The phenomenology and diagnosis of psychiatric illness in people with Prader–Willi syndrome

Abstract

Psychiatric illness in PWS is predominately affective with atypical features. The prevalence and possibly the severity of illness are greater in those with mUPD. We present a 'two-hit' hypothesis, involving imprinted genes on chromosome 15, for the development of affective psychosis in people with PWS, regardless of genetic subtype.