Controlled studies of risperidone are limited to the acute treatment of mania (both as monotherapy and add-on therapy to a mood stabilizer), with no controlled evidence for maintenance treatment or other use beyond 3 weeks. Due to the limited remaining patent life of risperidone in most markets, it is not expected that Janssen will conduct further studies or file for additional claims in bipolar disorder beyond current acute indications.

Strengths:

• Effective in the treatment of manic and mixed states, either as monotherapy or add-on therapy to a mood stabilizer.
• Rapid onset of antimanic effect which is independent of antipsychotic effects.
• Broad spectrum – it controls mania in a variety of populations (psychotic/non-psychotic, and manic/mixed) and also reduces associated depressive symptoms.
• Does not cause weight gain or QTc prolongation.
• Superior to haloperidol in terms of rates of EPS.

Weaknesses:

• Never studied in patients with bipolar depression.
• Assoiciated with higher rates of EPS compared with other atypical antipsychotics.