Factors associated with prospective long-term treatment adherence among individuals with bipolar disorder.

Objective: Clinical characteristics, adverse effects of medication, and treatment attitudes have been associated with adherence in bipolar populations in cross-sectional studies. The aim of this secondary analysis from a larger study was to identify the association between baseline variables and average treatment adherence over a subsequent three-year period.

Methods: Veterans with bipolar disorder were evaluated on self-reported adherence status at baseline and every six months over a three-year period. The sample was dichotomized into two clinically relevant categories: those who were primarily adherent and those who were primarily nonadherent. Demographic and clinical variables were examined for the two groups of patients in relation to their average adherence over the three-year period.

Results: The study recruited a sample of 306 persons with severe bipolar disorder. The sample was predominantly male (278 men, or 91%), with a mean+/-SD age of 46.6+/-10.1 years. A total of 240 individuals (78%) were largely adherent to treatment, and 37 individuals (12%) were largely nonadherent to treatment. Nonadherent individuals were less likely to be on intensive somatotherapy regimens (p=.001); experienced more barriers to care, including lack of telephone access (p<.05) and life obligations and commitments (p<.05); and had more prior suicide attempts (p=.003).

Conclusions: Nonadherent individuals with bipolar disorder received less intensive pharmacologic treatments, had more suicide attempts, and experienced more barriers to care than adherent individuals. Nonadherence may have system as well as patient components. Consideration of nonadherence as a function of both patient factors and system factors will enhance our ability to understand nonadherence and intervene more effectively.