Genome-wide association study meta-analysis of 9,619 cases with tic disorders.

BACKGROUND: Despite the significant personal and societal burden of tic disorders (TD), treatment outcomes remain modest, necessitating a deeper understanding of their etiology. Family history is the biggest known risk factor and identifying risk genes could accelerate progress in the field. METHODS: Expanding upon previous sample size limitations, we added 4,800 new TD cases and 971,560 controls, conducting a GWAS meta-analysis with 9,619 cases and 981,048 controls of European ancestry. We attempted to replicate the results in an independent deCODE Genetics GWAS (885 TD cases and 310,367 controls). To characterize GWAS findings, we conducted several post-GWAS gene-based and enrichment analyses. RESULTS: A genome-wide significant hit (rs79244681, p=2.27x10-08) within MCHR2-AS1 was identified, though it was not replicated. Post-GWAS analyses revealed a 13.8% SNP-heritability and three significant genes: BCL11B, NDFIP2, and RBM26. Common variant risk for TD was enriched within genes preferentially expressed in the cortico-striato-thalamo-cortical circuit (including the putamen, caudate, nucleus accumbens, and Brodman area 9) and five brain cell types (excitatory and inhibitory telencephalon-, inhibitory- di- and mesencephalon, hindbrain-, and medium spiny neurons). TD polygenic risk was enriched within loss-of-function intolerant genes (p=0.0017) and high-confidence neurodevelopmental disorder genes (p=0.0108). Of 112 genetic correlations, 43 were statistically significant, showing high positive correlations with most psychiatric disorders. Of the two SNPs previously associated with TD, one (rs2453763) replicated in an independent sub-sample of our GWAS (p=0.00018). CONCLUSIONS: This GWAS was still underpowered to identify high-confidence, replicable loci, but the results suggest imminent discovery of common genetic variants for TD.

Genome-wide association study identifies 30 obsessive-compulsive disorder associated loci.

Obsessive-compulsive disorder (OCD) affects ~1% of the population and exhibits a high SNP-heritability, yet previous genome-wide association studies (GWAS) have provided limited information on the genetic etiology and underlying biological mechanisms of the disorder. We conducted a GWAS meta-analysis combining 53,660 OCD cases and 2,044,417 controls from 28 European-ancestry cohorts revealing 30 independent genome-wide significant SNPs and a SNP-based heritability of 6.7%. Separate GWAS for clinical, biobank, comorbid, and self-report sub-groups found no evidence of sample ascertainment impacting our results. Functional and positional QTL gene-based approaches identified 249 significant candidate risk genes for OCD, of which 25 were identified as putatively causal, highlighting WDR6, DALRD3, CTNND1 and genes in the MHC region. Tissue and single-cell enrichment analyses highlighted hippocampal and cortical excitatory neurons, along with D1- and D2-type dopamine receptor-containing medium spiny neurons, as playing a role in OCD risk. OCD displayed significant genetic correlations with 65 out of 112 examined phenotypes. Notably, it showed positive genetic correlations with all included psychiatric phenotypes, in particular anxiety, depression, anorexia nervosa, and Tourette syndrome, and negative correlations with a subset of the included autoimmune disorders, educational attainment, and body mass index.. This study marks a significant step toward unraveling its genetic landscape and advances understanding of OCD genetics, providing a foundation for future interventions to address this debilitating disorder.

Genome-wide association study identifies new loci associated with OCD.

To date, four genome-wide association studies (GWAS) of obsessive-compulsive disorder (OCD) have been published, reporting a high single-nucleotide polymorphism (SNP)-heritability of 28% but finding only one significant SNP. A substantial increase in sample size will likely lead to further identification of SNPs, genes, and biological pathways mediating the susceptibility to OCD. We conducted a GWAS meta-analysis with a 2-3-fold increase in case sample size (OCD cases: N = 37,015, controls: N = 948,616) compared to the last OCD GWAS, including six previously published cohorts (OCGAS, IOCDF-GC, IOCDF-GC-trio, NORDiC-nor, NORDiC-swe, and iPSYCH) and unpublished self-report data from 23andMe Inc. We explored the genetic architecture of OCD by conducting gene-based tests, tissue and celltype enrichment analyses, and estimating heritability and genetic correlations with 74 phenotypes. To examine a potential heterogeneity in our data, we conducted multivariable GWASs with MTAG. We found support for 15 independent genome-wide significant loci (14 new) and 79 protein-coding genes. Tissue enrichment analyses implicate multiple cortical regions, the amygdala, and hypothalamus, while cell type analyses yielded 12 cell types linked to OCD (all neurons). The SNP-based heritability of OCD was estimated to be 0.08. Using MTAG we found evidence for specific genetic underpinnings characteristic of different cohort-ascertainment and identified additional significant SNPs. OCD was genetically correlated with 40 disorders or traits-positively with all psychiatric disorders and negatively with BMI, age at first birth and multiple autoimmune diseases. The GWAS meta-analysis identified several biologically informative genes as important contributors to the aetiology of OCD. Overall, we have begun laying the groundwork through which the biology of OCD will be understood and described.

A Burden of Rare Copy Number Variants in Obsessive-Compulsive Disorder.

Current genetic research on obsessive-compulsive disorder (OCD) supports contributions to risk specifically from common single nucleotide variants (SNVs), along with rare coding SNVs and small insertion-deletions (indels). The contribution to OCD risk from large, rare copy number variants (CNVs), however, has not been formally assessed at a similar scale. Here we describe an analysis of rare CNVs called from genotype array data in 2,248 deeply phenotyped OCD cases and 3,608 unaffected controls from Sweden and Norway. We found that in general cases carry an elevated burden of large (>30kb, at least 15 probes) CNVs (OR=1.12, P=1.77×10-3). The excess rate of these CNVs in cases versus controls was around 0.07 (95% CI 0.02-0.11, P=2.58×10-3). This signal was largely driven by CNVs overlapping protein-coding regions (OR=1.19, P=3.08×10-4), particularly deletions impacting loss-of-function intolerant genes (pLI>0.995, OR=4.12, P=2.54×10-5). We did not identify any specific locus where CNV burden was associated with OCD case status at genome-wide significance, but we noted non-random recurrence of CNV deletions in cases (permutation P = 2.60×10-3). In cases where sufficient clinical data were available (n=1612) we found that carriers of neurodevelopmental duplications were more likely to have comorbid autism (P<0.001), and that carriers of deletions overlapping neurodevelopmental genes had lower treatment response (P=0.02). The results demonstrate a contribution of large, rare CNVs to OCD risk, and suggest that studies of rare coding variation in OCD would have increased power to identify risk genes if this class of variation were incorporated into formal tests.

Swedish multimodal cohort of patients with anxiety or depression treated with internet-delivered psychotherapy (MULTI-PSYCH).

PURPOSE: Depression and anxiety afflict millions worldwide causing considerable disability. MULTI-PSYCH is a longitudinal cohort of genotyped and phenotyped individuals with depression or anxiety disorders who have undergone highly structured internet-based cognitive-behaviour therapy (ICBT). The overarching purpose of MULTI-PSYCH is to improve risk stratification, outcome prediction and secondary preventive interventions. MULTI-PSYCH is a precision medicine initiative that combines clinical, genetic and nationwide register data. PARTICIPANTS: MULTI-PSYCH includes 2668 clinically well-characterised adults with major depressive disorder (MDD) (n=1300), social anxiety disorder (n=640) or panic disorder (n=728) assessed before, during and after 12 weeks of ICBT at the internet psychiatry clinic in Stockholm, Sweden. All patients have been blood sampled and genotyped. Clinical and genetic data have been linked to several Swedish registers containing a wide range of variables from patient birth up to 10 years after the end of ICBT. These variable types include perinatal complications, school grades, psychiatric and somatic comorbidity, dispensed medications, medical interventions and diagnoses, healthcare and social benefits, demographics, income and more. Long-term follow-up data will be collected through 2029. FINDINGS TO DATE: Initial uses of MULTI-PSYCH include the discovery of an association between PRS for autism spectrum disorder and response to ICBT, the development of a machine learning model for baseline prediction of remission status after ICBT in MDD and data contributions to genome wide association studies for ICBT outcome. Other projects have been launched or are in the planning phase. FUTURE PLANS: The MULTI-PSYCH cohort provides a unique infrastructure to study not only predictors or short-term treatment outcomes, but also longer term medical and socioeconomic outcomes in patients treated with ICBT for depression or anxiety. MULTI-PSYCH is well positioned for research collaboration.

Polygenic risk scores of lithium response and treatment resistance in major depressive disorder.

Treatment response and resistance in major depressive disorder (MDD) are suggested to be heritable. Due to significant challenges in defining treatment-related phenotypes, our understanding of their genetic bases is limited. This study aimed to derive a stringent definition of treatment resistance and to investigate the genetic overlap between treatment response and resistance in MDD. Using electronic medical records on the use of antidepressants and electroconvulsive therapy (ECT) from Swedish registers, we derived the phenotype of treatment-resistant depression (TRD) and non-TRD within ~4500 individuals with MDD in three Swedish cohorts. Considering antidepressants and lithium are first-line treatment and augmentation used for MDD, respectively, we generated polygenic risk scores (PRS) of antidepressants and lithium response for individuals with MDD and evaluated their associations with treatment resistance by comparing TRD with non-TRD. Among 1778 ECT-treated MDD cases, nearly all (94%) used antidepressants before their first ECT and the vast majority had at least one (84%) or two (61%) antidepressants of adequate duration, suggesting these MDD cases receiving ECT were resistant to antidepressants. We did not observe a significant difference in the mean PRS of antidepressant response between TRD and non-TRD; however, we found that TRD cases had a significantly higher PRS of lithium response compared to non-TRD cases (OR = 1.10-1.12 under various definitions). The results support the evidence of heritable components in treatment-related phenotypes and highlight the overall genetic profile of lithium-sensitivity in TRD. This finding further provides a genetic explanation for lithium efficacy in treating TRD.

Association of anxiety or depression with risk of recurrent cardiovascular events and death after myocardial infarction: A nationwide registry study.

BACKGROUND: Depression and anxiety are risk factors for patients with myocardial infarction (MI). However, the association of a previous psychiatric diagnosis of anxiety or depression, or only such self-reported symptoms, with cardiovascular outcomes and mortality post-MI has not been previously examined in the same nationwide cohort. METHODS: We linked demographic, socioeconomic and clinical data from four nationwide Swedish registries for patients enrolled in cardiac rehabilitation (CR) after first-time MI (2006-2015, N = 45,096). After multiple imputation, we applied Cox regression to estimate the post-MI outcome risk for patients with a previous psychiatric diagnosis of anxiety/depression (Diagnosis), patients with no formal diagnosis but self-reported symptoms of anxiety/depression (Symptoms), versus patients with neither Diagnosis nor Symptoms (Reference). RESULTS: During one-year follow-up, fully adjusted models showed that patients with Diagnosis had a higher risk (hazard ratio [95%CI]) of all-cause mortality (1.86 [1.36, 2.53]), reinfarction (1.14 [1.06, 1.22]), their composite (1.15 [1.07, 1.23]), and an extended cardiovascular composite (1.19 [1.12, 1.26]), versus Reference, even though 77% reported no symptoms at the time of MI. In patients with Symptoms, estimates were also elevated yet somewhat attenuated compared to Reference. Findings were overall robust across multiple sensitivity analyses. CONCLUSIONS: Both a previous diagnosis, and present self-reported symptoms of anxiety or depression are associated with an increased risk of death and recurrent cardiovascular events in adults with first-time MI. Only screening for present symptoms is inadequate for assessing this excessive risk. Assessment of both psychiatric history and self-reported symptoms seems warranted for these patients.

Investigating genetic overlap between antidepressant and lithium response and treatment resistance in major depressive disorder.

Treatment response and resistance in major depressive disorder (MDD) are suggested to be heritable. Due to significant challenges in defining treatment-related phenotypes, our understanding of their genetic bases is limited. This study aimed to derive a stringent definition of treatment resistance and to investigate genetic overlap between treatment response and resistance in MDD. Using electronic medical records on the use of antidepressants and electroconvulsive therapy (ECT) from Swedish registers, we derived the phenotype of treatment-resistant depression (TRD) within ~ 4 500 individuals with MDD in three Swedish cohorts. Considering antidepressants and lithium are first-line treatment and augmentation used for MDD, respectively, we generated polygenic risk scores of antidepressant and lithium response for individuals with MDD, and evaluated their associations with treatment resistance by comparing TRD with non-TRD. Among 1 778 ECT-treated MDD cases, nearly all (94%) used antidepressants before first ECT, and the vast majority had at least one (84%) or two (61%) antidepressants of adequate duration, suggesting these MDD cases receiving ECT were resistant to antidepressants. We found that TRD cases tend to have lower genetic load of antidepressant response than non-TRD, although the difference was not significant; furthermore, TRD cases had significantly higher genetic load of lithium response (OR = 1.10-1.12 under different definitions). The results support evidence of heritable components in treatment-related phenotypes and highlight the overall genetic profile of lithium-sensitivity in TRD. This finding further provides a genetic explanation for lithium efficacy in treating TRD.

Operational Definitions of Treatment Response and Remission in Obsessive-Compulsive Disorder Capture Meaningful Improvements in Everyday Life.

INTRODUCTION: The operational definitions of treatment response, partial response, and remission in obsessive-compulsive disorder (OCD) are widely used in clinical trials and regular practice. However, the clinimetric sensitivity of these definitions, that is, whether they identify patients that experience meaningful changes in their everyday life, remains unexplored. OBJECTIVE: The objective was to examine the clinimetric sensitivity of the operational definitions of treatment response, partial response, and remission in children and adults with OCD. METHODS: Pre- and post-treatment data from five clinical trials and three cohort studies of children and adults with OCD (n = 1,528; 55.3% children, 61.1% female) were pooled. We compared (1) responders, partial responders, and non-responders and (2) remitters and non-remitters on self-reported OCD symptoms, clinician-rated general functioning, and self-reported quality of life. Remission was also evaluated against post-treatment diagnostic interviews. RESULTS: Responders and remitters experienced large improvements across validators. Responders had greater improvements than partial responders and non-responders on self-reported OCD symptoms (Cohen's d 0.65-1.13), clinician-rated functioning (Cohen's d 0.53-1.03), and self-reported quality of life (Cohen's d 0.63-0.73). Few meaningful differences emerged between partial responders and non-responders. Remitters had better outcomes across most validators than non-remitters. Remission criteria corresponded well with absence of post-treatment diagnosis (sensitivity/specificity: 93%/83%). Using both the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the Clinical Global Impression Scale yielded more conservative results and more robust changes across validators, compared to only using the Y-BOCS. CONCLUSIONS: The current definitions of treatment response and remission capture meaningful improvements in the everyday life of individuals with OCD, whereas the concept of partial response has dubious clinimetric sensitivity.

Predicting remission after internet-delivered psychotherapy in patients with depression using machine learning and multi-modal data.

This study applied supervised machine learning with multi-modal data to predict remission of major depressive disorder (MDD) after psychotherapy. Genotyped adult patients (n = 894, 65.5% women, age 18-75 years) diagnosed with mild-to-moderate MDD and treated with guided Internet-based Cognitive Behaviour Therapy (ICBT) at the Internet Psychiatry Clinic in Stockholm were included (2008-2016). Predictor types were demographic, clinical, process (e.g., time to complete online questionnaires), and genetic (polygenic risk scores). Outcome was remission status post ICBT (cut-off ≤10 on MADRS-S). Data were split into train (60%) and validation (40%) given ICBT start date. Predictor selection employed human expertise followed by recursive feature elimination. Model derivation was internally validated through cross-validation. The final random forest model was externally validated against a (i) null, (ii) logit, (iii) XGBoost, and (iv) blended meta-ensemble model on the hold-out validation set. Feature selection retained 45 predictors representing all four predictor types. With unseen validation data, the final random forest model proved reasonably accurate at classifying post ICBT remission (Accuracy 0.656 [0.604, 0.705], P vs null model = 0.004; AUC 0.687 [0.631, 0.743]), slightly better vs logit (bootstrap D = 1.730, P = 0.084) but not vs XGBoost (D = 0.463, P = 0.643). Transparency analysis showed model usage of all predictor types at both the group and individual patient level. A new, multi-modal classifier for predicting MDD remission status after ICBT treatment in routine psychiatric care was derived and empirically validated. The multi-modal approach to predicting remission may inform tailored treatment, and deserves further investigation to attain clinical usefulness.

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.

The Genetic Architecture of Obsessive-Compulsive Disorder: Contribution of Liability to OCD From Alleles Across the Frequency Spectrum.

OBJECTIVE: Obsessive-compulsive disorder (OCD) is known to be substantially heritable; however, the contribution of genetic variation across the allele frequency spectrum to this heritability remains uncertain. The authors used two new homogeneous cohorts to estimate the heritability of OCD from inherited genetic variation and contrasted the results with those of previous studies. METHODS: The sample consisted of 2,090 Swedish-born individuals diagnosed with OCD and 4,567 control subjects, all genotyped for common genetic variants, specifically >400,000 single-nucleotide polymorphisms (SNPs) with minor allele frequency (MAF) ≥0.01. Using genotypes of these SNPs to estimate distant familial relationships among individuals, the authors estimated the heritability of OCD, both overall and partitioned according to MAF bins. RESULTS: Narrow-sense heritability of OCD was estimated at 29% (SE=4%). The estimate was robust, varying only modestly under different models. Contrary to an earlier study, however, SNPs with MAF between 0.01 and 0.05 accounted for 10% of heritability, and estimated heritability per MAF bin roughly followed expectations based on a simple model for SNP-based heritability. CONCLUSIONS: These results indicate that common inherited risk variation (MAF ≥0.01) accounts for most of the heritable variation in OCD. SNPs with low MAF contribute meaningfully to the heritability of OCD, and the results are consistent with expectation under the "infinitesimal model" (also referred to as the "polygenic model"), where risk is influenced by a large number of loci across the genome and across MAF bins.

Genetics of obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a psychiatric disorder with multiple symptom dimensions (e.g. contamination, symmetry). OCD clusters in families and decades of twin studies clearly demonstrate an important role for genetics in the etiology of the disorder. METHODS: In this review, we summarize the genetic epidemiology and molecular genetic studies of OCD and obsessive-compulsive symptoms. RESULTS: OCD is a heritable, polygenic disorder with contributions from both common and rare variants, including de novo deleterious variations. Multiple studies have provided reliable support for a large additive genetic contribution to liability to OCD, with discrete OCD symptom dimensions having both shared and unique genetic risks. Genome-wide association studies have not produced significant results yet, likely because of small sample sizes, but larger meta-analyses are forthcoming. Both twin and genome-wide studies show that OCD shares genetic risk with its comorbid conditions (e.g. Tourette syndrome and anorexia nervosa). CONCLUSIONS: Despite significant efforts to uncover the genetic basis of OCD, the mechanistic understanding of how genetic and environmental risk factors interact and converge at the molecular level to result in OCD's heterogeneous phenotype is still mostly unknown. Future investigations should increase ancestral genetic diversity, explore age and/or sex differences in genetic risk for OCD and expand the study of pharmacogenetics, gene expression, gene × environment interactions and epigenetic mechanisms for OCD.

Genome-wide association study of patients with a severe major depressive episode treated with electroconvulsive therapy.

Although large genome-wide association studies (GWAS) of major depressive disorder (MDD) have identified many significant loci, the SNP-based heritability remains notably low, which might be due to etiological heterogeneity in existing samples. Here, we test the utility of targeting the severe end of the MDD spectrum through genome-wide SNP genotyping of 2725 cases who received electroconvulsive therapy (ECT) for a major depressive episode (MDE) and 4035 controls. A subset of cases (n = 1796) met a narrow case definition (MDE occurring in the context of MDD). Standard GWAS quality control procedures and imputation were conducted. SNP heritability and genetic correlations with other traits were estimated using linkage disequilibrium score regression. Results were compared with MDD cases of mild-moderate severity receiving internet-based cognitive behavioral therapy (iCBT) and summary results from the Psychiatric Genomics Consortium (PGC). The SNP-based heritability was estimated at 29-34% (SE: 6%) for the narrow case definition, considerably higher than the 6.5-8.0% estimate in the most recent PGC MDD study. Our severe MDE cases had smaller genetic correlations with neurodevelopmental disorders and neuroticism than PGC MDD cases but higher genetic risk scores for bipolar disorder than iCBT MDD cases. One genome-wide significant locus was identified (rs114583506, P = 5e-8) in an intron of HLA-B in the major histocompatibility locus on chr6. These results indicate that individuals receiving ECT for an MDE have higher burden of common variant risk loci than individuals with mild-moderate MDD. Furthermore, severe MDE shows stronger relations with other severe adult-onset psychiatric disorders but weaker relations with personality and stress-related traits than mild-moderate MDD. These findings suggest a different genetic architecture at the severest end of the spectrum, and support further study of the severest MDD cases as an extreme phenotype approach to understand the etiology of MDD.

Nordic OCD & Related Disorders Consortium: Rationale, design, and methods.

Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder, yet its etiology is unknown and treatment outcomes could be improved if biological targets could be identified. Unfortunately, genetic findings for OCD are lagging behind other psychiatric disorders. Thus, there is a pressing need to understand the causal mechanisms implicated in OCD in order to improve clinical outcomes and to reduce morbidity and societal costs. Specifically, there is a need for a large-scale, etiologically informative genetic study integrating genetic and environmental factors that presumably interact to cause the condition. The Nordic countries provide fertile ground for such a study, given their detailed population registers, national healthcare systems and active specialist clinics for OCD. We thus formed the Nordic OCD and Related Disorders Consortium (NORDiC, www.crowleylab.org/nordic), and with the support of NIMH and the Swedish Research Council, have begun to collect a large, richly phenotyped and genotyped sample of OCD cases. Our specific aims are geared toward answering a number of key questions regarding the biology, etiology, and treatment of OCD. This article describes and discusses the rationale, design, and methodology of NORDiC, including details on clinical measures and planned genomic analyses.

A genome-wide association meta-analysis of prognostic outcomes following cognitive behavioural therapy in individuals with anxiety and depressive disorders.

Major depressive disorder and the anxiety disorders are highly prevalent, disabling and moderately heritable. Depression and anxiety are also highly comorbid and have a strong genetic correlation (rg ≈ 1). Cognitive behavioural therapy is a leading evidence-based treatment but has variable outcomes. Currently, there are no strong predictors of outcome. Therapygenetics research aims to identify genetic predictors of prognosis following therapy. We performed genome-wide association meta-analyses of symptoms following cognitive behavioural therapy in adults with anxiety disorders (n = 972), adults with major depressive disorder (n = 832) and children with anxiety disorders (n = 920; meta-analysis n = 2724). We estimated the variance in therapy outcomes that could be explained by common genetic variants (h2SNP) and polygenic scoring was used to examine genetic associations between therapy outcomes and psychopathology, personality and learning. No single nucleotide polymorphisms were strongly associated with treatment outcomes. No significant estimate of h2SNP could be obtained, suggesting the heritability of therapy outcome is smaller than our analysis was powered to detect. Polygenic scoring failed to detect genetic overlap between therapy outcome and psychopathology, personality or learning. This study is the largest therapygenetics study to date. Results are consistent with previous, similarly powered genome-wide association studies of complex traits.

Genetics of response to cognitive behavior therapy in adults with major depression: a preliminary report.

Major depressive disorder is heritable and a leading cause of disability. Cognitive behavior therapy is an effective treatment for major depression. By quantifying genetic risk scores based on common genetic variants, the aim of this report was to explore the utility of psychiatric and cognitive trait genetic risk scores, for predicting the response of 894 adults with major depressive disorder to cognitive behavior therapy. The participants were recruited in a psychiatric setting, and the primary outcome score was measured using the Montgomery Åsberg Depression Rating Scale-Self Rated. Single-nucleotide polymorphism genotyping arrays were used to calculate the genomic risk scores based on large genetic studies of six phenotypes: major depressive disorder, bipolar disorder, attention-deficit/hyperactivity disorder, autism spectrum disorder, intelligence, and educational attainment. Linear mixed-effect models were used to test the relationships between the six genetic risk scores and cognitive behavior therapy outcome. Our analyses yielded one significant interaction effect (B = 0.09, p < 0.001): the autism spectrum disorder genetic risk score correlated with Montgomery Åsberg Depression Rating Scale-Self Rated changes during treatment, and the higher the autism spectrum disorder genetic load, the less the depressive symptoms decreased over time. The genetic risk scores for the other psychiatric and cognitive traits were not related to depressive symptom severity or change over time. Our preliminary results indicated, as expected, that the genomics of the response of patients with major depression to cognitive behavior therapy were complex and that future efforts should aim to maximize sample size and limit subject heterogeneity in order to gain a better understanding of the use of genetic risk factors to predict treatment outcome.

Internet-Based Extinction Therapy for Worry: A Randomized Controlled Trial.

Worry is a common phenotype in both psychiatric patients and the normal population. Worry can be seen as a covert behavior with primary function to avoid aversive emotional experiences. Our research group has developed a treatment protocol based on an operant model of worry, where we use exposure-based strategies to extinguish the catastrophic worry thoughts. The aim of this study was to test this treatment delivered via the Internet in a large-scale randomized controlled trial. We randomized 140 high-worriers (defined as > 56 on the Penn State Worry Questionnaire [PSWQ]) to either Internet-based extinction therapy (IbET) or to a waiting-list condition (WL). Results showed that IbET was superior to WL with an overall large between-group effect size of d = 1.39 (95% confidence interval [1.04,1.73]) on the PSWQ. In the IbET group, 58% were classified as responders. The corresponding figure for WL participants was 7%. IbET was also superior to the WL on secondary outcome measures of anxiety, depression, meta-cognitions, cognitive avoidance, and quality of life. Overall treatment results were maintained for the IbET group at 4- and 12-month follow-up. The results from this trial are encouraging as they indicate that worry can be targeted with an accessible and novel intervention for worry. Replication trials with active control group are needed.