Objective: The aim of this paper is to review the prevalence, predictors and methods for improving medication adherence in unipolar and bipolar affective disorders.
Method: Studies were identified through Medline and PsycLit searches of English language publications between 1976 and 2001. This was supplemented by a hand search and the inclusion of selected descriptive articles on good clinical practice.
Results: Estimates of medication non-adherence for unipolar and bipolar disorders range from 10 to 60% (median 40%). This prevalence has not changed significantly with the introduction of new medications. There is evidence that attitudes and beliefs are at least as important as side-effects in predicting adherence. The limited number of empirical studies of how to reduce non-adherence offer encouraging evidence that, if recognized, the problem can be overcome.
Conclusion: Only 1–2% of all publications on the treatment of affective disorders explore factors associated with medication non-adherence. This is disappointing as research and clinical data highlight the importance of extended courses of medication in improving the long-term prognosis of affective disorders.