T41 - Dissecting Religious Delusions In Schizophrenia: The Interplay Of Religious Activity And Polygenic Burden

Abstract

Background Religious delusions are common symptoms in patients experiencing psychosis. They have been associated with greater severity of illness. However, the prevalence of religious delusions varies considerably between different cultures and societies. To enhance our knowledge of this distinct psychotic feature, we investigated if genetic and/or environmental factors were associated with the occurrence of religious delusions. Methods We studied 271 adult German patients with schizophrenia or schizoaffective disorder diagnosed according to DSM-IV criteria. For 196 of these patients, we were able to calculate PGC- schizophrenia polygenic risk scores (PGC-SZ-PRS). Polygenic risk scores reflect the cumulative burden of risk alleles carried by an individual according to the well-powered genome-wide association study (GWAS) investigated by the Psychiatric Genomics Consortium (PGC). Association of variables with a lifetime occurrence of religious delusions was tested by multiple logistic regression with occurrence of religious delusions being the binary target. The following variables were considered as putative predictors: self-reported degree of religious activity, DSM-IV diagnosis, sex, age, education level, marital status, presence of acute delusion at the time of interview and the PGC-SZ-PRS. Results Of the 271 patients (217 Christian, 9 Muslim, 45 without religious denomination), 102 (38%) experienced religious delusions during illness episodes. Neither declaring a religious denomination nor the self-reported degree of religious activity differed between subjects who were acutely versus not acutely delusional at the time of interview. The risk of experiencing religious delusions was significantly increased in individuals with a strong religious activity compared to subjects without a religious denomination (OR 3.3, p= 0.014). Low or moderate religious activity had no significant effect. None of the other covariates (DSM-diagnosis, sex, age, school education, marital status, acute delusion at the time of interview) were significantly associated with the lifetime occurrence of religious delusions. The same analysis including only 196 subjects for whom SZ-PRS score were available revealed the same effect of high religious activity on occurrence of religious delusions (OR 3.0, p=0.047). In these patients, the risk of experiencing religious delusions was also higher when the PGC-SZ-PRS increased by one sample standard deviation (OR 1.5, p=0.025). Discussion Our results suggest that the occurrence of religious delusions in schizophrenia and schizoaffective disorders is associated with environmental as well as genetic influences. Our data imply that high religious activity and a high SZ-PRS are largely independent liability factors. In conclusion, religious delusions may typically be seen in patients with a high degree of religious activity and/or a high polygenic burden of schizophrenia risk alleles. Moderate religious activity seemed to have no negative effect and may even be helpful for coping with these disorders.