Prader-Willi syndrome and cycloid psychoses

The psychiatric symptomatology of people with Prader-Willi syndrome (PWS) h as mainly been described in case reports and some large-scale descriptive s tudies. Unfortunately, there is still no systematic description of all the psychiatric symptoms which accompany this chromosomal error. Symptoms of mo od disorder and anxiety dominate the picture of PWS, although some reports also mention psychotic symptoms with variations in prevalence of between 15 % and 60%. The present paper presents Six case reports of adult male subjec ts with a diagnosis of PWS and psychiatric symptoms who fulfill the criteri a for cycloid psychosis (ICD-IO F.23.0). This psychotic disorder requires a specific psychopharmacological approach with mood stabilizing agents, part icularly Lithium. It is concluded that subjects with PWS may be especially vulnerable to the development of cycloid psychosis, which suggests the exis tence of a specific 'psychopathological phenotype'.