Methylphenidate treatment in pediatric patients with attention-deficit/hyperactivity disorder and comorbid trichotillomania: a preliminary report.

Objectives: Trichotillomania (TTM) is a heterogenic mental disorder with a high rate of comorbidity and stressful life events (SLEs). Serotonergic and dopaminergic dysfunction are implicated in the pathophysiology of TTM. As in other impulse control disorders, increased prevalence of attention-deficit/hyperactivity disorder (ADHD) is reported in patients with TTM as well. This study aimed to assess the efficacy and tolerability of methylphenidate (MPH) treatment in children and adolescents who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for both ADHD and TTM.

Methods: Nine children and adolescents, aged 6 to 18 years, diagnosed with ADHD and TTM, were treated with MPH for a 12-week period. The severity of ADHD was assessed using the ADHD Rating Scale, and the hair pulling was rated using the Massachusetts General Hospital Hair-Pulling Scale. Additional scales were used for assessing depression and anxiety levels, and history of SLE was recorded.

Results: Significant improvement was detected in ADHD after MPH treatment (P < 0.003), but no significant change was observed in hair pulling, as measured by the Massachusetts General Hospital Hair-Pulling Scale (P = 0.096) or in depression and anxiety levels. Lack of response of TTM to MPH (improvement, <50%) was associated with higher rate of positive SLE history (P = 0.047).

Conclusions: Some efficacy of MPH treatment was shown in TTM patients with low rate of SLE. A large-scale study is mandatory to evaluate the efficacy of MPH for TTM in ADHD/TTM patients.