Lower Bipolar Disorder Rehospitalization Rate With Atypical Antipsychotics

Patients with bipolar I disorder had a lower risk for rehospitalization if they received a prescription for a mood stabilizer and an atypical antipsychotic after discharge from a first lifetime hospitalization as a result of a manic episode, according to a recent study. In contrast, patients who received only a mood stabilizer or a mood stabilizer with a typical antipsychotic had a higher risk for and shorter time to rehospitalization, the researchers found.

Eldar Hochman, MD, PhD, from Geha Mental Health Center in Petach-Tikva, Israel, and colleagues compared rehospitalization rates during 1 year of follow-up for 201 manic patients diagnosed with bipolar I disorder. All had been hospitalized the first time during a manic episode between 2005 and 2013 and were discharged with a mood stabilizer (lithium or valproate) alone (70 patients), a mood stabilizer along with an atypical antipsychotic (63 patients), or a mood stabilizer with a typical antipsychotic (68 patients).

The groups had similar mean daily dose and serum levels of lithium and valproate at discharge. Of all the patients, 35 (17.4%) were rehospitalized for any type of mood episode within a year of discharge: 80% for manic episodes, 2.8% for a mixed episode, and 17.2% for depressive episodes.

Those with the lowest rate of rehospitalization, 6.3%, were the patients discharged with a mood stabilizer and an atypical antipsychotic. The mood stabilizer monotherapy group had a rehospitalization rate of 24.3%, and the group prescribed a mood stabilizer and a typical antipsychotic had a rate of 20.6%. The rehospitalization rate specifically for a manic or mixed episode was also lowest in the mood stabilizer with atypical antipsychotics group, at 4.8%, compared with 21.4% in the monotherapy group and 16.2% in the group who also received typical antipsychotics.

The patients prescribed a mood stabilizer and atypical antipsychotic also had the longest average time to rehospitalization, at 345.5 days. Average time to rehospitalization was 315.1 days for the monotherapy group and 334.1 days for the mood stabilizer with typical antipsychotic group. Similarly, time to rehospitalization for a manic or mixed episode was 349.9 days for the group receiving mood stabilizers and atypical antipsychotics, 321.5 days for the monotherapy group and 343.1 days for the group receiving mood stabilizers with typical antipsychotics.

The researchers conducted an additional analysis that took into account the following sociodemographic and clinical factors (or else the items were already similar among all 3 groups):

• age at first lifetime hospitalization
• age at index hospitalization
• sex
• marital status
• occupational status
• country of birth
• type of mood episode leading to each hospitalization
• length of index hospitalization
• type of index hospitalization (voluntary and involuntary)
• presence of psychotic features during the mood episode
• history of suicide attempt
• psychiatric comorbidities
• type and dosage of psychotropic medications at discharge from the index hospitalization
• serum lithium concentration (mmol/L)
• serum valproate concentration (μg/mL)
• number of previous hospitalizations resulting from major mood episodes and physical comorbidities

In the analysis that accounted for all these factors, mood stabilizers with atypical antipsychotics were still associated with better outcomes than monotherapy, but the improvement over mood stabilizers with typical antipsychotics no longer reached statistical significance.

The researchers acknowledged that limiting the primary outcome to 1-year rehospitalization rates “does not include symptomatic or syndromal recurrences that do not lead to hospitalization and may mask an increase in depressive episode recurrence rates.”

Reference

E. Hochman, A. Krivoy, A. Schaffer, et al. Antipsychotic adjunctive therapy to mood stabilizers and 1-year rehospitalization rates in bipolar disorder: a cohort study. Bipolar Disorders 2016;18:684-691.

doi: 10.1111/bdi.12459