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.

Exploring the feasibility and acceptance of huddinge online prolonged exposure therapy (HOPE) for severe and complex PTSD.

Background: Trauma-focused cognitive behavioural therapy such as prolonged exposure is considered firsthand choice for treatment of posttraumatic stress disorder (PTSD) but is seldom available in regular care. Digital therapy is proposed to bridge this gap, but its effectiveness for severe and complex PTSD is uncertain. The primary objective of the current study was to examine the feasibility, acceptability, and preliminary effects of digital therapist-guided prolonged exposure (Huddinge Online Prolonged Exposure; HOPE).Method: Thirty participants with moderate to severe PTSD, with the majority self-reporting complex PTSD symptoms, received HOPE over a ten-week period. Eighty percent of participants had been diagnosed with other psychiatric comorbidity by a mental health professional. Primary outcome was the feasibility and acceptability of treatment. Participants were repeatedly assessed using clinician- and self-rated outcome measures at baseline, during the treatment period, post-treatment, and at 1-month and 6-month follow-ups to estimate preliminary treatment effects. The Clinician Administered PTSD Scale version 5 (CAPS-5), administered by independent assessors, evaluated PTSD symptom severity.Results: HOPE proved feasible and effective, delivering evidence-based treatment content in a psychiatric outpatient setting with reduced therapist time. The treatment was well-tolerated, with no severe adverse events and a 17% dropout rate. Sixty-four percent completed the exposure-based portion of the treatment, and overall satisfaction measured by the Client Satisfaction Questionnaire was moderate. Furthermore, significant reductions in PTSD symptoms as assessed with the CAPS-5 (Cohen's d = 1.30 [95% CI -1.79 to -0.82]) at the primary endpoint 1 month which were sustained at the 6-month follow up.Conclusion: Altogether, this study indicate feasibility of treating severe and complex PTSD through a digital PE intervention, thereby building upon and extending previous research findings. Large-scale controlled trials are needed to further validate the specific effect and long-term benefits of HOPE.Trial registration: ClinicalTrials.gov identifier: NCT05560854.

HOPE, a digital therapist-guided prolonged exposure programme, demonstrated feasibility and preliminary effects for severe and complex PTSD in a psychiatric outpatient setting, while requiring less therapist time.HOPE was well-tolerated by participants, with a relatively low dropout rate and average overall satisfaction.Significant reductions in PTSD symptoms were observed, and these benefits were sustained at the 6-month follow-up.

All-Cause and Cause-Specific Mortality Among Individuals With Hypochondriasis.

Importance: Hypochondriasis, also known as health anxiety disorder, is a prevalent, yet underdiagnosed psychiatric disorder characterized by persistent preoccupation about having serious and progressive physical disorders. The risk of mortality among individuals with hypochondriasis is unknown. Objective: To investigate all-cause and cause-specific mortality among a large cohort of individuals with hypochondriasis. Design, Setting, and Participants: This Swedish nationwide matched-cohort study included 4129 individuals with a validated International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) diagnosis of hypochondriasis assigned between January 1, 1997, and December 31, 2020, and 41 290 demographically matched individuals without hypochondriasis. Individuals with diagnoses of dysmorphophobia (body dysmorphic disorder) assigned during the same period were excluded from the cohort. Statistical analyses were conducted between May 5 and September 27, 2023. Exposure: Validated ICD-10 diagnoses of hypochondriasis in the National Patient Register. Main Outcome and Measures: All-cause and cause-specific mortality in the Cause of Death Register. Covariates included birth year, sex, county of residence, country of birth (Sweden vs abroad), latest recorded education, civil status, family income, and lifetime psychiatric comorbidities. Stratified Cox proportional hazards regression models were used to estimate the hazard ratios (HRs) and 95% CIs of all-cause and cause-specific mortality. Results: Of the 4129 individuals with hypochondriasis (2342 women [56.7%]; median age at first diagnosis, 34.5 years [IQR, 26.3-46.1 years]) and 41 290 demographically matched individuals without hypochondriasis (23 420 women [56.7%]; median age at matching, 34.5 years [IQR, 26.4-46.2 years]) in the study, 268 individuals with hypochondriasis and 1761 individuals without hypochondriasis died during the study period, corresponding to crude mortality rates of 8.5 and 5.5 per 1000 person-years, respectively. In models adjusted for sociodemographic variables, an increased rate of all-cause mortality was observed among individuals with hypochondriasis compared with individuals without hypochondriasis (HR, 1.69; 95% CI, 1.47-1.93). An increased rate was observed for both natural (HR, 1.60; 95% CI, 1.38-1.85) and unnatural (HR, 2.43; 95% CI, 1.61-3.68) causes of death. Most deaths from unnatural causes were attributed to suicide (HR, 4.14; 95% CI, 2.44-7.03). The results were generally robust to additional adjustment for lifetime psychiatric disorders. Conclusions and Relevance: This cohort study suggests that individuals with hypochondriasis have an increased risk of death from both natural and unnatural causes, particularly suicide, compared with individuals from the general population without hypochondriasis. Improved detection and access to evidence-based care should be prioritized.

Study protocol for a single-blind, parallel-group, randomised, controlled non-inferiority trial of 4-day intensive versus standard cognitive behavioural therapy for adults with obsessive-compulsive disorder.

INTRODUCTION: Individual cognitive behavioural therapy (CBT) with exposure and response prevention is an effective treatment for obsessive-compulsive disorder (OCD). However, individual CBT is costly and time-consuming, requiring weekly therapy sessions for 3-4 months. A 4-day intensive version of CBT for OCD delivered in group format has been recently developed in Norway (Bergen 4-day treatment, B4DT). B4DT has shown promising results in several uncontrolled and one small, randomised trial, but its non-inferiority to the gold standard treatment has not been established. METHODS AND ANALYSIS: This single-blind, randomised controlled trial including 120 patients (60 per arm) will compare B4DT to individual CBT. The primary outcome is the blind assessor-rated Yale-Brown Obsessive Compulsive Scale (Y-BOCS). We hypothesise that B4DT will be non-inferior to gold standard CBT 15 weeks after treatment start. The non-inferiority margin is set at four points on the Y-BOCS. Secondary outcomes include time to treatment response, cost-effectiveness, response and remission rates, drop-out rates and adverse events. ETHICS AND DISSEMINATION: This study has been approved by the Swedish Ethical Review Authority. Hypotheses were specified and analysis code published before data collection started. Results from all analyses will be reported in accordance with the Consolidated Standards of Reporting Trials statement for non-pharmacological trials and Consolidated Health Economic Evaluation Reporting Standards irrespective of outcome. TRIAL REGISTRATION NUMBER: NCT05608278.

Brief digital self-care intervention for health anxiety in a Swedish Medical University Clinic: a prospective single-group feasibility study.

OBJECTIVES: In routine psychiatric care in Stockholm, Sweden, a comprehensive therapist-guided intervention for clinically significant health anxiety is implemented. However, there is a need for more easily accessible self-care interventions to improve treatment dissemination. This study aimed to transform an existing therapist-guided digital intervention into a self-care intervention, reducing patient burden and used clinical resources while maintaining quality and safety. DESIGN: An uncontrolled feasibility study. SETTING: Conducted at Karolinska Institutet, a medical university in Sweden, with nationwide recruitment trough online advertisements. PARTICIPANTS: Twenty-five adults used the self-care intervention and underwent telephone assessments, along with completing self-rated questionnaires. INTERVENTION: The newly developed 8-week self-care intervention was designed to be user-friendly without therapist guidance, and to facilitate high levels of behavioural engagement. PRIMARY AND SECONDARY OUTCOME MEASURES: Indicators of quality and safety, including changes in health anxiety severity (primary), clinician time, participant adherence, perceived credibility/satisfaction with the intervention and adverse events, were benchmarked against a previous study of the more comprehensive intervention it was based on. RESULTS: Compared with the original guided intervention, the self-care intervention was condensed in terms of text (up to 70% less reading), duration (8 weeks instead of 12) and number of exercises. Quality indicators were similar to the original version. Most participants worked actively with core components in the self-care intervention. Within-group effects on health anxiety from pretreatment to the 3-month follow-up were large (g=1.37; 95% CI 0.74 to 2.00). No serious adverse events were reported. CONCLUSIONS: This brief digital self-care intervention shows potential for increasing access to treatment for individuals with health anxiety while reducing the burden on patients and clinical resources. Future studies should investigate the optimal type of intervention and support for different individuals, and if non-inferiority can be established. TRIAL REGISTRATION NUMBER: NCT05446766.

Study protocol for a randomized controlled trial of in-home decluttering augmentation of group cognitive-behavioral therapy for hoarding disorder: the Joining Forces Trial.

BACKGROUND: Cognitive behavioral therapy (CBT) is a moderately efficacious treatment for hoarding disorder (HD), with most individuals remaining symptomatic after treatment. The Joining Forces Trial will evaluate whether 10 weeks of in-home decluttering can significantly augment the outcomes of group CBT. METHODS: A randomized controlled trial of in-home decluttering augmentation of group CBT for HD. Adult participants with HD (N = 90) will receive 12 weeks of protocol-based group CBT for HD. After group CBT, participants will be randomized to either 10 weeks of in-home decluttering led by a social services team or a waitlist. The primary endpoint is 10 weeks post-randomization. The primary outcome measures are the self-reported Saving Inventory-Revised and the blind assessor-rated Clutter Image Rating. Participants on the waitlist will cross over to receive the in-home decluttering intervention after the primary endpoint. Data will be analyzed according to intention-to-treat principles. We will also evaluate the cost-effectiveness of this intervention from both healthcare and societal perspectives. DISCUSSION: HD is challenging to treat with conventional psychological treatments. We hypothesize that in-home decluttering sessions carried out by personnel in social services will be an efficacious and cost-effective augmentation strategy of group CBT for HD. Recruitment started in January 2021, and the final participant is expected to reach the primary endpoint in December 2024. TRAIL REGISTRATION: ClinicalTrials.gov NCT04712474. Registered on 15 January 2021.

Executive functioning in body dysmorphic disorder and obsessive-compulsive disorder.

OBJECTIVE: To assess executive functions (EFs) in patients with body dysmorphic disorder (BDD) and obsessive-compulsive disorder (OCD) compared with healthy controls. METHODS: Adults diagnosed with BDD (n = 26) or OCD (n = 29) according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and healthy controls (n = 28) underwent validated and computerized neuropsychological tests, spatial working memory (SWM), intra-extra-dimensional set shifting (IED), and stop signal task (SST), from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Test performance was compared between groups, and correlated with standardized symptom severity of BDD and OCD. Significance level was set to P < .05. RESULTS: There were no statistically significant between-group differences on key outcome measures in SWM, IED, or SST. There was a weak positive correlation between symptom severity and test errors on SWM and IED in both OCD and BDD groups; increased clinical severity was associated with more errors in these tests. Furthermore, there was a negative correlation between symptom severity and SST in the BDD group. CONCLUSIONS: Patients with BDD or OCD did not differ from healthy control subjects in terms of test performance; however, there were several statistically significant correlations between symptom severity and performance in those with BDD or OCD. More studies on EFs in BDD and OCD are required to elucidate if there are differences in EFs between these two disorders.

Meta-analysis of genome-wide association studies of hoarding symptoms in 27,537 individuals.

Hoarding Disorder (HD) is a mental disorder characterized by persistent difficulties discarding or parting with possessions, often resulting in cluttered living spaces, distress, and impairment. Its etiology is largely unknown, but twin studies suggest that it is moderately heritable. In this study, we pooled phenotypic and genomic data from seven international cohorts (N = 27,537 individuals) and conducted a genome wide association study (GWAS) meta-analysis of parent- or self-reported hoarding symptoms (HS). We followed up the results with gene-based and gene-set analyses, as well as leave-one-out HS polygenic risk score (PRS) analyses. To examine a possible genetic association between hoarding symptoms and other phenotypes we conducted cross-trait PRS analyses. Though we did not report any genome-wide significant SNPs, we report heritability estimates for the twin-cohorts between 26-48%, and a SNP-heritability of 11% for an unrelated sub-cohort. Cross-trait PRS analyses showed that the genetic risk for schizophrenia and autism spectrum disorder were significantly associated with hoarding symptoms. We also found suggestive evidence for an association with educational attainment. There were no significant associations with other phenotypes previously linked to HD, such as obsessive-compulsive disorder, depression, anxiety, or attention-deficit hyperactivity disorder. To conclude, we found that HS are heritable, confirming and extending previous twin studies but we had limited power to detect any genome-wide significant loci. Much larger samples will be needed to further extend these findings and reach a "gene discovery zone". To move the field forward, future research should not only include genetic analyses of quantitative hoarding traits in larger samples, but also in samples of individuals meeting strict diagnostic criteria for HD, and more ethnically diverse samples.

The 14-item short health anxiety inventory (SHAI-14) used as a screening tool: appropriate interpretation and diagnostic accuracy of the Swedish version.

BACKGROUND: The 14-item Short Health Anxiety Inventory (SHAI-14) is a common measure of health anxiety but its screening properties have not been studied. The aims of this study were to evaluate the SHAI-14 as a screening instrument, identify cut-offs for clinically significant health anxiety and investigate which scores correspond to different severity levels. METHOD: The study included 1729 psychiatric patients and 85 healthy controls. Participants completed the SHAI-14 and underwent a diagnostic interview. Cut-off scores were evaluated in three scenarios to approximate screening 1) in a psychiatric clinic, 2) in a low prevalence setting and, 3) of healthy volunteers (cut-off for remission). Receiver operating characteristics were used. Classification of severity was based on the distribution of SHAI-14 scores reported by patients with clinically significant health anxiety. RESULTS: The area under the curve (AUC) values were high in all scenarios (above 0.95). The optimal cut-off scores on the SHAI-14 were 22 in the psychiatric context, 29 in a setting with low prevalence of psychiatric disorders and 18 versus healthy controls. SHAI-14 scores of 0-27 represented no or mild health anxiety, 28-32 moderate health anxiety and 33-42 substantial health anxiety. CONCLUSION: Brief self-report measures used as screening instruments are a simple way of gathering information about the presence of specific symptoms and thus a way to detect the likelihood of a diagnosis. The SHAI-14 shows evidence of good diagnostic utility in both clinical and non-clinical settings. However, which cut-off score is to be used, depends on the intended purpose and the setting where the cut-off is used.

Internet-delivered acceptance-based behavior therapy for trichotillomania and skin-picking disorder in a psychiatric setting: A feasibility trial.

Trichotillomania (TTM) and skin-picking disorder (SPD) are two clinically related conditions that can be successfully treated with behavior therapy (BT). There is some research indicating that BT for TTM and SPD can be efficacious also when delivered online instead of face-to-face, however, previous studies have mainly used self-recruited samples in a university context and it is unclear if the effects of online BT also extend to regular psychiatric patients. The current study set out to investigate if internet-delivered BT (I-BT) is a feasible, acceptable and preliminarily efficacious treatment for patients in a routine psychiatric setting. Twenty-five adult clinician-referred patients with TTM (n = 7) and/or SPD (n = 18) received 10 weeks of therapist-guided I-BT. The I-BT program incorporated both traditional interventions (e.g. habit reversal) as well as more recent acceptance-based techniques (e.g. embracing the urges and mindfulness). Clinician- and self-rated outcomes were assessed at pretreatment, posttreatment and at the delivery of 4 additional booster modules. Results showed that the majority of the participants were satisfied with the treatment and found it credible. The average number of completed internet modules was 7.2/10; five participants ended treatment prematurely. Significant decreases in hair pulling and skin picking severity were demonstrated from pretreatment to posttreatment with within-group effect sizes ranging from d = 0.89 to 1.75. The results remained significant up to the 12-month follow-up on most outcome measures. Altogether, the results provide initial evidence suggesting that I-BT could be a feasible, acceptable and potentially effective treatment for TTM and SPD for patients in a regular psychiatric setting.

Effect of Internet-Based vs Face-to-Face Cognitive Behavioral Therapy for Adults With Obsessive-Compulsive Disorder: A Randomized Clinical Trial.

Importance: Cognitive behavioral therapy (CBT) for obsessive-compulsive disorder (OCD) is a highly specialized treatment that is in short supply worldwide. Objectives: To investigate whether both therapist-guided and unguided internet-based CBT (ICBT) are noninferior to face-to-face CBT for adults with OCD, to conduct a health economic evaluation, and to determine whether treatment effects were moderated by source of participant referral. Design, Setting, and Participants: This study is a single-blinded, noninferiority, randomized clinical trial, with a full health economic evaluation, conducted between September 2015 and January 2020, comparing therapist-guided ICBT, unguided ICBT, and individual face-to-face CBT for adults with OCD. Follow-up data were collected up to 12 months after treatment. The study was conducted at 2 specialist outpatient OCD clinics in Stockholm, Sweden. Participants included a consecutive sample of adults with a primary diagnosis of OCD, either self-referred or referred by a clinician. Data analysis was performed from June 2019 to January 2022. Interventions: Guided ICBT, unguided ICBT, and face-to-face CBT delivered over 14 weeks. Main Outcomes and Measures: The primary end point was the change in OCD symptom severity from baseline to 3-month follow-up. The noninferiority margin was 3 points on the masked assessor-rated Yale-Brown Obsessive Compulsive Scale. Results: A total of 120 participants were enrolled (80 women [67%]; mean [SD] age, 32.24 [9.64] years); 38 were randomized to the face-to-face CBT group, 42 were randomized to the guided ICBT group, and 40 were randomized to the unguided ICBT group. The mean difference between therapist-guided ICBT and face-to-face CBT at the primary end point was 2.10 points on the Yale-Brown Obsessive Compulsive Scale (90% CI, -0.41 to 4.61 points; P = .17), favoring face-to-face CBT, meaning that the primary noninferiority results were inconclusive. The difference between unguided ICBT and face-to-face CBT was 5.35 points (90% CI, 2.76 to 7.94 points; P < .001), favoring face-to-face CBT. The health economic analysis showed that both guided and unguided ICBT were cost-effective compared with face-to-face CBT. Source of referral did not moderate treatment outcome. The most common adverse events were anxiety (30 participants [25%]), depressive symptoms (20 participants [17%]), and stress (11 participants [9%]). Conclusions and Relevance: The findings of this randomized clinical trial of ICBT vs face-to-face CBT for adults with OCD do not conclusively demonstrate noninferiority. Therapist-guided ICBT could be a cost-effective alternative to in-clinic CBT for adults with OCD in scenarios where traditional CBT is not readily available; unguided ICBT is probably less efficacious but could be an alternative when providing remote clinician support is not feasible. Trial Registration: ClinicalTrials.gov Identifier: NCT02541968.

Validity and reliability of the diagnostic codes for hypochondriasis and dysmorphophobia in the Swedish National Patient Register: a retrospective chart review.

OBJECTIVES: In the International Classification of Diseases, Tenth Edition (ICD-10), hypochondriasis (illness anxiety disorder) and dysmorphophobia (body dysmorphic disorder) share the same diagnostic code (F45.2). However, the Swedish ICD-10 allows for these disorders to be coded separately (F45.2 and F45.2A, respectively), potentially offering unique opportunities for register-based research on these conditions. We assessed the validity and reliability of their ICD-10 codes in the Swedish National Patient Register (NPR). DESIGN: Retrospective chart review. METHODS: Six hundred individuals with a diagnosis of hypochondriasis or dysmorphophobia (300 each) were randomly selected from the NPR. Their medical files were requested from the corresponding clinics, located anywhere in Sweden. Two independent raters assessed each file according to ICD-10 definitions and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision and Fifth Edition criteria. Raters also completed the Clinical Global Impression-Severity (CGI-S) and the Global Assessment of Functioning (GAF). PRIMARY OUTCOME MEASURE: Per cent between-rater agreement and positive predictive value (PPV). Intraclass correlation coefficients for the CGI-S and the GAF. RESULTS: Eighty-four hypochondriasis and 122 dysmorphophobia files were received and analysed. The inter-rater agreement rate regarding the presence or absence of a diagnosis was 95.2% for hypochondriasis and 92.6% for dysmorphophobia. Sixty-seven hypochondriasis files (79.8%) and 111 dysmorphophobia files (91.0%) were considered 'true positive' cases (PPV=0.80 and PPV=0.91, respectively). CGI-S scores indicated that symptoms were moderately to markedly severe, while GAF scores suggested moderate impairment for hypochondriasis cases and moderate to serious impairment for dysmorphophobia cases. CGI-S and GAF inter-rater agreement were good for hypochondriasis and moderate for dysmorphophobia. CONCLUSIONS: The Swedish ICD-10 codes for hypochondriasis and dysmorphophobia are sufficiently valid and reliable for register-based studies. The results of such studies should be interpreted in the context of a possible over-representation of severe and highly impaired cases in the register, particularly for dysmorphophobia.

ACT-enhanced group behavior therapy for trichotillomania and skin-picking disorder: A feasibility study.

OBJECTIVE: To evaluate the feasibility and efficacy of ACT-enhanced Group Behavior Therapy (AEGBT) for mixed diagnosis groups including patients with trichotillomania (TTM) and skin-picking disorder (SPD) in routine psychiatric care. METHOD: Adult patients (N = 40) with TTM and/or SPD received 10 weeks of AEGBT followed by five booster sessions. The primary outcome measure for TTM was the Massachusetts General Hospital Hairpulling Scale (MGH-HPS) and for SPD the Skin Picking Scale-Revised (SPS-R), assessed at posttreatment and at booster sessions. RESULTS: Results showed significant reductions in hair pulling and skin-picking severity from baseline to posttreatment and large effect sizes at posttreatment. Improvements remained significant at the 12-month follow-up for patients with SPD, but not for patients with TTM. Group attendance was high and few patients dropped out from treatment. The group format enabled therapists to see 25% more patients compared with an individual format. CONCLUSION: The results provide initial support for the feasibility and efficacy of an adapted treatment approach for TTM and SPD.

The developmental origins of hoarding disorder in adolescence: a longitudinal clinical interview study following an epidemiological survey.

Hoarding disorder (HD) is hypothesized to originate in childhood/adolescence but little is known about the presentation of hoarding symptoms in youth and their natural history. In this longitudinal study, we tracked and conducted in-depth psychiatric interviews with twins who participated in an epidemiological survey and screened positive on a measure of hoarding symptoms at age 15. Twins screening positive for clinically significant hoarding symptoms at age 15 (n = 42), their co-twins (n = 33), a group of screen negative twins (n = 49), and their parents underwent a clinical assessment a median of 3 years after the initial screening. The assessment included psychiatric screening, hoarding symptoms and cognitions, in-home or photographic assessment of clutter levels, parental accommodation and familial burden. None of the participants had significant levels of clutter at follow-up and thus did not meet strict criteria for HD. However, twins meeting partial criteria (i.e., DSM-5 criteria A and B) for HD (n = 28) had more psychiatric disorders and scored significantly higher on all measures of hoarding symptoms including researcher-rated levels of clutter in their homes, compared to twins who did not meet partial criteria for HD (n = 46). As currently defined in DSM-5, HD may be rare in young people. A non-negligible proportion of young people who were screen positive on hoarding symptoms at age 15 had substantial hoarding symptoms and other psychopathology at follow-up. Whether and how many of these individuals will develop full-blown HD is unknown but the results offer unique insights about the probable origins of HD in adolescence.

Targeting excessive worry with internet-based extinction therapy: a randomised controlled trial with mediation analysis and economical evaluation.

BACKGROUND: Excessive worry is a common phenomenon. Our research group has previously developed an online intervention for excessive worry based on operant principles of extinction (IbET; internet-based extinction therapy) and tested it against a waiting-list. The aim of this study was to evaluate IbET against an active control comparator (CTRL). METHODS: A 10-week parallel participant blind randomised controlled trial with health-economical evaluation and mediation analyses. Participants (N = 311) were randomised (ratio 4.5:4.5:1) to IbET, to CTRL (an internet-based stress-management training program) or to waiting-list. The nation-wide trial included self-referred adults with excessive worry. The primary outcome was change in worry assessed with the Penn State Worry Questionnaire from baseline to 10 weeks. RESULTS: IbET had greater reductions in worry compared to CTRL [-3.6 point difference, (95% CI -2.4 to -4.9)] and also a significantly larger degree of treatment responders [63% v. 51%; risk ratio = 1.24 (95% CI 1.01-1.53)]. Both IbET and CTRL made large reductions in worry compared to waiting-list and effects were sustained up to 1 year. Treatment credibility, therapist attention, compliance and working alliance were equal between IbET and CTRL. Data attrition was 4% at the primary endpoint. The effects of IbET were mediated by the hypothesized causal mechanism (reduced thought suppression) but not by competing mediators. Health-economical evaluation indicated that IbET had a 99% chance of being cost-effective compared to CTRL given societal willingness to pay of 1000€. CONCLUSIONS: IbET is more effective than active comparator to treat excessive worry. Replication and extensions to real-world setting are warranted.

Sudden Gains in Internet-Based Cognitive Behavior Therapy for Body Dysmorphic Disorder.

Sudden gains have been associated with better short- and long-term treatment outcomes in a number of psychiatric disorders. However, no studies to date have evaluated sudden gains in body dysmorphic disorder (BDD). We used data from a previous randomized controlled trial evaluating the efficacy of an Internet-based cognitive-behavior treatment (CBT) for BDD. The sample consisted of 47 adults diagnosed with BDD. We compared the treatment outcomes of sudden gainers vs. gradual gainers (i.e., treatment responders with no sudden gains) and non-sudden gainers (i.e., gradual gainers plus nonresponders) at posttreatment and 3, 12, and 24 months after the end of the treatment. Twelve (25.5%) participants experienced a sudden gain. Compared to non-sudden gainers and to gradual gainers, sudden gainers showed significantly larger improvements on the Yale-Brown Obsessive-Compulsive Scale modified for BDD at posttreatment (g = 1.23 and g = .91, respectively), and at 3-month (g = 1.23 and g = 1.00, respectively), 12-month (g = 1.12 and g = .91, respectively), and 24-month follow-up (g = 1.11 and g = .97, respectively). This translated into higher rates of treatment responders and remitters in the sudden gainers across all time points. The occurrence of sudden gains in Internet-based CBT for BDD is associated with favorable short- and long-term treatment outcomes. This suggests that a sudden improvement during the treatment could be a marker of good prognosis, while non-sudden-including gradual-gainers are more likely to need continued support or booster sessions. Early identification of patients who are not progressing as expected and subsequent tailoring of the delivered intervention has the potential to improve treatment outcomes in this group.

Predictors of remission from body dysmorphic disorder after internet-delivered cognitive behavior therapy: a machine learning approach.

BACKGROUND: Previous attempts to identify predictors of treatment outcomes in body dysmorphic disorder (BDD) have yielded inconsistent findings. One way to increase precision and clinical utility could be to use machine learning methods, which can incorporate multiple non-linear associations in prediction models. METHODS: This study used a random forests machine learning approach to test if it is possible to reliably predict remission from BDD in a sample of 88 individuals that had received internet-delivered cognitive behavioral therapy for BDD. The random forest models were compared to traditional logistic regression analyses. RESULTS: Random forests correctly identified 78% of participants as remitters or non-remitters at post-treatment. The accuracy of prediction was lower in subsequent follow-ups (68, 66 and 61% correctly classified at 3-, 12- and 24-month follow-ups, respectively). Depressive symptoms, treatment credibility, working alliance, and initial severity of BDD were among the most important predictors at the beginning of treatment. By contrast, the logistic regression models did not identify consistent and strong predictors of remission from BDD. CONCLUSIONS: The results provide initial support for the clinical utility of machine learning approaches in the prediction of outcomes of patients with BDD. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02010619.

Long-term outcome of therapist-guided internet-based cognitive behavioural therapy for body dysmorphic disorder (BDD-NET): a naturalistic 2-year follow-up after a randomised controlled trial.

OBJECTIVES: Most patients with body dysmorphic disorder (BDD) do not receive evidence-based treatment. A randomised controlled trial (RCT) has found that a therapist-guided internet-based cognitive-behavioural therapy (CBT) programme for BDD (BDD-NET) can be delivered safely via the internet with significant improvements in BDD symptom severity in the short term. The purpose of this study was to evaluate if the therapeutic gains of BDD-NET are maintained 2 years after treatment. SETTING: Academic medical centre. PARTICIPANTS: A naturalistic 2-year follow-up study of the 88 self-referred adult outpatients with a diagnosis of BDD that had received BDD-NET within the context of the RCT. PRIMARY AND SECONDARY OUTCOMES: The primary outcome was the BDD-Yale-Brown Obsessive-Compulsive Scale (YBOCS). Responder status was defined as a ≥30% reduction in symptoms. Remission was defined as no longer meeting Diagnostic and Statistical Manual of Mental Disorders 5th edition criteria for BDD. Secondary outcomes included measures of depression, global functioning and quality of life. RESULTS: The efficacy of BDD-NET was sustained long- term, with further improvements observed on the BDD-YBOCS during the follow-up period. At follow-up, 69% (95% CI 57% to 80%) were classified as responders and 56% (95% CI 43% to 69%) were in remission. Gains on depressive symptoms and global functioning were also sustained but not quality of life. A majority of participants reported that the main reason for seeking help for their BDD was the possibility to access the treatment from home. CONCLUSION: BDD-NET is an effective treatment for BDD, and the patients' gains are maintained in the long term. BDD-NET has the potential to increase access to CBT and may lower the threshold for BDD sufferers to seek help in the first place. TRIAL REGISTRATION NUMBER: NCT02010619.