NAC has recently been demonstrated to be effective in a double-blind, placebo-controlled trial in adults with trichotillomania (chronic hair pulling). Hairpulling is hypothesized to be closely related to tics because these conditions (1) have similar clinical characteristics -- both groups typically experience urges before engaging in pulling or tics, (2) neuroimaging studies suggest they involve similar brain circuits -- the basal ganglia, (3) the same pharmacological treatments (neuroleptics) may be effective for both conditions and (4) they tend to be inherited together in families. In other trials NAC has evidence of some efficacy in treating diverse psychiatric conditions such as bipolar depression, schizophrenia and cocaine dependence.