Placebo effects in randomized trials of pharmacological and neurostimulation interventions for mental disorders: An umbrella review.

There is a growing literature exploring the placebo response within specific mental disorders, but no overarching quantitative synthesis of this research has analyzed evidence across mental disorders. We carried out an umbrella review of meta-analyses of randomized controlled trials (RCTs) of biological treatments (pharmacotherapy or neurostimulation) for mental disorders. We explored whether placebo effect size differs across distinct disorders, and the correlates of increased placebo effects. Based on a pre-registered protocol, we searched Medline, PsycInfo, EMBASE, and Web of Knowledge up to 23.10.2022 for systematic reviews and/or meta-analyses reporting placebo effect sizes in psychopharmacological or neurostimulation RCTs. Twenty meta-analyses, summarising 1,691 RCTs involving 261,730 patients, were included. Placebo effect size varied, and was large in alcohol use disorder (g = 0.90, 95% CI [0.70, 1.09]), depression (g = 1.10, 95% CI [1.06, 1.15]), restless legs syndrome (g = 1.41, 95% CI [1.25, 1.56]), and generalized anxiety disorder (d = 1.85, 95% CI [1.61, 2.09]). Placebo effect size was small-to-medium in obsessive-compulsive disorder (d = 0.32, 95% CI [0.22, 0.41]), primary insomnia (g = 0.35, 95% CI [0.28, 0.42]), and schizophrenia spectrum disorders (standardized mean change = 0.33, 95% CI [0.22, 0.44]). Correlates of larger placebo response in multiple mental disorders included later publication year (opposite finding for ADHD), younger age, more trial sites, larger sample size, increased baseline severity, and larger active treatment effect size. Most (18 of 20) meta-analyses were judged 'low' quality as per AMSTAR-2. Placebo effect sizes varied substantially across mental disorders. Future research should explore the sources of this variation. We identified important gaps in the literature, with no eligible systematic reviews/meta-analyses of placebo response in stress-related disorders, eating disorders, behavioural addictions, or bipolar mania.

Duration of untreated illness in gambling disorder.

OBJECTIVE: Gambling disorder is common, affects 0.5-2% of the population, and is under-treated. Duration of untreated illness (DUI) has emerged as a clinically important concept in the context of other mental disorders, but DUI in gambling disorder, has received little research scrutiny. METHODS: Data were aggregated from previous clinical trials in gambling disorder with people who had never previously received any treatment. DUI was quantified, and clinical characteristics were compared as a function of DUI status. RESULTS: A total of 298 individuals were included, and the mean DUI (standard deviation) was 8.9 (8.4) years, and the median DUI was 6 years. Longer DUI was significantly associated with male gender, older age, earlier age when the person first started to gamble, and family history of alcohol use disorder. Longer DUI was not significantly associated with racial-ethnic status, gambling symptom severity, current depressive or anxiety severity, comorbidities, or disability/functioning. The two groups did not differ in their propensity to drop out of the clinical trials, nor in overall symptom improvement associated with participation in those trials. CONCLUSIONS: These data suggest that gambling disorder has a relatively long DUI and highlight the need to raise awareness and foster early intervention for affected and at-risk individuals. Because earlier age at first gambling in any form was strongly linked to longer DUI, this highlights the need for more rigorous legislation and education to reduce exposure of younger people to gambling.

Lifetime alcohol use disorder and gambling disorder: clinical profile and treatment response.

OBJECTIVES: Gambling disorder affects 0.5-2.4% of the population and shows strong associations with lifetime alcohol use disorder. Very little is known regarding whether lifetime alcohol use disorder can impact the clinical presentation or outcome trajectory of gambling disorder. METHODS: Data were pooled from previous clinical trials conducted on people with gambling disorder, none of whom had current alcohol use disorder. Demographic and clinical variables were compared between those who did versus did not have lifetime alcohol use disorder. RESULTS: Of the 621 participants in the clinical trials, 103 (16.6%) had a lifetime history of alcohol use disorder. History of alcohol use disorder was significantly associated with male gender (relative risk [RR] = 1.42), greater body weight (Cohen's D = 0.27), family history of alcohol use disorder in first-degree relative(s) (RR = 1.46), occurrence of previous hospitalization due to psychiatric illness (RR = 2.68), and higher gambling-related legal problems (RR = 1.50). History of alcohol use disorder was not significantly associated with other variables that were examined, such as severity of gambling disorder or extent of functional disability. Lifetime alcohol use disorder was not significantly associated with the extent of clinical improvement in gambling disorder symptoms during the subsequent clinical trials. CONCLUSIONS: These data highlight that lifetime alcohol use disorder is an important clinical variable to be considered when assessing gambling disorder because it is associated with several untoward features (especially gambling-related legal problems and prior psychiatric hospitalization). The study design enabled these associations to be disambiguated from current or recent alcohol use disorder.

Emotion regulation across psychiatric disorders.

OBJECTIVE: Difficulties with emotion regulation have been associated with multiple psychiatric conditions. In this study, we aimed to investigate emotional regulation difficulties in young adults who gamble at least occasionally (ie, an enriched sample), and diagnosed with a range of psychiatric disorders using the validated Difficulties in Emotion Regulation Scale (DERS). METHODS: A total of 543 non-treatment-seeking individuals who had engaged in gambling activities on at least 5 occasions within the previous year, aged 18-29 were recruited from general community settings. Diagnostic assessments included the Mini International Neuropsychiatric Inventory, Minnesota Impulsive Disorders Interview, attention-deficit/hyperactivity disorder World Health Organization Screening Tool Part A, and the Structured Clinical Interview for Gambling Disorder. Emotional dysregulation was evaluated using DERS. The profile of emotional dysregulation across disorders was characterized using Z-scores (those with the index disorder vs. those without the index disorder). RESULTS: Individuals with probable ADHD displayed the highest level of difficulties in emotional regulation, followed by intermittent explosive disorder, social phobia, and generalized anxiety disorder. In contrast, participants diagnosed with obsessive-compulsive disorder showed relatively lower levels of difficulties with emotional regulation. CONCLUSIONS: This study highlights the importance of recognizing emotional dysregulation as a trans-diagnostic phenomenon across psychiatric disorders. The results also reveal differing levels of emotional dysregulation across diagnoses, with potential implications for tailored treatment approaches. Despite limitations such as small sample sizes for certain disorders and limited age range, this study contributes to a broader understanding of emotional regulation's role in psychiatric conditions.

Cognition in trichotillomania: a meta-analysis.

OBJECTIVE: Trichotillomania (TTM) is a mental health disorder characterized by repetitive urges to pull out one's hair. Cognitive deficits have been reported in people with TTM compared to controls; however, the current literature is sparse and inconclusive about affected domains. We aimed to synthesize research on cognitive functioning in TTM and investigate which cognitive domains are impaired. METHODS: After preregistration on the International Prospective Register of Systematic Reviews (PROSPERO), we conducted a comprehensive literature search for papers examining cognition in people with TTM versus controls using validated tests. A total of 793 papers were screened using preestablished inclusion/exclusion criteria, yielding 15 eligible studies. Random-effects meta-analysis was conducted for 12 cognitive domains. RESULTS: Meta-analysis demonstrated significant deficits in motor inhibition and extradimensional (ED) shifting in people with TTM versus controls as measured by the stop-signal task (SST) (Hedge's g = 0.45, [CI: 0.14, 0.75], p = .004) and ED set-shift task (g = 0.38, [CI: 0.13, 0.62], p = .003), respectively. There were no significant between-group differences in the other cognitive domains tested: verbal learning, intradimensional (ID) shifting, road map spatial ability, pattern recognition, nonverbal memory, executive planning, spatial span length, Stroop inhibition, Wisconsin card sorting, and visuospatial functioning. Findings were not significantly moderated by study quality scores. CONCLUSIONS: Motor inhibition and ED set-shifting appear impaired in TTM. However, a cautious interpretation of results is necessary as samples were relatively small and frequently included comorbidities. Treatment interventions seeking to improve inhibitory control and cognitive flexibility merit exploration for TTM.

A systematic review of the cognitive effects of the COMT inhibitor, tolcapone, in adult humans.

OBJECTIVE: The catechol-o-methyltransferase (COMT) inhibitor tolcapone constitutes a potentially useful probe of frontal cortical dopaminergic function. The aim of this systematic review was to examine what is known of effects of tolcapone on human cognition in randomized controlled studies. METHODS: The study protocol was preregistered on the Open Science Framework. A systematic review was conducted using PubMed to identify relevant randomized controlled trials examining the effects of tolcapone on human cognition. Identified articles were then screened against inclusion and exclusion criteria. RESULTS: Of the 22 full-text papers identified, 13 randomized control trials were found to fit the pre-specified criteria. The most consistent finding was that tolcapone modulated working memory; however, the direction of effect appeared to be contingent on the COMT polymorphism (more consistent evidence of improvement in Val-Val participants). There were insufficient nature and number of studies for meta-analysis. CONCLUSION: The cognitive improvements identified upon tolcapone administration, in some studies, are likely to be due to the level of dopamine in the prefrontal cortex being shifted closer to its optimum, per an inverted U model of prefrontal function. However, the results should be interpreted cautiously due to the small numbers of studies. Given the centrality of cortical dopamine to understanding human cognition, studies using tolcapone in larger samples and across a broader set of cognitive domains would be valuable. It would also be useful to explore the effects of different dosing regimens (different doses; and single versus repeated administration).

Monoamine Oxidase Inhibitors for Trichotillomania: A Case Series.

PURPOSE/BACKGROUND: Despite several decades of research, there are no US Food and Drug Administration-approved medications for trichotillomania or medications generally approved in other geographical jurisdictions. Monoamine oxidase inhibitors show efficacy in the treatment of depression and some possible promise for obsessive compulsive disorder. METHODS/PROCEDURES: We present new data from a case series collected in a specialty clinical practice over a 4-year period. FINDINGS/RESULTS: In 5 treatment-resistant patients whose trichotillomania had not improved with at least 1 course of cognitive behavior therapy and trials of n -acetyl cysteine, an antipsychotic, and a serotonin selective reuptake inhibitor, 2 had marked clinical improvement (>40% improvement) on phenelzine, 1 improved on tranylcypromine, and 2 showed no improvement (<10%) on phenelzine. In 2 of the 3 patients who experienced improvement, there was co-occurring depression. IMPLICATIONS/CONCLUSIONS: Monoamine oxidase inhibitors in trichotillomania may deserve large-scale randomized controlled trials, particularly in specialist settings where first-line interventions have proven inadequate to manage severe symptoms.

Structural gray matter differences in Problematic Usage of the Internet: a systematic review and meta-analysis.

Problematic Usage of the Internet (PUI) has been linked to diverse structural gray matter changes in individual data studies. However, no quantitative synthesis across studies has been conducted. We aimed to identify gray matter regions showing significant spatial convergence across neuroimaging studies in PUI. We searched PubMed and PsycINFO up to 10/03/2021 and included original, cross-sectional comparative studies that examined structural gray matter imaging in PUI versus control groups; reported a whole-brain analysis; and provided peak coordinates for gray matter differences. From a total of 624 potentially relevant studies, 15 (including 355 individuals with PUI and 363 controls) were included in a meta-analysis of voxel-based morphometry studies. Anatomical likelihood estimation (ALE) meta-analysis was performed using extracted coordinates and identified significant spatial convergence in the medial/superior frontal gyri, the left anterior cingulate cortex/cingulate gyrus, and the left middle frontal/precentral gyri. Datasets contributing to these findings all indicated reduced gray matter in cases compared to controls. In conclusion, voxel-based morphometric studies indicate replicable gray matter reductions in the dorsolateral prefrontal cortex and anterior cingulate cortex in PUI, regions implicated in reward processing and top-down inhibitory control. Further studies are required to understand the nature of gray matter differences across PUI behaviors, as well as the contribution of particular mental health disorders, and the influence of variation in study and sample characteristics.

Does gambling differ in people with a minority sexual orientation?

BACKGROUND: Gambling is common and there is growing concern about its public health implications. Little is known about how gambling differs in people with minority sexual identities. We sought to understand whether lesbian, gay, and bisexual (LGB) individuals differ from non-LGB individuals in terms of gambling and associated characteristics. METHODS: A total of 534 participants age 18 to 29 who gambled at least 5 times in the preceding year undertook clinical and neurocognitive evaluations. Those who identified as LGB were compared to heterosexuals on clinical and cognitive measures. RESULTS: Overall, 51 participants (9.6%) identified as LGB. These individuals showed significantly higher levels of problem gambling, suicide risk, substance use disorders, traits of obsessive-compulsive personality disorder (OCPD), higher errors on a set-shifting task, and higher rates of family history of addiction. CONCLUSIONS: These results indicate that individuals with minority sexual orientations may be at higher risk of experiencing problem gambling and associated factors, such as increased suicidality, OCPD traits, and some degree of cognitive differences. Future studies should establish whether these associations also exist in clinical samples of people with full gambling disorder. Large-scale longitudinal research in neglected minority groups is needed to further explore these associations.

Clinical characteristics of trichotillomania.

BACKGROUND: Trichotillomania is a common psychiatric disorder classified as an obsessive-compulsive and related condition in DSM-5. Despite being first described in the 1800s, little is known about its phenomenology and clinical presentation. Most information about trichotillomania is based on small samples. METHODS: Clinical and demographic data were collected from 858 individuals with trichotillomania who participated in research studies that used in-person assessments with validated instruments. RESULTS: A total of 858 adolescents and adults (mean age 29.3; range 11 to 65; 89.9% female) were recruited. The peak age of symptom onset was 11 to 15, and most affected individuals (93.5%) had symptom onset before age 20. Individuals reported pulling from several body sites, and the most frequent triggers were stress and the feel of their hair. Comorbidities included major depressive disorder, generalized anxiety disorder, and skin picking disorder. Most individuals with trichotillomania (61.7%) previously had received treatment. Among those who had received treatment, more individuals had received medication (43.4%) than psychotherapy (33.0%). CONCLUSIONS: This study sheds new light on the clinical presentation and phenomenology of trichotillomania. Results highlight the need for further research into its clinical presentation, longitudinal course, and optimal treatment approaches.

Temperament in trichotillomania and skin picking disorder.

BACKGROUND: Trichotillomania (TTM) and skin picking disorder (SPD) result in significant psychosocial burden. Despite this burden, however, risk factors related to the development of these disorders remain unclear. The present study assessed temperament in a well-characterized sample of adults with TTM or SPD. METHODS: A total of 202 adults age 18 to 65 were enrolled; 44 had TTM, 30 had SPD, and 128 served as controls. Participants completed the self-report Tridimensional Personality Questionnaire (TPQ) to examine the severity of TTM and SPD symptoms, quality of life, and temperament. Group differences were characterized and correlations with other measures were examined. RESULTS: Compared to controls, those with TTM or SPD scored significantly higher on harm avoidance and its subscales, with TTM associated with higher scores than SPD. Those with TTM or SPD scored significantly higher on only 1 measure of novelty seeking (extravagance). Higher TPQ harm avoidance correlated with worse hair pulling severity and worse quality of life. CONCLUSIONS: The temperament traits of participants with TTM or SPD differed in significant ways from controls; those with TTM or SPD generally demonstrated similar trait profiles. A dimensional approach to the personalities of those with TTM or SPD may offer insight and provide clues to treatment strategies.

Trichotillomania in sexual minority individuals.

BACKGROUND: Trichotillomania is a common psychiatric disorder, but little is known about whether or how it differs in people with minority sexual identities. We sought to understand whether lesbian, gay, bisexual, and other individuals differ from heterosexual individuals in terms of hair pulling and associated characteristics. METHODS: A total of 207 participants age 18 to 64 with trichotillomania undertook clinical evaluations. Those who identified as sexual minorities were compared to those who identified as heterosexuals on clinical measures, comorbidities, impulsivity, and stress responses. RESULTS: Overall, 33 participants (15.9%) identified as sexual minorities. These individuals showed significantly higher levels of attentional impulsivity and higher rates of co-occurring obsessive-compulsive disorder compared to heterosexual participants. The groups did not differ in terms of trichotillomania severity or dysfunction due to trichotillomania or in terms of stress response CONCLUSIONS: The rate of sexual minorities in this study (15.9%) is higher than recent US Census Bureau data for sexual minorities in the US population (11.7%). People with trichotillomania from sexual minority groups may present with unique clinical symptoms. Treatments may need to be tailored for this population.

Attentional problems occur across multiple psychiatric disorders and are not specific for ADHD.

OBJECTIVE: Attentional problems are common and have been associated with multiple psychiatric disorders. This study examined problems of sustained attention across a range of psychiatric disorders using a validated computerized trans-diagnostic attentional paradigm (a continuous performance task). We hypothesized that multiple psychiatric disorders, particularly attention deficit hyperactivity disorder (ADHD), would be associated with pronounced attentional problems. METHODS: Totally, 576 non-treatment seeking participants (aged 18-29 years) were enrolled from general community settings, provided demographic variables, and underwent clinical assessments to detect mental health disorders. Each participant underwent the rapid visual information processing task, a validated computerized test measuring sustained attention. The two measures of sustained attention were the sensitivity index and target detection (proportion of targets detected). The profile of attentional deficits was examined across different disorders using z-scores relative to controls. RESULTS: Participants with social phobia, obsessive-compulsive disorder (OCD), bulimia nervosa, and intermittent explosive disorder showed the greater impairment in target sensitivity, all with effect sizes of at least 0.8. Target detection was impaired across multiple disorders, with OCD and binge eating disorder exhibiting the most pronounced impairment. Post-traumatic stress disorder (PTSD) and compulsive sexual behavior were associated with particularly spared performance on both measures. DISCUSSION: These data indicate that impaired attention is non-specific for ADHD and in fact several other disorders are associated with markedly larger deficits. Instead of clinicians assuming sustained attention problems are due to ADHD, a variety of disorders should be screened for when people report attentional problems. Future work should examine the contribution of comorbidities and psychoactive substances (prescribed or illicit) to the profiles identified.

Impaired cognitive flexibility across psychiatric disorders.

OBJECTIVE: Problems with cognitive flexibility have been associated with multiple psychiatric disorders, but there has been little understanding of how cognitive flexibility compares across these disorders. This study examined problems of cognitive flexibility in young adults across a range of psychiatric disorders using a validated computerized trans-diagnostic flexibility paradigm. We hypothesized that obsessive-compulsive spectrum disorders (eg, obsessive-compulsive disorder, trichotillomania, and skin-picking disorder) would be associated with pronounced flexibility problems as they are most often associated with irrational or purposeless repetitive behaviors. METHODS: A total of 576 nontreatment seeking participants (aged 18-29 years) were enrolled from general community settings, provided demographic information, and underwent structured clinical assessments. Each participant undertook the intra-extra-dimensional task, a validated computerized test measuring set-shifting ability. The specific measures of interest were total errors on the task and performance on the extra-dimensional (ED) shift, which reflects the ability to inhibit and shift attention away from one stimulus dimension to another. RESULTS: Participants with depression and PTSD had elevated total errors on the task with moderate effect sizes; and those with the following had deficits of small effect size: generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), antisocial personality disorder, and binge-eating disorder. For ED errors, participants with PTSD, GAD, and binge-eating disorder exhibited deficits with medium effect sizes; those with the following had small effect size deficits: depression, social anxiety disorder, OCD, substance dependence, antisocial personality disorder, and gambling disorder. CONCLUSIONS: These data indicate cognitive flexibility deficits occur across a range of mental disorders. Future work should explore whether these deficits can be ameliorated with novel treatment interventions.

Binge-eating disorder in university students: high prevalence and strong link to impulsive and compulsive traits.

BACKGROUND: Binge eating disorder (BED) is the most common eating disorder, and is associated with significant comorbidity, with university students being particularly vulnerable. We aimed to assess associations of BED with a wide range of comorbidities and measures of impulsivity and compulsivity in university students, to gain better understanding of its prevalence, correlates and pathophysiology. METHODS: We carried out an internet-based survey, assessing presence of BED using a validated structured self-report diagnostic tool, demographics, substance use, impulsive behaviors, psychiatric history, and measures of impulsivity and compulsivity. Approximately 10 000 students were invited to take part. Group differences between students with current BED and students without BED were investigated. RESULTS: A total of 3415 students completed the survey, with 83 (2.4%) screening positive for BED. BED was associated with female gender, hazardous/harmful alcohol use, depression and anxiety symptoms, low self-esteem, post-traumatic stress disorder, attention-deficit/hyperactivity disorder, treatment for psychological/emotional problems (including prescribed medication) and trait impulsivity and compulsivity. However, the largest effect sizes were evident for associations with trait impulsivity and compulsivity. CONCLUSIONS: The associations of BED with trait impulsivity and compulsivity implicate these latent phenotypes in its pathophysiology. The identified links between BED and a wide range of mental disorders highlight the need to screen for disordered eating in student populations, including when students present with other mental health conditions.

Religiosity, impulsivity, and compulsivity in university students.

OBJECTIVES: Prior research suggests that religiosity may be associated with healthier levels of mental health in certain domains (eg, higher self-esteem and lower rates of substance use problems). However, very little is known about religiosity and impulsive plus compulsive tendencies. This study examined associations between religiosity and impulsive and compulsive behaviors and traits among university students. METHODS: Nine thousand, four hundred and forty-nine students received a 156-item anonymous online survey which assessed religiosity, alcohol and drug use, mental health issues, and impulsive and compulsive traits. Two groups of interest were defined: those with high religiosity, and those with low religiosity, based on z-scores. The two groups were compared on the measures of interest. RESULTS: Three thousand, five hundred and seventy-two university students (57.1% female) responded to the survey. Those with high levels of organizational religious activity, as well as those with high levels of intrinsic or subjective religiosity, differed from their fellow students in having better self-esteem, being less likely to have alcohol or drug problems, and generally being less impulsive in terms of attention and planning. Compulsivity did not differ between groups. Associations were of small effect size except for the link between religiosity and lower impulsivity, which was of medium effect size. CONCLUSION: This study shows a link between higher religiosity and lower impulsivity, as well as higher levels of mental health across several domains. Whether these associations are causal-and if so, the direction of such causality-requires rigorous longitudinal research.

Cognition in adults with borderline personality disorder.

OBJECTIVE: Borderline personality disorder (BPD) is a common and disabling mental health disorder and has detrimental effects on affected individuals across multiple domains. We aimed to investigate whether individuals with BPD differ from control subjects in terms of cognitive functions, and to see if there is a relationship between cognitive functions, impulsivity, and BPD symptom severity. METHODS: BPD individuals (n = 26; mean age = 26.7; 69.2% female) and controls (n = 58; mean age = 25.3; 51.7% female) were enrolled. Intra/Extra-Dimensional Set Shift (IED) and One Touch Stockings of Cambridge (OTS) tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to assess cognitive functions. Barratt Impulsivity Scale-version 11 (BIS-11) was administered to measure impulsivity and both the Zanarini Scale for Borderline Personality Disorder self-report and the clinician-administered versions were used to assess BPD symptom severity. RESULTS: BPD group showed significantly impaired cognitive performance on the IED task versus controls, but there was not a significant difference in the OTS task. BPD symptom severity was positively correlated with trait (BIS-11) impulsivity and no correlation was found between BPD symptom severity and cognitive functions. CONCLUSIONS: This study suggests people with BPD experience impaired cognitive flexibility and heightened impulsivity. Only impulsivity appeared to be directly related to symptom severity, perhaps indicating that cognitive inflexibility could be a vulnerability marker. Future research should focus on a longitudinal approach to extend clinical and theoretical knowledge in this area.

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.

Neurobiology of subtypes of trichotillomania and skin picking disorder.

BACKGROUND: Trichotillomania (TTM) and skin picking disorder (SPD) are common and often debilitating mental health conditions, grouped under the umbrella term of body-focused repetitive behaviors (BFRBs). Recent clinical subtyping found that there were three distinct subtypes of TTM and two of SPD. Whether these clinical subtypes map on to any unique neurobiological underpinnings, however, remains unknown. METHODS: Two hundred and fifty one adults [193 with a BFRB (85.5% [n = 165] female) and 58 healthy controls (77.6% [n = 45] female)] were recruited from the community for a multicenter between-group comparison using structural neuroimaging. Differences in whole brain structure were compared across the subtypes of BFRBs, controlling for age, sex, scanning site, and intracranial volume. RESULTS: When the subtypes of TTM were compared, low awareness hair pullers demonstrated increased cortical volume in the lateral occipital lobe relative to controls and sensory sensitive pullers. In addition, impulsive/perfectionist hair pullers showed relative decreased volume near the lingual gyrus of the inferior occipital-parietal lobe compared with controls. CONCLUSIONS: These data indicate that the anatomical substrates of particular forms of BFRBs are dissociable, which may have implications for understanding clinical presentations and treatment response.

Internet severity and activities addiction questionnaire (ISAAQ): Psychometrics of item response theory and clustering of online activities.

BACKGROUND: Problematic usage of the internet (PUI) is an umbrella term, referring to a variety of maladaptive online behaviors linked to functional impairment. There is ongoing need for the development of instruments capturing not only PUI severity, but also the online activity types. The Internet Severity and Activities Questionnaire (ISAAQ), previously developed to address this need, required further refinement and validation. METHODS: Cross-sectional data was gathered in two separate samples (South Africa n = 3275, USA-UK n = 943) using the Internet Severity and Activities Addiction Questionnaire (ISAAQ). Item Response Theory (IRT) was used to examine the properties of the scale (Part A of the ISAAQ) and differential item functioning against demographic parameters. The severity scale of the ISAAQ was optimized by eliminating the poorest performing items using an iterative approach and examining validity metrics. Cluster analyses was used to examine internet activities and commonalities across samples (Part B of the ISAAQ). RESULTS: Optimization of ISAAQ using IRT yielded a refined 10-item version (ISAAQ-10), with less differential item functioning and a robust unidimensional factor structure. The ISAAQ-10 severity score correlated strongly with established measures of internet addiction (Compulsive Internet Use Scale [Person's r = 0.86] and the Internet Addiction Test-10 [r = 0.75]). Combined with gaming activity score it correlated moderately strongly with the established Internet Gaming Disorder Test (r = 0.65). Exploratory cluster analyses in both samples identified two groups, one of "low-PUI" [98.1-98.5%], and one of "high-PUI" [1.5-1.9%]. Multiple facets of internet activity appeared elevated in the high-PUI cluster. DISCUSSION: The ISAAQ-10 supersedes the earlier longer version of the ISAAQ, and provides a useful, psychometrically robust measure of PUI severity (Part A), and captures the extent of engagement in a wide gamut of online specific internet activities (Part B). ISAAQ-10 constitutes a valuable objective measurement tool for future studies.