Oxytocin treatment for Prader Willi Syndrome

INTERVENTION: In a double blind, randomised, controlled cross‐over trial, young people with Prader Willi Syndrome will be randomly assigned to receive either an eight week course of oxytocin (Syntocinon) or placebo nasal spray, which will be followed by a two week wash out period. After the wash out period, participants will then receive the alternate version of the nasal spray, which will be administered for a further eight week period. The order of first nasal spray administration (either oxytocin or placebo first) will be randomised across participants according to codes held by the compounding chemist. Participants 16 years and over will receive a dose of 40International Units and participants under 16 years will receive a dose of 32 International Units. CONDITION: Prader Willi Syndrome PRIMARY OUTCOME: Eating behaviours (hyperphagia and pica) as measured by the Developmental Behaviour Checklist ‐ Monitoring Chart (DBC‐M) Rages/tantrums as measured by the Developmental Behaviour Checklist ‐ Monitoring Chart (DBC‐M) Weight SECONDARY OUTCOME: Overall behaviour and emotional problems as measured by the Developmental Behaviour Checklist ‐ Parent/Carer version (DBC‐P) for participants 18 years and younger, or Developmental Behaviour Checklist ‐ Adult version (DBC‐A)for participants over 18years, and the Developmental Behaviour Checklist ‐ Teacher version (DBC‐T), Yale‐Brown Obsessive Compulsive Scale (Y‐BOCS) Social cognition as measured by the Reading the Eyes in the Mind Test (RMET) Somnolence as measured by the Epworth Sleepiness Scale (ESS). The Hyperphagia Questionnaire The Movie Stills Task The Wechsler Abbreviated Scale of Intelligence WASI. INCLUSION CRITERIA: Genetically proven diagnosis of Prader Willi Syndrome Mental age above 10 years