Is Risperidone an Antidepressant?
No, risperidone is not an antidepressant—it is an atypical (second-generation) antipsychotic medication. 1, 2
Classification and Primary Indications
Risperidone is classified as an atypical antipsychotic with a distinct mechanism of action involving potent antagonism of serotonin 5-HT2A, dopamine D2, and alpha-adrenergic receptors. 2, 3 This receptor-binding profile differentiates it from typical antipsychotics and is believed to be related to its therapeutic effects on mood symptoms in specific psychiatric conditions. 2
FDA-Approved Bipolar Disorder Indications
For patients with bipolar disorder specifically, risperidone has two FDA-approved indications:
- Monotherapy for short-term treatment of acute manic or mixed episodes associated with bipolar I disorder 2, 4
- Combination therapy with lithium or valproate for short-term treatment of acute manic or mixed episodes associated with bipolar I disorder 2, 4
The American Academy of Child and Adolescent Psychiatry recommends that when used as adjunctive therapy with mood stabilizers in schizoaffective disorder and bipolar disorder, the mean effective dose is approximately 4.7 mg/day. 5
Limited Role in Depression
While risperidone is not classified as an antidepressant, there is emerging evidence for its use as augmentation therapy in treatment-resistant major depressive disorder:
- Clinical trials demonstrate that low-dose risperidone (0.25-2 mg/day) may improve response and remission rates when added to antidepressants in patients who fail monotherapy 6
- However, this is considered an off-label use and should only be attempted after adequate trials of first-line antidepressants from different classes have failed 6
- The antidepressant properties observed are attributed to its activity at various serotonergic and dopaminergic receptors, not because it functions as a traditional antidepressant 6
Critical Distinction for Bipolar Patients
For bipolar disorder patients, risperidone treats the manic/mixed episodes, not depressive episodes. 2, 4 Its role is fundamentally different from antidepressants:
- Risperidone is effective for acute mania as monotherapy or combined with mood stabilizers 3
- It improves Young Mania Rating Scale (YMRS) scores and global functioning over 3 weeks 3
- Long-term data suggest utility in maintenance treatment of bipolar disorder 4
Important Monitoring Considerations
When prescribing risperidone, particularly in adolescents with bipolar disorder:
- Baseline and periodic liver function monitoring is prudent, as liver enzyme abnormalities have been reported in adolescent males 5
- Monitor for weight gain, which is the most common significant problem with atypical antipsychotics 7
- Risperidone has the highest risk among atypical agents for extrapyramidal side effects 7
- Baseline renal and liver function tests are indicated prior to initiating treatment 5
Bottom line: Risperidone is an antipsychotic used to treat mania in bipolar disorder, not an antidepressant used to treat depression.