Risperidone-related reversal of primary enuresis: an unusual case report.

Occasional reports have documented treatment-emergent enuresis with medication regimens that include risperidone. In contrast to these reports, we present a 12-year-old girl with mild mental retardation and primary nocturnal enuresis who received risperidone (0.5 mg/day) for the isolated symptom of inappropriate smiling. Surprisingly, in addition to reduction in inappropriate smiling, risperidone also substantially decreased the frequency of enuresis. These benefits with risperidone were confirmed in an on-off-on treatment sequence. To our knowledge, this is the first case in literature of primary enuresis responding to low-dose risperidone. Low-dose risperidone may merit study in children with enuresis. Clinical implications and possible mechanisms are discussed.