Psychotic-like experiences in the general population: characterizing a high-risk group for psychosis

Abstract

Recent research shows that psychotic symptoms, or psychotic-like experiences (PLEs), are reported not only by psychosis patients but also by healthy members of the general population. Healthy individuals who report these symptoms are considered to represent a non-clinical psychosis phenotype, and have been demonstrated to be at increased risk of schizophrenia-spectrum disorder. Converging research now shows that this non-clinical psychosis phenotype is familial, heritable and covaries with familial schizophrenia-spectrum disorder. A review of the research also shows that the non-clinical phenotype is associated extensively with schizophrenia-related risk factors, including social, environmental, substance use, obstetric, developmental, anatomical, motor, cognitive, linguistic, intellectual and psychopathological risk factors. The criterion and construct validity of the non-clinical psychosis phenotype with schizophrenia demonstrates that it is a valid population in which to study the aetiology of psychosis. Furthermore, it suggests shared genetic variation between the clinical and non-clinical phenotypes. Much remains to be learned about psychosis by broadening the scope of research to include the non-clinical psychosis phenotype.

Predicting Risk and the Emergence of Schizophrenia

“…152 Young people in the general population who report psychotic symptoms have been shown to share a wide range of risk factors with schizophrenia patients, including social, environmental, substance use, obstetric, developmental, anatomic, and intellectual risk factors. 153 For these reasons, this population has been considered to form part of an extended psychosis phenotype, comprised of ostensibly healthy community-based individuals with occasional psychotic symptoms on one end and schizophrenia patients on the other end. Researchers have argued that work on this extended psychosis phenotype may provide valuable insights into the etiology of clinical psychotic disorder.…”

Prevalence of psychotic symptoms in childhood and adolescence: a systematic review and meta-analysis of population-based studies

“…Individuals who report psychotic symptoms have also been demonstrated to share a wide range of risk factors with psychosis patients, including shared obstetric, developmental, substance use, social and environmental risk factors (for review, see Kelleher and Cannon, 2011).…”

Childhood adversity and psychosis: Examining whether the association is due to genetic confounding using a monozygotic twin differences approach

“…A growing body of research indicates that attenuated psychotic experiences are present in a substantial proportion of healthy individuals (1)(2)(3). This evidence supports the conceptualization of psychosis as a continous trait, the distribution of which extends into the general population (4)(5).…”