Does Risperidone Consta Reduce Relapse and Rehospitalization in Bipolar Disorder?

Bipolar disorder arguably represents the most difficult to treat of all psychiatric disorders. In fact, long-term stabilization is more the exception than the rule, and the majority of patients experience frequent relapses of illness. Studies have shown that both bipolar I and II patients spend about half of their weeks in a significant symptomatic state. Relapses and persistent illness result in substantial morbidity, mortality, and disability.

Symptomatic recurrences happen as a result of breakthrough symptoms during active treatment and intermittent non-adherence. Therefore, enhanced control of symptoms, coupled with ensured adherence, is very likely to improve the long-term outcome of this difficult-to-treat condition.

Risperidone has been shown to be effective in controlling symptoms of acute mania or mixed state in two registration monotherapy and one combination treatment study with lithium or valproate, as well as several smaller trials. However, longer-term treatment studies are relatively lacking. As well, although Risperdal Consta(TM) has been shown to be of benefit in prevention of relapse in patients with schizophrenia, relatively little longer-term data in bipolar disorder is available. Nonetheless, both risperidone and Risperdal Consta (TM) are likely to be highly efficacious for the maintenance prevention of relapse in bipolar disorder. Moreover, Risperdal Consta(TM) helps to ensure longer-term treatment effectiveness, both by better adherence and improved control of symptoms. The present study is intended to determine whether Risperdal Consta(TM) injections, added to ongoing pharmacotherapy, will improve outcome relative to treatment as usual.

Inclusion criteria

• Be physically healthy
• 18-60 years of age
• Have a DSM-IV diagnosis of bipolar disorder in any phase, but without current psychotic features; with a history of symptomatic relapse on four or more occasions over the last year prior to the initiation of study for the treatment of bipolar disorder (type I or II, manic, hypomanic, mixed, or depressive type), with at least 1 in the previous 6 months.
• Have a screening Hamilton Rating Scale for Depression-17 item (HAM-D17) score of > 8 or a Young Mania Rating Scale (YMRS) > 8.

Exclusion criteria

• Have any medical condition that would preclude treatment with Risperdal Consta(TM)
• Have type 2 diabetes
• Have hyperlipidemia (baseline total cholesterol >280)
• Have any clinically significant unstable medical condition
• Have currently active psychotic symptoms (hallucinations or delusions) or carry a diagnosis of another psychotic disorder (schizophrenia, schizoaffective disorder, delusional disorder)
• Have a documentable history of non-response to Risperidal Consta (TM)
• Have a score of 4 on the suicide item (item 3) of the HAM-D scale and/or a determination by the investigator of significant suicide risk
• Require hospitalization between the screening and baseline visits, or require hospitalization immediately following baseline
• Have a medical contraindication or hypersensitivity to risperidone or Risperdal Consta (TM)