RATIONALE:

There are no drugs that have been shown to effectively treat the core social impairment of autism.

OBJECTIVES:

The purpose of this study was to examine the effectiveness and tolerability of memantine for social impairment in children and adolescents with pervasive developmental disorders (PDDs).

MATERIALS AND METHODS:

Medical records of 18 patients with PDDs consecutively treated with open-label memantine were retrospectively reviewed. The data reviewed included prospectively obtained assessments of severity (S) and improvement (I) using the Clinical Global Impressions Scale (CGI). Pretrial and follow-up parent ratings were also available on six patients using the Aberrant Behavior Checklist (ABC).

RESULTS:

Eighteen patients (15 male, 3 female; mean age=11.4 years, range 6-19 years) received memantine (mean dosage=10.1 mg/day, range 2.5-20 mg/day) over a mean duration of 19.3 weeks (range 1.5-56 weeks). Eleven of 18 (61%) patients were judged responders to memantine based on a rating of "much improved" or "very much improved" on the CGI-I. Significant improvement was also seen on the CGI-S. Improvement was primarily seen clinically in social withdrawal and inattention. Adverse effects occurred in 7 of 18 (39%) patients and led to drug discontinuation in 4 of 18 (22%) patients. Thirteen of 18 (72%) patients received stable doses of concomitant medications during the memantine trial.

CONCLUSIONS:

In this open-label retrospective study, memantine was effective in a number of patients with PDDs. Controlled studies are warranted to further assess the efficacy and safety of memantine in PDDs.