Recent pharmacotherapy research in autism spectrum disorders (ASD) has successfully focused on treatment of co-occurring symptoms, including inattention, hyperactivity, and irritability that commonly occur in persons with ASD. Despite over two decades of significant pharmacotherapy research, to date no medication has been shown in controlled trials to enhance the core social deficits of ASD. Based upon findings describing the neurobiology of ASD combined with our preliminary results, we believe the novel drug acamprosate will show evidence of reducing social skills deficits associated with ASD.

Each subject with ASD will receive 10 weeks of blinded treatment with acamprosate or matching placebo. After completion of the double-blind phase, all subjects will have an opportunity to receive acamprosate as part of the study procedures for 16 weeks.

Inclusion Criteria:

• 5-17 year-old outpatients
• Diagnosis of ASD
• General good health (determined by exam, history, and laboratory work up)
• Use of up to two concomitant psychotropic drugs (stable dosing for >60 days) not impacting glutamate or gamma-aminobutyric acid A (GABA) neurotransmission is allowed
• Stable seizure disorder (no seizures in 6 months; on same anti-convulsant dose for >60 days)
• Clinical Global Impression Scale Severity score (CGI-S) of 4 (Moderately III)
• Score of 13 on the Social Withdrawal subscale of the Aberrant Behavior Checklist (ABC-SW) at screen and baseline

Exclusion Criteria:

• Potential subjects with a creatinine clearance < 50 mL/min or evidence of a previous trial of acamprosate will be excluded