Methods of treating developmental disorders such as Angelman syndrome Fragile X syndrome Fragile X associated tremor/ataxia syndrome (FXTAS) Autistic Spectrum Disorder Autism Aspergers syndrome pervasive developmental disorder Childhood Disintegrative Disorder Rett syndrome Lanau Kleffner Syndrome Prader Willi Syndrome Tardive Dyskinesia and/or Williams Syndrome with gaboxadol or a pharmaceutically acceptable salt thereof are provided. The methods provide therapeutic compositions that may be used to improve one or more symptoms of the developmental disorder.
