Identifying gene-environment interactions in schizophrenia: contemporary challenges for integrated, large-scale investigations.

Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G × E), however, so far, thorough replication of findings is rare and G × E research still faces several conceptual and methodological challenges. In this article, we aim to review these recent developments and illustrate how integrated, large-scale investigations may overcome contemporary challenges in G × E research, drawing on the example of a large, international, multi-center study into the identification and translational application of G × E in schizophrenia.

The impact of substance use at psychosis onset on First Episode Psychosis course: results from a 1 year follow-up study in Bologna.

Objectives: Substance abuse is a well established risk factor for First-Episode Psychosis (FEP), but its influence on FEP course is less clear. Starting from our baseline observation that substance users were younger than non-users at the psychosis onset, we hypothesized that substance use at baseline could be an independent risk factor for a worse clinical course.

Methods: An incidence cohort of patients with FEP collected in an 8year period (2002-2009) at the Bologna West Community Mental Health Centers (CMHCs) was assessed at baseline and at 12month follow-up.

Current cannabis use and age of psychosis onset: a gender-mediated relationship? Results from an 8-year FEP incidence study in Bologna.

This study examined the relationship between gender, illicit drug use and age of onset of psychosis. We analysed data from an epidemiologically based cohort of 160 subjects with first-episode psychosis from community mental health centers. Cannabis was associated with an earlier onset of psychosis compared to other drugs, especially among women.