Objective: The aim of this study was to investigate the efficacy and safety of mirtazapine in the treatment of excessive masturbation and other inappropriate sexual behaviors (ISB) in individuals with the diagnosis of autistic disorder (AD).
Method: Subjects (n = 10; 2 females, 8 males; age range: 5.2-16.4 years) who suffered from excessive masturbation with or without other ISB were treated with mirtazapine for 8 weeks. Clinical Global Impressions-Severity (CGI-S) and Clinical Global Impressions-Improvement (CGI-I) scales were used for the evaluation of symptoms severity and effectiveness. Mirtazapine was started at 7.5-15 mg/day and titrated up to 15-30 mg/day (mean 21.6 +/- 7.9 mg/day). The data for this study were collected from reviewing medical records of all subjects that suffered from ISB and treated with mirtazapine.
Results: CGI scores at baseline and end point ranged from 5 to 7 (mean 6.22 +/- 0.83) and 2 to 4 (mean 3 +/- 0.7), respectively. A nonparametric t-test showed significant difference in CGI-S scores between baseline and end point assessments (Z = -2.725; p = 0.006, p < 0.01). Five subjects showed very much, 3 showed much, and 1 showed moderate improvement in excessive masturbation on the CGI-I scale. One subject dropped out from clinical follow up. Mirtazapine was generally tolerated well. The most frequently reported side effects were increased appetite, weight gain (n = 3; mean 0.78 +/- 1.20 kg), and sedation.
Conclusions: Mirtazapine could be an effective treatment to ameliorate ISB in a young population with a diagnosis of AD. Well-designed, placebo-controlled studies are needed regarding this topic.