Fluoxetine for the treatment of repetitive behaviours in children and adolescents with autism: A randomised double-blind placebo-controlled trial.

Over the last decade, the ‘off label’ use of fluoxetine and other selective serotonin reuptake inhibitor (SSRIs) in children with autism has become increasing common, both in Australia and overseas. However based on the current available literature, the efficacy of SSRIs for the treatment of repetitive behaviours and other symptom domains in autism, is yet to be established. It is therefore of importance that high quality, controlled, and reproducible studies are performed to address the efficacy and safety of SSRIs in children with autism. The aim of this project is to determine the efficacy and safety of Fluoxetine for the treatment of restricted, repetitive and stereotyped behaviours in children and adolescents with autism. Participants will be aged between 7.5 and 18 years, have a known diagnosis of an autism spectrum disorder, and have troublesome restricted, repetitive and stereotyped behaviours causing functional impairment (as defined by the DSM-IV criteria for Autistic Disorder). The study will be a randomised double-blind placebo-controlled trial, with parallel group design. 146 subjects will be randomised into two groups (active and placebo). The duration of participation will be 22 weeks, 16 weeks of study medication. Prior to commencement of the trial, a medical history and physical examination will be performed. Four questionnaires will also be administered: Repetitive Behaviour Scale - Revised, Yale-Brown Obsessive Compulsive Scale, Spence Children’s Anxiety Scale, and the Clinical Global Impression Scale. A neuropsychological battery of tests will also be performed. The study medication will be commenced at 4mg or 8mg/day depending on body weight < or > 40 kg). Following this, further weekly increments will be made if side effects do not emerge, until an effective dose is reached. The maximum dose utilised will be 20mg or 30mg/day by week 4. The effective dose will then be maintained between weeks 5 and 16 of the trial. Repeat assessments will be performed in week 16. This testing will include the previously administered questionnaires. Participants will then be weaned off the study medication between weeks 17 and 20. The active and placebo groups will be compared using independent sample t-tests.