Social anxiety disorder (SAD) is a common anxiety disorder (ANX) with moderate heritability that often co-occurs with other mental disorders. Until now, sample sizes in genetic analyses of SAD have been limited, so that the genetic basis of SAD and its subphenotypes is still largely unknown. In a large cohort comprising n = 1,194 SAD patients derived from five German cohorts and n = 3,409 controls from the Heinz Nixdorf Recall Study, we computed polygenic risk scores (PRS) at six p-thresholds using PRSice-2 based on large-scale genome-wide association studies for depression, major depressive disorder (MDD), ANX, schizophrenia (SCZ), bipolar disorder (BD), attention-deficit/hyperactivity disorder (ADHD), anorexia nervosa (AN), autism spectrum disorder (ASD), and alcohol dependence (AD). We used general linear models to examine the association between the PRS and SAD status. In SAD subsamples, we investigated whether the PRS are associated with SAD subphenotypes (i.e., SAD severity, current depressive symptoms, comorbid MDD) using correlation analyses and a general linear model. Results were corrected for multiple testing. The SAD status was significantly associated with PRS for depression, MDD, ANX, SCZ, BD, AN, and ASD (pBH-adjusted<0.05), but not with PRS for ADHD and AD. In SAD subsamples, the subphenotype analyses revealed no significant associations after correction for multiple testing (pBH-adjusted>0.05). Our results support that SAD seems to be genetically highly overlapping with other mental disorders, which might underline a common psychopathological factor. No significant association was found with SAD severity, current depressive symptoms or comorbid MDD. A better understanding of the genetic architecture of SAD may help to develop new diagnostic and treatment approaches.
L. Sindermann, Angelina Röhrig, F. David et al.· Translational Psychiatry· 0 citations
Abstract Major Depressive Disorder (MDD) is a highly prevalent, severe mental health condition that constitutes one of the leading causes of disability worldwide. While recent animal studies suggest a causal role of the gut microbiome in the pathophysiology of MDD models, evidence in humans is still unclear due to small sample sizes, inconsistent clinical assessment of MDD diagnosis, and methodological limitations regarding causal inference in cross-sectional data. Here, we explicitly address these shortcomings to investigate the potential causal link between the gut microbiome and MDD: First, we replicate previously reported microbiome-depression associations using one of the largest multicenter MDD cohorts for which microbiome data and in-depth diagnostic assessment are available (N = 1,269 MDD patients and controls). We find a significant difference between healthy controls and MDD patients for the relative abundance of four taxa: Eggerthella, Hungatella, Coprobacillus, and Lachnospiraceae FCS020. Second, we employ state-of-the-art, fully data-driven causal inference tools within Judea Pearl's framework, allowing us to derive model constraints from the data rather than relying on potentially strong, unrealistic assumptions. Using this approach, we found evidence for Eggerthella and Hungatella as potential causal contributors to MDD. Furthermore, we show that the potential causal effects of Eggerthella and Hungatella on MDD persist beyond the influence of body mass index, revealing two distinct potential causal pathways linking the gut microbiome to MDD. Finally, the difference in relative abundance of these taxa between healthy and MDD patients was independent of antidepressant medication. Our study provides the first data-driven evidence for a potential causal role of gut microbiota in the pathophysiology of depression in humans.
Leon Fehse, A. H. Ribeiro, N. Winter et al.· Gut microbes· 0 citations