Genome-Wide Association Study of Obsessive-Compulsive Symptoms including 33,943 individuals from the general population.

While 1-2% of individuals meet the criteria for a clinical diagnosis of obsessive-compulsive disorder (OCD), many more (~13-38%) experience subclinical obsessive-compulsive symptoms (OCS) during their life. To characterize the genetic underpinnings of OCS and its genetic relationship to OCD, we conducted the largest genome-wide association study (GWAS) meta-analysis of parent- or self-reported OCS to date (N = 33,943 with complete phenotypic and genome-wide data), combining the results from seven large-scale population-based cohorts from Sweden, the Netherlands, England, and Canada (including six twin cohorts and one cohort of unrelated individuals). We found no genome-wide significant associations at the single-nucleotide polymorphism (SNP) or gene-level, but a polygenic risk score (PRS) based on the OCD GWAS previously published by the Psychiatric Genetics Consortium (PGC-OCD) was significantly associated with OCS (Pfixed = 3.06 × 10-5). Also, one curated gene set (Mootha Gluconeogenesis) reached Bonferroni-corrected significance (Ngenes = 28, Beta = 0.79, SE = 0.16, Pbon = 0.008). Expression of genes in this set is high at sites of insulin mediated glucose disposal. Dysregulated insulin signaling in the etiology of OCS has been suggested by a previous study describing a genetic overlap of OCS with insulin signaling-related traits in children and adolescents. We report a SNP heritability of 4.1% (P = 0.0044) in the meta-analyzed GWAS, and heritability estimates based on the twin cohorts of 33-43%. Genetic correlation analysis showed that OCS were most strongly associated with OCD (rG = 0.72, p = 0.0007) among all tested psychiatric disorders (N = 11). Of all 97 tested phenotypes, 24 showed a significant genetic correlation with OCS, and 66 traits showed concordant directions of effect with OCS and OCD. OCS have a significant polygenic contribution and share genetic risk with diagnosed OCD, supporting the hypothesis that OCD represents the extreme end of widely distributed OCS in the population.

Practitioner Review: Assessment and treatment of body dysmorphic disorder in young people.

Body dysmorphic disorder (BDD) is a relatively common and highly impairing mental disorder that is strikingly underdiagnosed and undertreated in Child and Adolescent Mental Health Services (CAMHS). The only clinical guidelines for the management of BDD in youth were published nearly 20 years ago, when empirical knowledge was sparse. Fortunately, there has been a surge in research into BDD over the last 10 years, shedding important insights into the phenomenology, epidemiology, assessment and treatment of the disorder in young people. This review aimed to provide an overview of recent research developments of relevance to clinicians and healthcare policymakers. We summarise key findings regarding the epidemiology of BDD in youth, which indicate that the disorder usually develops during teenage years and affects approximately 2% of adolescents at any one point in time. We provide an overview of aetiological research, highlighting that BDD arises from an interplay between genetic and environmental influences. We then focus on screening and assessment strategies, arguing that these are crucial to promote detection and diagnosis of this under-recognised condition. Additionally, we summarise the recommended treatment approaches for BDD in youth, namely cognitive behaviour therapy with or without selective serotonin reuptake inhibitors. The review concludes by highlighting key knowledge gaps and priorities for future research including, but not limited to, better understanding aetiological factors, long-term consequences and treatment.

Efficacy and acceptability of cognitive-behavioral therapy and serotonin reuptake inhibitors for pediatric obsessive-compulsive disorder: a network meta-analysis.

BACKGROUND: Cognitive-behavioral therapy (CBT) and serotonin reuptake inhibitors (SRIs) are recommended treatments for pediatric obsessive-compulsive disorder (OCD), but their relative efficacy and acceptability have not been comprehensively examined. Further, it remains unclear whether the efficacy of in-person CBT is conserved when delivered in other formats, such as over telephone/webcam or as Internet-delivered CBT (ICBT). METHODS: PubMed, PsycINFO, trial registries, and previous systematic reviews were searched for randomized controlled trials (RCTs) comparing CBT (in-person, webcam/telephone-delivered, or ICBT) or SRIs with control conditions or each other. Network meta-analyses were conducted to examine efficacy (post-treatment Children's Yale-Brown Obsessive Compulsive Scale) and acceptability (treatment discontinuation). Confidence in effect estimates was evaluated with CINeMA (Confidence in Network Meta-Analysis). RESULTS: Thirty eligible RCTs and 35 contrasts comprising 2,057 youth with OCD were identified. In-person CBT was significantly more efficacious than ICBT, waitlist, relaxation training, and pill placebo (MD range: 3.95-11.10; CINeMA estimate of confidence: moderate) but did not differ significantly from CBT delivered via webcam/telephone (MD: 0.85 [-2.51, 4.21]; moderate), SRIs (MD: 3.07 [-0.07, 6.20]; low), or the combination of in-person CBT and SRIs (MD: -1.20 [-5.29, 2.91]; low). SRIs were significantly more efficacious than pill placebo (MD: 4.59 [2.70, 6.48]; low) and waitlist (MD: 8.03 [4.24, 11.82]; moderate). No significant differences for acceptability emerged, but confidence in estimates was low. CONCLUSIONS: In-person CBT and SRIs produce clear benefits compared to waitlist and pill placebo and should be integral parts of the clinical management of pediatric OCD, with in-person CBT overall having a stronger evidence base. The combination of in-person CBT and SRIs may be most efficacious, but few studies hinder firm conclusions. The efficacy of CBT appears conserved when delivered via webcam/telephone, while more trials evaluating ICBT are needed.

General somatic health and lifestyle habits in individuals with obsessive- compulsive disorder: an international survey.

BACKGROUND: Obsessive-compulsive disorder (OCD) has been associated with a broad range of health-related issues. Unhealthy lifestyle habits such as physical inactivity, an unhealthy diet, smoking, and alcohol consumption are hypothesized to contribute to this association. However, the lifestyle habits of individuals with OCD have been scarcely investigated. In this international survey, we explored the physical health and lifestyle habits of adults with a self-reported diagnosis of OCD. METHODS: An online global survey available in seven languages was disseminated through interest organizations and social media between July 2021 and March 2022. The survey included questions relating to socio-demographic variables and clinical characteristics (including OCD symptom severity - as measured with the 12-item self-report scale Obsessive-Compulsive Inventory [OCI-12] - and psychotropic medication), physical health, and lifestyle habits. Frequencies and percentages, or means and standard deviations, as appropriate, were calculated. Subgroup analyses by OCD symptom severity, gender, and age group were performed. RESULTS: A total of 496 individuals with OCD completed the survey and were included in the analyses (mean age = 36.0 years, SD = 12.5, range 18-79; 78.8% women). Most participants were from Europe (n = 245, 49.4%) and North America (n = 187, 37.7%). OCD symptom severity scores were on the moderate range (OCI-12 mean score = 21.2, SD = 9.1). A majority (n = 354, 71.4%) reported having comorbid somatic health issues, mainly allergies, gastrointestinal conditions, and cardiometabolic conditions. Nearly half of the sample (n = 236, 47.6%) reported a body mass index ≥ 25, corresponding to at least overweight. A significant proportion of the participants reported low physical activity (n = 271, 55.0%), unhealthy dietary habits (n = 182, 36.7%), risk consumption of alcohol (n = 111, 22.3%), and non-restorative sleep (n = 268, 54.0%). Subgroup analyses showed overall similar results across groups, with some exceptions. CONCLUSIONS: In this sample, individuals with OCD self-reported a range of health-related issues and a number of unhealthy lifestyle behaviors, most prominently a lack of physical activity. Interventions aimed at modifying unhealthy lifestyles to prevent or improve health conditions beyond the psychiatric symptoms should be considered.

Psychometric evaluation of the appearance anxiety inventory in adolescents with body dysmorphic disorder.

The Appearance Anxiety Inventory (AAI) is a self-report measure assessing the typical cognitions and behaviours of body dysmorphic disorder (BDD). Despite its use in research and clinical settings, its psychometric properties have not been evaluated in young people with BDD. We examined the factor structure, reliability, validity, and sensitivity to change of the AAI in 182 youths with BDD (82.9% girls; Mage = 15.56, SD = 1.37) consecutively referred to two specialist outpatient clinics in Stockholm, Sweden (n = 97) and London, England (n = 85). An exploratory factor analysis identified three factors, namely "threat monitoring", "camouflaging", and "avoidance", explaining 48.15% of the variance. The scale showed good internal consistency (McDonalds omega = 0.83) and adequate convergent validity with the Yale-Brown Obsessive-Compulsive Scale Modified for Body Dysmorphic Disorder for Adolescents (BDD-YBOCS-A; rs = 0.42) and the Clinical Global Impression-Severity Scale (rs = 0.32). Sensitivity to change was adequate, with AAI total scores and individual factor scores significantly decreasing over time in the subgroup of participants receiving multimodal treatment for BDD (n = 79). Change of AAI scores over treatment showed a positive statistically significant moderate-to-good correlation (r = 0.55) with changes in BDD symptom severity, measured by the BDD-YBOCS-A. The study provides empirical support for the use of the AAI in young people with BDD in clinical settings.

Genomics of severe and treatment-resistant obsessive-compulsive disorder treated with deep brain stimulation: A preliminary investigation.

Individuals with severe and treatment-resistant obsessive-compulsive disorder (trOCD) represent a small but severely disabled group of patients. Since trOCD cases eligible for deep brain stimulation (DBS) probably comprise the most severe end of the OCD spectrum, we hypothesize that they may be more likely to have a strong genetic contribution to their disorder. Therefore, while the worldwide population of DBS-treated cases may be small (~300), screening these individuals with modern genomic methods may accelerate gene discovery in OCD. As such, we have begun to collect DNA from trOCD cases who qualify for DBS, and here we report results from whole exome sequencing and microarray genotyping of our first five cases. All participants had previously received DBS in the bed nucleus of stria terminalis (BNST), with two patients responding to the surgery and one showing a partial response. Our analyses focused on gene-disruptive rare variants (GDRVs; rare, predicted-deleterious single-nucleotide variants or copy number variants overlapping protein-coding genes). Three of the five cases carried a GDRV, including a missense variant in the ion transporter domain of KCNB1, a deletion at 15q11.2, and a duplication at 15q26.1. The KCNB1 variant (hg19 chr20-47991077-C-T, NM_004975.3:c.1020G>A, p.Met340Ile) causes substitution of methionine for isoleucine in the trans-membrane region of neuronal potassium voltage-gated ion channel KV2.1. This KCNB1 substitution (Met340Ile) is located in a highly constrained region of the protein where other rare missense variants have previously been associated with neurodevelopmental disorders. The patient carrying the Met340Ile variant responded to DBS, which suggests that genetic factors could potentially be predictors of treatment response in DBS for OCD. In sum, we have established a protocol for recruiting and genomically characterizing trOCD cases. Preliminary results suggest that this will be an informative strategy for finding risk genes in OCD.

Early-Life and Family Risk Factors for Tic Disorder Persistence into Adulthood.

BACKGROUND: Many children with tic disorders outgrow their tics, but little is known about the proportion of individuals who will continue to require specialist services in adulthood and which variables are associated with tic persistence. OBJECTIVES: The aims were to estimate the proportion of individuals first diagnosed with tic disorders in childhood who continued to receive tic disorder diagnoses after age 18 years and to identify risk factors for persistence. METHODS: In this Swedish nationwide cohort study including 3761 individuals diagnosed with tic disorders in childhood, we calculated the proportion of individuals whose diagnoses persisted into adulthood. Minimally adjusted logistic regression models examined the associations between sociodemographic, clinical, and family variables and tic disorder persistence. A multivariable model was then fitted, including only variables that were statistically significant in the minimally adjusted models. RESULTS: Seven hundred and fifty-four (20%) children with tic disorders received a diagnosis of a chronic tic disorder in adulthood. Psychiatric comorbidity in childhood (particularly attention-deficit hyperactivity disorder, obsessive-compulsive disorder, pervasive developmental disorders, and anxiety disorders) and psychiatric disorders in first-degree relatives (particularly tic and anxiety disorders) were the strongest risk factors for persistence. We did not observe statistically significant associations with socioeconomic variables, perinatal complications, comorbid autoimmune diseases, or family history of autoimmune diseases. All statistically significant variables combined explained approximately 10% of the variance in tic disorder persistence (P < 0.0001). CONCLUSIONS: Childhood psychiatric comorbidities and family history of psychiatric disorders were the strongest risk factors associated with tic disorder persistence into adulthood. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Maternal suicide attempts and deaths in the first year after cesarean delivery.

BACKGROUND: Cesarean delivery (CD) has been associated with postpartum psychiatric disorders, but less is known about the risk of suicidal behaviors. We estimated the incidence and risk of suicide attempts and deaths during the first postpartum year in mothers who delivered via CD v. vaginally. METHOD: All deliveries in Sweden between 1973 and 2012 were identified. The mothers were followed since delivery for 12 months or until the date of one of the outcomes (i.e. suicide attempt or death by suicide), death by other causes or emigration. Associations were estimated using Cox proportional hazards regression models. RESULTS: Of 4 016 789 identified deliveries, 514 113 (12.8%) were CDs and 3 502 676 (87.2%) were vaginal deliveries. During the 12-month follow-up, 504 (0.098%) suicide attempts were observed in the CD group and 2240 (0.064%) in the vaginal delivery group (risk difference: 0.034%), while 11 (0.0037%) deaths by suicide were registered in the CD group and 109 (0.0029%) in the vaginal delivery group (risk difference: 0.008%). Compared to vaginal delivery, CD was associated with an increased risk of suicide attempts [hazard ratio (HR) 1.46; 95% CI 1.32-1.60], but not of deaths by suicide (HR 1.44; 95% CI 0.88-2.36). CONCLUSIONS: Maternal suicidal behaviors during the first postpartum year were uncommon in Sweden. Compared to vaginal delivery, CD was associated with a small increased risk of suicide attempts, but not death by suicide. Improved understanding of the association between CD and maternal suicidal behaviors may promote more appropriate measures to improve maternal mental well-being and further reduce suicidal risks.

One versus two biological parents with mental disorders: Relationship to educational attainment in the next generation.

BACKGROUND: Both maternal and, separately, paternal mental illness are associated with diminished academic attainment among children. However, the differential impacts of diagnostic type and degree of parental burden (e.g. one v. both parents affected) on these functional outcomes are unknown. METHODS: Using the Swedish national patient (NPR) and multi-generation (MGR) registers, 2 226 451 children (1 290 157 parental pairs), born 1 January 1973-31 December 1997, were followed through 31 December 2013. Diagnostic status of all cohort members was defined for eleven psychiatric disorders, and families classed by exposure: (1) parents affected with any disorder, (2) parents affected with a disorder group (e.g. neuropsychiatric disorders), and (3) parents affected with a specific disorder (e.g. ADHD). Pairs were further defined as 'unaffected,' 'single-affected,', or 'dual-affected.' Among offspring, the study evaluated fulfillment of four academic milestones, from compulsory (primary) school through University (college). Sensitivity analyses considered the impact of child's own mental health, as well as parental education, on main effects. RESULTS: Marked reductions in the odds of achievement were observed, emerging at the earliest levels of schooling for both single-affected [adjusted odds ratio (aOR), 0.50; 95% CI 0.49-0.51] and dual-affected (aOR 0.29, 95% CI 0.28-0.30) pairs and persisting thereafter [aOR range (single), 0.52-0.65; aOR range (dual), 0.30-0.40]. This pattern was repeated for analyses within diagnosis/diagnostic group. Main results were robust to adjustment for offspring mental health and parent education level. CONCLUSIONS: Parental mental illness is associated with profound reductions in educational attainment in the subsequent generation, with children from dual-affected families at uniquely high risk.

Associations of parental and perinatal factors with subsequent risk of stress-related disorders: a nationwide cohort study with sibling comparison.

Little is known about the contribution of pregnancy-related parental and perinatal factors to the development of stress-related disorders. We aimed to investigate whether parental/perinatal adversities entail higher risks of stress-related disorders in the offspring, later in life, by accounting for genetic and early environmental factors. Based on the nationwide Swedish registers, we conducted a population-based cohort study of 3,435,747 singleton births (of which 2,554,235 were full siblings), born 1973-2008 and survived through the age of 5 years. Using both population- and sibling designs, we employed Cox regression to assess the association between parental and perinatal factors with subsequent risk of stress-related disorders. We identified 55,511 individuals diagnosed with stress-related disorders in the population analysis and 37,433 in the sibling analysis. In the population-based analysis we observed increased risks of stress-related disorders among offspring of maternal/paternal age <25, single mothers, parity ≥4, mothers with BMI ≥ 25 or maternal smoking in early pregnancy, gestational diabetes, and offspring born moderately preterm (GA 32-36 weeks), or small-for-gestational-age. These associations were significantly attenuated toward null in the sibling analysis. Cesarean-section was weakly associated with offspring stress-related disorders in population [hazard ratio (HR) 1.09, 95% confidence interval (CI) 1.06-1.12] and sibling analyses (HR 1.10, 95% CI 1.02-1.20). Our findings suggest that most of the observed associations between parental and perinatal factors and risk of stress-related disorders in the population analysis are driven by shared familial environment or genetics, and underscore the importance of family designs in epidemiological studies on the etiology of psychiatric disorders.

Long-term clinical and cost-effectiveness of a therapist-supported online remote behavioural intervention for tics in children and adolescents: extended 12- and 18-month follow-up of a single-blind randomised controlled trial.

BACKGROUND: Little is known about the long-term effectiveness of behavioural therapy for tics. We aimed to assess the long-term clinical and cost-effectiveness of online therapist-supported exposure and response prevention (ERP) therapy for tics 12 and 18 months after treatment initiation. METHODS: ORBIT (online remote behavioural intervention for tics) was a two-arm (1:1 ratio), superiority, single-blind, multicentre randomised controlled trial comparing online ERP for tics with online psychoeducation. The trial was conducted across two Child and Adolescent Mental Health Services in England. Participants were recruited from these two sites, across other clinics in England, or by self-referral. This study was a naturalistic follow-up of participants at 12- and 18-month postrandomisation. Participants were permitted to use alternative treatments recommended by their clinician. The key outcome was the Yale Global Tic Severity Scale Total Tic Severity Score (YGTSS-TTSS). A full economic evaluation was conducted. Registrations are ISRCTN (ISRCTN70758207); ClinicalTrials.gov (NCT03483493). RESULTS: Two hundred and twenty-four participants were enrolled: 112 to ERP and 112 to psychoeducation. The sample was predominately male (177; 79%) and of white ethnicity (195; 87%). The ERP intervention reduced baseline YGTSS-TTSS by 2.64 points (95% CI: -4.48 to -0.79) with an effect size of -0.36 (95% CI: -0.61 to -0.11) after 12 months and by 2.01 points (95% CI: -3.86 to -0.15) with an effect size of -0.27 (95% CI -0.52 to -0.02) after 18 months, compared with psychoeducation. Very few participants (<10%) started new tic treatment during follow-up. The cost difference in ERP compared with psychoeducation was £304.94 (-139.41 to 749.29). At 18 months, the cost per QALY gained was £16,708 for ERP compared with psychoeducation. CONCLUSIONS: Remotely delivered online ERP is a clinical and cost-effective intervention with durable benefits extending for up to 18 months. This represents an efficient public mental health approach to increase access to behavioural therapy and improve outcomes for tics.

Factors associated with long-term benzodiazepine and Z-drug use across the lifespan and 5-year temporal trajectories among incident users: a Swedish nationwide register-based study.

PURPOSE: Despite being discouraged by guidelines, long-term use of benzodiazepines and related Z-drugs (BZDR) remains frequent in the real-world. An improved understanding of factors associated with the transition from new to long-term BZDR use and of temporal BZDR use trajectories is needed. We aimed to assess the proportion of long-term BZDR use (> 6 months) in incident BZDR-recipients across the lifespan; identify 5-year BZDR use trajectories; and explore individual characteristics (demographic, socioeconomic and clinical) and prescribing-related factors (pharmacological properties of the initial BZDR, prescriber's healthcare level, and concurrent dispensing of other medications) associated with long-term BZDR use and distinct trajectories. METHODS: Our nationwide register-based cohort included all BZDR-recipients in Sweden with first dispensation in 2007-2013. Trajectories of BZDR use days per year were built using group-based trajectory modelling. Cox regression and multinomial logistic regression were fitted to assess the predictors of long-term BZDR use and trajectories' membership. RESULTS: In 930,465 incident BZDR-recipients, long-term use increased with age (20.7%, 41.0%, and 57.4% in 0-17, 18-64, and ≥ 65-year-olds, respectively). Four BZDR use trajectories emerged, labelled 'discontinued', 'decreasing', 'slow decreasing' and 'maintained'. The proportion of the 'discontinued' trajectory members was the largest in all ages, but reduced from 75.0% in the youths to 39.3% in the elderly, whereas the 'maintained' increased with age from 4.6% to 36.7%. Prescribing-related factors, in particular multiple BZDRs at initiation and concurrent dispensing of other medications, were associated with increased risks of long-term (vs short-term) BZDR use and developing other trajectories (vs 'discontinued') in all age groups. CONCLUSIONS: The findings highlight the importance of raising awareness and providing support to prescribers to make evidence-based decisions on initiating and monitoring BZDR treatment across the lifespan.

In search of environmental risk factors for obsessive-compulsive disorder: study protocol for the OCDTWIN project.

BACKGROUND: The causes of obsessive-compulsive disorder (OCD) remain unknown. Gene-searching efforts are well underway, but the identification of environmental risk factors is at least as important and should be a priority because some of them may be amenable to prevention or early intervention strategies. Genetically informative studies, particularly those employing the discordant monozygotic (MZ) twin design, are ideally suited to study environmental risk factors. This protocol paper describes the study rationale, aims, and methods of OCDTWIN, an open cohort of MZ twin pairs who are discordant for the diagnosis of OCD. METHODS: OCDTWIN has two broad aims. In Aim 1, we are recruiting MZ twin pairs from across Sweden, conducting thorough clinical assessments, and building a biobank of biological specimens, including blood, saliva, urine, stool, hair, nails, and multimodal brain imaging. A wealth of early life exposures (e.g., perinatal variables, health-related information, psychosocial stressors) are available through linkage with the nationwide registers and the Swedish Twin Registry. Blood spots stored in the Swedish phenylketonuria (PKU) biobank will be available to extract DNA, proteins, and metabolites, providing an invaluable source of biomaterial taken at birth. In Aim 2, we will perform within-pair comparisons of discordant MZ twins, which will allow us to isolate unique environmental risk factors that are in the causal pathway to OCD, while strictly controlling for genetic and early shared environmental influences. To date (May 2023), 43 pairs of twins (21 discordant for OCD) have been recruited. DISCUSSION: OCDTWIN hopes to generate unique insights into environmental risk factors that are in the causal pathway to OCD, some of which have the potential of being actionable targets.

Obsessional jealousy in a community sample: Association with relationship factors, impairment and perceived treatment needs.

OBJECTIVES: Romantic jealousy could be understood as a continuum, from reality-based, transient and functional jealousy to a more chronic form of jealousy with varying insight, intensity and duration. The latter has some overlaps with obsessive-compulsive disorder (here termed obsessional jealousy). Little is known about the nature of obsessional jealousy and its association with functional impairment, perceived negative consequences (drinking, violence), current and past relationship factors (e.g., length of relationship, being in love, infidelity, previous jealousy) or perceived need for professional support. METHODS: Participants were 1076 adults (55% women) who filled in an anonymous survey. RESULTS: Obsessional jealousy, measured with the Obsessional Jealousy Severity Scale, was strongly associated with functional impairment and verbal violence, and more weakly with physical violence and alcohol consumption. Individuals with a history of previous jealousy had more severe symptoms and were more likely to perceive the need for psychological support. Approximately 25% of the sample expressed interest in treatment. CONCLUSIONS: The results suggest that there is a group of individuals with impairing levels of obsessional jealousy who have a perceived need for help with their difficulties. More research is needed on the prevalence and clinical characteristics of these individuals. The development of jealousy-specific psychological models and treatments is warranted.

An online self-guided cognitive intervention for unwanted intrusive thoughts about harming infants in new parents: initial randomised controlled trial with mediation analysis.

Approximately one-fifth of new parents struggle with unwanted intrusive thoughts (UITs) about intentionally harming their child. This study evaluated the initial efficacy, feasibility and acceptability of a novel online self-guided cognitive intervention for new parents with distressing UITs. Self-recruited parents (N = 43, 93% female, age 23-43 years) of children 0-3 years reporting daily distressing and impairing UITs were randomized to the 8-week self-guided online cognitive intervention or to waiting-list. The primary outcome was change on the Parental Thoughts and Behaviour Checklist (PTBC) from baseline to week 8 (post-intervention). The PTBC and negative appraisals (mediator) were assessed at baseline, weekly, post-intervention and at the 1-month follow-up. Results showed that the intervention led to statistically significant reductions in distress and impairment associated with UITs at post-intervention (controlled between-group d = 0.99, 95% CI 0.56 to 1.43), which were maintained at the 1-month follow-up (controlled between-group d = 0.90, 95% CI 0.41 to 1.39). The intervention was deemed to be feasible and acceptable by the participants. Change in negative appraisals mediated reductions in UITs but the model was sensitive to mediator-outcome confounders. We conclude that this novel online self-guided cognitive intervention can potentially reduce the distress and impairment associated with UITs in new parents. Large-scale trials are warranted.Abbreviations: UITs: Unwanted Intrusive Thoughts PTBC: Parental Thoughts and Behaviour Checklist.

The Cost of Obsessive-Compulsive Disorder in Swedish Youth.

The economic impact of pediatric obsessive-compulsive disorder (OCD) on society is unknown. We compared a wide range of individual-level cost data of children 7-17 years with OCD (n = 152) with a control group from the general population in Sweden (n = 768). The total annual cost in the OCD group was M = 11941€ (95%CI [9915-13966]), compared to the control group M = 6380 € (95%CI [5461-7299]), corresponding to an estimated marginal mean cost of OCD of 5560 € per person and year (z = 4.99, p < .001). OCD was associated with significantly higher healthcare costs, parental absence from work and school productivity loss. OCD symptom severity was positively associated with higher costs. The total societal burden of pediatric OCD in Sweden was estimated to be 94.3 € million per year (95%CI [56.9-131.8]). These results have important implications for policy makers and for the allocation of healthcare resources. Similar studies are needed in other countries in order to estimate the global cost of the disorder.

Psychometric Evaluation of the Yale-Brown Obsessive-Compulsive Scale Modified for Body Dysmorphic Disorder for Adolescents (BDD-YBOCS-A).

The Yale-Brown Obsessive-Compulsive Scale Modified for Body Dysmorphic Disorder for Adolescents (BDD-YBOCS-A) is a clinician-rated measure of BDD symptom severity in youth. Despite widespread use in both research and clinical practice, its psychometric properties have not been formally evaluated. The current study examined the factor structure, reliability, validity, and sensitivity to change of the BDD-YBOCS-A in 251 youths with BDD attending two specialist clinics. A principal component analysis identified two factors, explaining 56% of the variance. The scale showed good internal consistency (Cronbach's alpha = 0.87) and adequate convergent and divergent validity. In a subgroup of participants receiving BDD treatment (n = 175), BDD-YBOCS-A scores significantly decreased over time, demonstrating sensitivity to change. BDD-YBOCS-A change scores over treatment were highly correlated with severity changes measured by the Clinical Global Impression - Severity scale (r = .84). The study provides empirical support for the use of the BDD-YBOCS-A in children and adolescents with BDD.

The COVID-19 pandemic and its impact on tic symptoms in children and young people: a prospective cohort study.

To understand how children and young people with tic disorders were affected by COVID-19, we compared pre and during pandemic scores on the Yale Global Tic Severity Scale (YGTSS). Participants were young people (N = 112; male:78%; 9-17 years) randomised to the control arm of the "ORBIT-Trial" (ISRCTN70758207, ClinicalTrials.gov-NCT03483493). For this analysis, the control arm was split into two groups: one group was followed up to 12-months' post-randomisation before the pandemic started (pre-COVID group, n = 44); the other group was impacted by the pandemic at the 12-month follow-up (during-COVID group, n = 47). Mixed effects linear regression modelling was conducted to explore differences in YGTSS at 6- and 12-months post-randomisation. There were no significant differences in tic symptom or severity between participants who were assessed before and during COVID-19. This finding was not influenced by age, gender, symptoms of anxiety or autism spectrum disorder. Thus, the COVID-19 pandemic did not significantly impact existing tic symptoms.

An overview of the first 5 years of the ENIGMA obsessive-compulsive disorder working group: The power of worldwide collaboration.

Neuroimaging has played an important part in advancing our understanding of the neurobiology of obsessive-compulsive disorder (OCD). At the same time, neuroimaging studies of OCD have had notable limitations, including reliance on relatively small samples. International collaborative efforts to increase statistical power by combining samples from across sites have been bolstered by the ENIGMA consortium; this provides specific technical expertise for conducting multi-site analyses, as well as access to a collaborative community of neuroimaging scientists. In this article, we outline the background to, development of, and initial findings from ENIGMA's OCD working group, which currently consists of 47 samples from 34 institutes in 15 countries on 5 continents, with a total sample of 2,323 OCD patients and 2,325 healthy controls. Initial work has focused on studies of cortical thickness and subcortical volumes, structural connectivity, and brain lateralization in children, adolescents and adults with OCD, also including the study on the commonalities and distinctions across different neurodevelopment disorders. Additional work is ongoing, employing machine learning techniques. Findings to date have contributed to the development of neurobiological models of OCD, have provided an important model of global scientific collaboration, and have had a number of clinical implications. Importantly, our work has shed new light on questions about whether structural and functional alterations found in OCD reflect neurodevelopmental changes, effects of the disease process, or medication impacts. We conclude with a summary of ongoing work by ENIGMA-OCD, and a consideration of future directions for neuroimaging research on OCD within and beyond ENIGMA.

Insomnia in Tourette Syndrome and Chronic Tic Disorder.

BACKGROUND: Insomnia is common in Tourette syndrome (TS) and chronic tic disorder (CTD), but precise prevalence estimates are lacking. OBJECTIVE: In this Swedish register-based cohort study, we estimated the prevalence of insomnia in TS/CTD and quantified the magnitude of this association, accounting for familial confounders and relevant somatic and psychiatric comorbidities. METHODS: Of 10,444,702 individuals living in Sweden during the period from 1997 to 2013, 5877 had a diagnosis of TS/CTD and were compared to unexposed individuals from the general population on the presence of insomnia using logistic regression models. RESULTS: Individuals with TS/CTD had a period prevalence of insomnia of 32.16%, compared to 13.70% of the unexposed population. This translated into a 6.7-fold increased likelihood of insomnia in TS/CTD (odds ratio adjusted [aOR] for sex, birth year, birth country, and somatic disorders = 6.74; 95% confidence interval [CI], 6.37-7.15). A full sibling comparison, designed to adjust for shared familial factors, attenuated the estimates (aOR = 5.41; 95% CI, 4.65-6.30). When individuals with attention-deficit/hyperactivity disorder (ADHD) and pervasive developmental disorders were excluded, the association was also attenuated, whereas exclusion of other psychiatric comorbidities had minimal impact. Having persistent TS/CTD, comorbid ADHD, and taking ADHD medication greatly increased the likelihood of insomnia. CONCLUSIONS: Insomnia is significantly associated with TS/CTD, independently from somatic disorders, familial factors or psychiatric comorbidities, although familial factors, neurodevelopmental comorbidities, and ADHD/ADHD medication may explain part of the association. Insomnia should be routinely assessed and managed in TS/CTD, particularly in chronic patients and in those with comorbid ADHD. Other sleep disorders require further study. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.