Treatment adherence with antipsychotic medications in bipolar disorder

OBJECTIVES: Atypical antipsychotic medications are a relatively new, increasingly prominent component of the treatment armamentarium for bipolar disorder. Information on adherence with antipsychotics among individuals with bipolar disorder in general, and atypical antipsychotics in particular, is currently quite limited. Using data from the VA National Psychosis Registry, we examined adherence with antipsychotic medications among patients with bipolar disorder (n = 73,964). METHODS: Antipsychotic medication adherence among veterans with bipolar disorder was evaluated using the medication possession ratio and categorizing patients into three groups: fully adherent, partially adherent and non-adherent. We compared characteristics of bipolar patients who received versus those who did not receive antipsychotic medication, and also identified predictors of poor adherence with antipsychotic medications. RESULTS: Approximately 45% (n = 32,993) of all individuals with bipolar disorder were prescribed antipsychotic medication. Individuals who were prescribed antipsychotic medications were younger and more often had comorbid substance abuse or post-traumatic stress disorder compared to individuals with bipolar disorder who were not prescribed antipsychotic medication. Just over half (51.9%) of individuals appear to be fully adherent with antipsychotic medications, while 48.1% of individuals are either partially adherent or non-adherent with antipsychotic medications. Factors associated with treatment non-adherence were younger age, minority ethnicity, comorbid substance abuse and homelessness. CONCLUSIONS: Treatment non-adherence is a major issue for close to half of individuals with bipolar disorder prescribed antipsychotic medication. Additional studies are needed to better understand treatment adherence within the full range of pharmacologic therapies among individuals with bipolar disorder.