Hospital utilization rates following antipsychotic dose reduction in mood disorders: implications for treatment of tardive dyskinesia.

BACKGROUND: The relative benefits and risks of long-term maintenance treatment with antipsychotics have not been well studied in patients with bipolar disorder and major depressive disorder. For example, while antipsychotic dose reduction has been recommended in the management of serious side effects associated with antipsychotics, there is limited evidence on the impact of lowering doses on the course of underlying mood disorders. METHODS: This retrospective cohort study analyzed the impact of antipsychotic dose reduction in patients with bipolar disorder or major depressive disorder. Medical claims from six US states over a 6-year period were analyzed for patients with ≥10% or ≥ 30% reductions in antipsychotic dose (cases) and compared using survival analyses with matched controls receiving a stable dosage. Outcomes included hospitalizations for disease-specific mood disorders, other psychiatric disorders and all-cause emergency room visits, and claims for tardive dyskinesia. RESULTS: A total of 23,992 patients with bipolar disorder and 17,766 with major depressive disorder had a ≥ 10% dose reduction, while 19,308 and 14,728, respectively, had a ≥ 30% dose reduction. In multivariate analyses, cases with a ≥ 10% dose reduction had a significantly increased risk of disease-specific admission (bipolar disorder: hazard ratio [95% confidence interval], 1.22 [1.15-1.31]; major depressive disorder: 1.22 [1.11-1.34]), other psychiatric admission (bipolar disorder: 1.19 [1.13-1.24]; major depressive disorder: 1.17 [1.11-1.23]), all-cause admission (bipolar disorder: 1.17 [1.12-1.23]; major depressive disorder: 1.11 [1.05-1.16]), and all-cause emergency room visits (bipolar disorder: 1.09 [1.05-1.13]; major depressive disorder: 1.07 [1.02-1.11]) (all P <  0.01). Similar results were observed following an ≥30% dose reduction. Dose reduction was not associated with decreased claims for tardive dyskinesia. CONCLUSIONS: Patients with mood disorders who had antipsychotic dose reductions showed small but statistically significant increases in all-cause and mental health-related hospitalizations, which may lead to increased healthcare costs. These results highlight the need for additional long-term studies of the necessity and safety of maintenance antipsychotic treatment in mood disorders.