Lifetime prevalence of depression is estimated to be about 12 to
15 percent (1). Recurrent or chronic depression is common (2)
and is often attributed to insufficient treatment (3). Although
medications offer safe and effective treatment and have
relatively benign side effects, many patients with depression do
not get an adequate trial of treatment (4). In fact, up to 52
percent of patients who take antidepressants do not adhere to
treatment, either by missing doses or by prematurely
discontinuing pharmacologic therapy (5,6). In general,
discontinuation rates are highest during the first month of
treatment, with 35 percent of primary care patients dropping out
and a steady decline thereafter (7). The determinants of
nonadherence among patients with depression have not been
sufficiently examined (8). Most studies have used the Health
Belief Model to predict the likelihood of adherence. This model
suggests that patients initiate or continue medication treatment
on the basis of their individual beliefs, attitude