Trichotillomania is an impulse control disorder. There is growing evidences of the involvement of dopaminergic neurotransmission in the pathophysiology of trichotillomania. Reported increase in the prevalence of ADHD among patients with impulse control disorders, such as pathological gambling as well as trichotillomania, may result from the overlapping pathophisiological background. It is hypothesized that in cases of ADHD comorbid with trichotillomania methtylphenidate treatment will exhibit beneficial effects in both the ADHD and the hair pulling.