Medication nonadherence in bipolar disorder: a narrative review

A number of effective maintenance medication options exist for bipolar disorder (BD) and these are regarded as the foundation of long-term treatment in BD. However, nonadherence to medication is common in BD. For example, a large data base study in the United States of America (USA) showed that approximately half of patients with BD were nonadherent with lithium and maintenance medications over a 12 & month period. Such nonadherence carries a high risk of relapse due to the recurrent nature of the illness and the fact that abrupt cessation of treatment, particularly lithium, may cause rebound depression and mania. Indeed, medication nonadherence in BD is associated with significantly increased risks of relapse, recurrence, hospitalization and suicide attempts and a decreased likelihood of achieving remission and recovery, as well as with higher overall treatment costs. Factors associated with nonadherence include adverse effects of medication, complex medication regimens, negative patient attitudes to medication, poor insight, rapid-cycling BD, comorbid substance misuse and a poor therapeutic alliance. Clinicians should routinely enquire about nonadherence in a nonjudgmental fashion. Potential steps to improve adherence include simple pragmatic strategies related to prescribing including shared decision-making, psychoeducation with a clear focus on adherence, reminders (traditional and digital), potentially using a depot rather than an oral antipsychotic, managing comorbid substance misuse and improving therapeutic alliance. Financial incentives have been shown to improve adherence to depot antipsychotics, but this approach raises ethical issues and its long-term effectiveness is unknown. Often a combination of approaches will be required. The strategies that are adopted need to be patient specific, reflecting that nonadherence has no single cause, and chosen by the patient and clinician working together.