Polygenic and Polyenvironment Interplay in Schizophrenia-Spectrum Disorder and Affective Psychosis; the EUGEI First Episode Study.

Background: Multiple genetic and environmental risk factors play a role in the development of both schizophrenia-spectrum disorders and affective psychoses. How they act in combination is yet to be clarified.

Methods: We analyzed 573 first episode psychosis cases and 1005 controls, of European ancestry.

The impact of schizophrenia genetic load and heavy cannabis use on the risk of psychotic disorder in the EU-GEI case-control and UK Biobank studies.

Background: The association between cannabis and psychosis is established, but the role of underlying genetics is unclear. We used data from the EU-GEI case-control study and UK Biobank to examine the independent and combined effect of heavy cannabis use and schizophrenia polygenic risk score (PRS) on risk for psychosis.

Methods: Genome-wide association study summary statistics from the Psychiatric Genomics Consortium and the Genomic Psychiatry Cohort were used to calculate schizophrenia and cannabis use disorder (CUD) PRS for 1098 participants from the EU-GEI study and 143600 from the UK Biobank.

Cannabis use and cognitive biases in people with first-episode psychosis and their siblings.

Background: Cannabis use and familial vulnerability to psychosis have been associated with social cognition deficits. This study examined the potential relationship between cannabis use and cognitive biases underlying social cognition and functioning in patients with first episode psychosis (FEP), their siblings, and controls.

Methods: We analyzed a sample of 543 participants with FEP, 203 siblings, and 1168 controls from the EU-GEI study using a correlational design.

The effect of polygenic risk score and childhood adversity on transdiagnostic symptom dimensions at first-episode psychosis: evidence for an affective pathway to psychosis.

Childhood adversity is associated with various clinical dimensions in psychosis; however, how genetic vulnerability shapes the adversity-associated psychopathological signature is yet to be studied. We studied data of 583 First Episode Psychosis (FEP) cases from the EU-GEI FEP case-control study, including Polygenic risk scores for major depressive disorder (MDD-PRS), bipolar disorder (BD-PRS) and schizophrenia (SZ-PRS); childhood adversity measured with the total score of the Childhood Trauma Questionnaire (CTQ); and positive, negative, depressive and manic psychopathological domains from a factor model of transdiagnostic dimensions. Genes and environment interactions were explored as a departure from a multiplicative effect of PRSs and total CTQ on each dimension.