Abstract

Background: Psychiatric symptoms are prevalent in patients with Prader-Willi syndrome (PWS), mainly behaviour disorders (temper tantrums and stubbornness) and manipulative behaviour, obsessive-compulsive characteristics in relation with food. True psychosis is evident in young adulthood in approximately 5-10% of patients. 
Aim & Objectives: review of psychotic symptoms in patients with a diagnosis of PWS to purpose of a case.
Methods/Study Design: a PWS case report with psychotic symptoms treated with Aripiprazole.
Results/Findings: PWS patients have an increased risk of psychotic disorder or affective illness with a psychotic component, especially young adult patients and those with the maternal uniparental disomy as opposed to paternal deletion. 
Conclusion: Behavioural and psychiatric problems interfere the most with quality of life in adulthood. These should be detected early and treated appropriately with parental education and psychotropic medication if it was necessary. Serotonin agonists have been the most successful in reducing temper outbursts and improving compulsivity. Psychosis is treated in a standard manner.