only scant research attention. Here we examine both the psychometric properties of a recently developed compulsivity scale, as well as its relationship with compulsive symptoms, familial risk, and reward-related attentional capture. METHODS: Two-hundred and sixty individuals participated in the study (mean age = 36.0 [SD = 10.8] years; 60.0% male) and completed the Cambridge-Chicago Compulsivity Trait Scale (CHI-T), along with measures of psychiatric symptoms and family history thereof. Participants also completed a task designed to measure reward-related attentional capture (n = 177). RESULTS: CHI-T total scores had a normal distribution and acceptable Cronbach's alpha (0.84). CHI-T total scores correlated significantly and positively (all p < 0.05, Bonferroni corrected) with Problematic Usage of the Internet, disordered gambling, obsessive-compulsive symptoms, alcohol misuse, and disordered eating. The scale was correlated significantly with history of addiction and obsessive-compulsive related disorders in first-degree relatives of participants and greater reward-related attentional capture. CONCLUSIONS: These findings suggest that the CHI-T is suitable for use in online studies and constitutes a transdiagnostic marker for a range of compulsive symptoms, their familial loading, and related cognitive markers. Future work should more extensively investigate the scale in normative and clinical cohorts, and the role of value-modulated attentional capture across compulsive disorders.

The influence of endogenous estrogen on high-frequency prefrontal transcranial magnetic stimulation.

BACKGROUND: The use of repetitive transcranial magnetic stimulation (rTMS) as both therapeutic and experimental tools has grown enormously over the past decade. However, variability in response to rTMS is one challenge that remains to be solved. Estrogen can impact neural plasticity and may also affect plastic changes following rTMS. The present study investigated whether estrogen levels influence the neurophysiological effects of high-frequency (HF) rTMS in the left dorsolateral prefrontal cortex (DLPFC). HYPOTHESIS: It was hypothesised that individuals with higher endogenous estrogen would demonstrate greater rTMS-induced changes in cortical reactivity. METHODS: 29 healthy adults (15M/14F) received HF-rTMS over left DLPFC. Females attended two sessions, one during a high-estrogen (HE) phase of the menstrual cycle, another during a low-estrogen (LE) phase. Males attended one session. Estrogen level was verified via blood assay. TMS-EEG was used to probe changes in cortical plasticity and comparisons were made using cluster-based permutation statistics and Bayesian analysis. RESULTS: In females, a significant increase in TMS-evoked P60 amplitude, and decrease in N45, N100 and P180 amplitudes was observed during HE. A less pervasive pattern of change was observed during LE. No significant changes in TEPs were seen in males. Between-condition comparisons revealed higher likelihood of the change in N100 and/or P180 being larger in females during HE compared to both females during LE and males. CONCLUSIONS: These preliminary findings indicate that a greater neuroplastic response to prefrontal HF-rTMS is seen in women when estrogen is at its highest compared to men, suggesting that endogenous estrogen levels contribute to variability in response to HF-rTMS.

Overlapping dimensional phenotypes of impulsivity and compulsivity explain co-occurrence of addictive and related behaviors.

OBJECTIVE: Impulsivity and compulsivity have been implicated as important transdiagnostic dimensional phenotypes with potential relevance to addiction. We aimed to develop a model that conceptualizes these constructs as overlapping dimensional phenotypes and test whether different components of this model explain the co-occurrence of addictive and related behaviors. METHODS: A large sample of adults (N = 487) was recruited through Amazon's Mechanical Turk and completed self-report questionnaires measuring impulsivity, intolerance of uncertainty, obsessive beliefs, and the severity of 6 addictive and related behaviors. Hierarchical clustering was used to organize addictive behaviors into homogenous groups reflecting their co-occurrence. Structural equation modeling was used to evaluate fit of the hypothesized bifactor model of impulsivity and compulsivity and determine the proportion of variance explained in the co-occurrence of addictive and related behaviors by each component of the model. RESULTS: Addictive and related behaviors clustered into 2 distinct groups: Impulse-Control Problems, consisting of harmful alcohol use, pathological gambling, and compulsive buying, and Obsessive-Compulsive-Related Problems, consisting of obsessive-compulsive symptoms, binge eating, and internet addiction. The hypothesized bifactor model of impulsivity and compulsivity provided the best empirical fit, with 3 uncorrelated factors corresponding to a general Disinhibition dimension, and specific Impulsivity and Compulsivity dimensions. These dimensional phenotypes uniquely and additively explained 39.9% and 68.7% of the total variance in Impulse-Control Problems and Obsessive-Compulsive-Related Problems. CONCLUSION: A model of impulsivity and compulsivity that represents these constructs as overlapping dimensional phenotypes has important implications for understanding addictive and related behaviors in terms of shared etiology, comorbidity, and potential transdiagnostic treatments.

The influence of endogenous estrogen on transcranial direct current stimulation: A preliminary study.

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulatory technique. Responses to tDCS differ substantially between individuals. Sex hormones that modulate cortical excitability, such as estrogen, may contribute to this inter-individual variability. The influence of estrogen on tDCS after-effects has not yet been researched. This study aimed to investigate whether endogenous estrogen levels influence cortical response to tDCS. Data from 15 male and 14 female healthy adults were analyzed. Males completed one experimental session. Females completed two, one during the early follicular phase of the menstrual cycle when estrogen was low, one during the mid-luteal phase when estrogen was high. Each session comprised 15-min of anodal tDCS delivered to the left dorsolateral prefrontal cortex (DLPFC). Response to stimulation was assessed using electroencephalography with DLPFC transcranial magnetic stimulation (TMS) administered before, immediately after, and 20-min after tDCS. Changes in amplitudes of N120 and P200 components of TMS-evoked potentials over time were compared between males, women with low estrogen and women with high estrogen. Blood assays verified estrogen levels. Women with high estrogen demonstrated a significant increase in P200 amplitude at both time points and change over time was greater for the high estrogen group compared with males. No significant differences were observed between males and women with low estrogen, or between women with low and high estrogen. These preliminary results indicate that greater neuroplastic response to DLPFC tDCS is seen in highest compared with lowest estrogen states, suggesting that endogenous estrogen levels contribute to inter-individual variability of tDCS outcomes.

Unpacking the role of self-reported compulsivity and impulsivity in obsessive-compulsive disorder.

OBJECTIVE: We aimed to determine whether individuals with obsessive-compulsive disorder (OCD) and demographically matched healthy individuals can be clustered into distinct clinical subtypes based on dimensional measures of their self-reported compulsivity (OBQ-44 and IUS-12) and impulsivity (UPPS-P). METHODS: Participants (n=217) were 103 patients with a clinical diagnosis of OCD; 79 individuals from the community who were "OCD-likely" according to self-report (Obsessive-Compulsive Inventory-Revised scores equal or greater than 21); and 35 healthy controls. All data were collected between 2013 and 2015 using self-report measures that assessed different aspects of compulsivity and impulsivity. Principal component analysis revealed two components broadly representing an individual's level of compulsivity and impulsivity. Unsupervised clustering grouped participants into four subgroups, each representing one part of an orthogonal compulsive-impulsive phenotype. RESULTS: Clustering converged to yield four subgroups: one group low on both compulsivity and impulsivity, comprised mostly of healthy controls and demonstrating the lowest OCD symptom severity; two groups showing roughly equal clinical severity, but with opposing drivers (i.e., high compulsivity and low impulsivity, and vice versa); and a final group high on both compulsivity and impulsivity and recording the highest clinical severity. Notably, the largest cluster of individuals with OCD was characterized by high impulsivity and low compulsivity. Our results suggest that both impulsivity and compulsivity mediate obsessive-compulsive symptomatology. CONCLUSIONS: Individuals with OCD can be clustered into distinct subtypes based on measures of compulsivity and impulsivity, with the latter being found to be one of the more defining characteristics of the disorder. These dimensions may serve as viable and novel treatment targets.