The current project is an initial step aimed at uncovering genetic aetiology of psychotic experiences in a population based study of adolescents. The aims of the current study are three-fold. First, to examine potential associations between previously identified and reviewed Schizophrenia associating single nucleotide polymorphisms (SNPs) and dimension-specific psychotic experiences in a community based sample, using Twin Early Development Study (TEDS;Oliver & Plomin, 2006) data. Psychotic experiences are measured in TEDS using a quantitative dimension-specific Psychotic Experiences Questionnaire. Second, to create a gene score made up of previously identified risk alleles and to test for associations with psychotic experiences. Third, to replicate significant associations found in stage one of the analyses using Avon Longitudinal Study of Parents and Children (ALSPAC) sample.

It is hypothesised that some of the previously identified Schizophrenia associating SNPs will be also associating with the dimension-specific psychotic experiences. It is further expected that there will be an association between the polygenic scores and psychotic experiences. Finally, it is hypothesised that any statistically significant findings made using TEDS sample will be then replicated using ALSPAC.

The study will employ allelic and genotypic association analysis between SNPs of interest and psychotic-like symptoms as well as polygenic risk analysis. Sex, age and SES will be treated as potential covariates.