The effects of adherence to antidepressant treatment guidelines on relapseand recurrence of depression

Background: Depression is associated with high rates of relapse and recurre nce during a patient's lifetime. Current guidelines regarding treatment rec ommend 4 to 9 months of continuation antidepressant therapy following remis sion of acute symptoms to allow more complete resolution of the episode. In this article, we test whether adherence to these recommendations reduces t he likelihood of relapse or recurrence in a Medicaid population. Methods: We used a Medicaid database covering 1989 through 1994. The sample consists of the 4052 adult patients who filled an antidepressant prescript ion at the time of an initial diagnosis of depression. These patients were followed up for up to 2 years. Timing and counts of antidepressant prescrip tion claims are used to construct a proxy measure for adherence to guidelin es. Relapse or recurrence is defined by evidence of a new episode requiring antidepressant treatment, hospital admission for depression, electroconvul sive therapy, emergency department visit for mental health, or attempted su icide. We used survival analysis to predict relapse or recurrence for each patient and to examine the effect of following treatment guidelines on rela pse and recurrence. Results: Approximately one fourth of the patients bad a relapse or recurren ce during their follow-up period. Factors that affect relapse and recurrenc e include comorbidities, race, and guideline adherence. Those who continued therapy with their initial antidepressant were least likely to experience relapse or recurrence; those who discontinued their antidepressant early we re most likely to experience relapse or recurrence. Conclusion: Adherence to depression treatment guidelines with an antidepres sant that is likely to have continuous use by patients reduces the probabil ity of relapse or recurrence.