Pharmacotherapy for trichotillomania

Trichotillomania (TTM) (hair-pulling disorder) is a prevalent and disabling disorder characterised by recurrent hair-pulling. The effect of medication on trichotillomania has not been systematically evaluated.

To assess the effects of medication for trichotillomania in adults compared with placebo or other active agents.

We searched the Cochrane Central Register of Controlled Trials and the Cochrane Depression, Anxiety and Neurosis Group Register (to 31 July 2013), which includes relevant randomised controlled trials from the following bibliographic databases: The Cochrane Library (all years); EMBASE (1974 to date); MEDLINE (1950 to date) and PsycINFO (1967 to date). Two review authors identified relevant trials by assessing the abstracts of all possible studies.

We selected randomised controlled trials (RCTs) of a medication versus placebo or active agent for TTM in adults.

Two review authors independently performed the data extraction and 'Risk of bias' assessments, and disagreements were resolved through discussion with a third review author. Primary outcomes included the mean difference (MD) in reduction of trichotillomania symptoms on a continuous measure of trichotillomania symptom severity, and the risk ratio (RR) of the clinical response based on a dichotomous measure, with 95% confidence intervals (CIs).

We identified eight studies with a total of 204 participants and a mean sample size of 25. All trials were single-centre trials, and participants seen on an outpatient basis. Seven studies compared medication and placebo (n = 184); one study compared medication and another active agent (n = 13). Duration of the studies was six to twelve weeks. Meta-analysis was not undertaken because of the methodological heterogeneity of the trials. The studies did not employ intention-to-treat analyses and were at a high risk of attrition bias. Adverse events were not well-documented in the studies.None of the three studies of selective serotonin reuptake inhibitors (SSRIs) demonstrated strong evidence of a treatment effect on any of the outcomes of interest. The unpublished naltrexone study did not provide strong evidence of a treatment effect. Two studies, an olanzapine study and a N-acetylcysteine (NAC) study, reported statistically significant treatment effects. One study of clomipramine demonstrated a treatment effect on two out of three measures of response to treatment.

No particular medication class definitively demonstrates efficacy in the treatment of trichotillomania. Preliminary evidence suggests treatment effects of clomipramine, NAC and olanzapine based on three individual trials, albeit with very small sample sizes.