Alex O. Rothbaum

Psychiatric conditions share common genes, but mechanisms that differentiate diagnoses remain unclear. We present a multidimensional framework for functional analysis of rare copy number variants (CNVs) across 6 diagnostic categories, including schizophrenia (SCZ), autism (ASD), bipolar disorder (BD), depression (MDD), PTSD, and ADHD (N = 574,965). Using gene-set burden analysis (GSBA), we tested duplication (DUP) and deletion (DEL) burden across 2,645 functional gene sets defined by the intersections of pathways, cell types, and cortical regions. While diagnoses converge on shared pathways, mixed-effects modeling revealed divergence of pathway effects by cell type, brain region, and gene dosage. Factor analysis identified latent dimensions aligned with clinical axes. A primary factor (F1) captured reciprocal dose-dependent effects of DUP and DEL in SCZ reflecting positive and negative effects in excitatory versus inhibitory neurons and association versus sensory cortex. SCZ and ASD were both strongly aligned with F1 but with opposing directionalities. Orthogonal factors highlighted neuronal versus non-neuronal effects in mood disorders (F2) and differential spatial distributions of DEL effects in ADHD and MDD (F3). High-impact CNVs at 16p11.2 and 22q11.2 were enriched for combinations of cell-type-specific genes involved in pathways consistent with our broader findings. These results reveal molecular and cellular mechanisms that are broadly shared across psychiatric traits but differ between diagnostic categories in context and directionality.

Background Many reports have documented the relationship between previous traumatic experiences, including childhood trauma, and the development of later life psychopathology, including posttraumatic stress disorder (PTSD). Identification of individuals at greatest risk for the development of PTSD could lead to preventative interventions. The present study examined the developmental course of PTSD after trauma exposure, using histories of previous traumatic experiences and the severity of the reaction to the trauma as predictors. Methods Participants (N = 713) were recruited from Emergency Departments in Miami and Atlanta immediately following a traumatic experience. Histories of previous traumatic experiences and the immediate reaction to the new trauma were examined at baseline. Follow‐up assessments of PTSD severity were conducted at 1, 3, and 6 months. Results Histories of child abuse and pre‐existing trauma symptoms predicted the immediate response to stress (R ² = .21, p < .001) and the initial trauma reaction (p < .005).) A mixed‐model repeated‐measures analysis of variance found that immediate stress response and a history of prior trauma (p < .001) significantly predicted the course of PTSD symptoms. Area under the curve (AUC) analyses suggested that the presence of PTSD at each successive assessment was predicted most substantially by the severity of PTSD at the immediately prior follow‐up assessment (AUC > 0.86). Conclusions The current findings suggest that previous traumatic experiences lead to a greater immediate reaction to trauma and combine to predict the development of PTSD, the maintenance of which is not moderated by these earlier experiences. The identification of people likely to develop PTSD may be aided by the assessment of prior experiences and immediate reactions.