Psychotic symptoms in the general population - an evolutionary perspective.

Our ideas about the intrinsically pathological nature of hallucinations and delusions are being challenged by findings from epidemiology, neuroimaging and clinical research. Population-based studies using both self-report and interview surveys show that the prevalence of psychotic symptoms is far greater than had been previously considered, prompting us to re-evaluate these psychotic symptoms and their meaning in an evolutionary context. This non-clinical phenotype may hold the key to understanding the persistence of psychosis in the population. From a neuroscientific point of view, detailed investigation of the non-clinical psychosis phenotype should provide novel leads for research into the aetiology, nosology and treatment of psychosis.