title: What causes the onset of psychosis?
abstract: It has become increasingly clear that the simple neurodevelopmental model fails to explain many aspects of schizophrenia including the timing of the onset, and the nature of the abnormal perceptions. Furthermore, we do not know why some members of the general population have anomalous experiences but remain well, while others enter the prodrome of psychosis, and a minority progress to frank schizophrenia. We suggest that genes or developmental damage result in individuals vulnerable to dopamine deregulation. In contemporary society, this is often compounded by abuse of drugs such as amphetamines and cannabis, which then propel the individual into a state of dopamine-induced misinterpretation of the environment. Certain types of social adversity such as migration and social isolation, as well as affective change can also contribute to this. Thereafter, biased cognitive appraisal processes result in delusional interpretation of the abnormal perceptual experiences. Thus, a plausible model of the onset of psychosis needs to draw not only on neuroscience, but also on the insights of social psychiatry and cognitive psychology.
authors.affiliation: Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK. m.broome@iop.kcl.ac.uk
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Broome
authors.forename: James B
authors.initials: JB
authors.lastname: Woolley
authors.forename: Paul
authors.initials: P
authors.lastname: Tabraham
authors.forename: Louise C
authors.initials: LC
authors.lastname: Johns
authors.forename: Elvira
authors.initials: E
authors.lastname: Bramon
authors.forename: Graham K
authors.initials: GK
authors.lastname: Murray
authors.forename: Carmine
authors.initials: C
authors.lastname: Pariante
authors.forename: Philip K
authors.initials: PK
authors.lastname: McGuire
authors.forename: Robin M
authors.initials: RM
authors.lastname: Murray
mesh_terms: D001921:Brain / Q000503:physiopathology; D003469:Culture; D006801:Humans; D011584:Psychology; D011618:Psychotic Disorders / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D012559:Schizophrenia / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology; D012931:Social Environment; D019966:Substance-Related Disorders / Q000150:complications / Q000453:epidemiology