Factors associated with symptomatic improvement and recovery from major depression in primary care patients

This article describes a post-hoc analysis of clinical and psychosocial factors and beliefs about health associated with treatment outcome in a sample of depressed primary care patients (N=181) randomly assigned to a standardized treatment or physician's usual care (UC). Different factors were found to predict clinical outcomes for treatment modality [UC vs. interpersonal psychotherapy (IPT) or nortriptyline (NT)] and the type of outcome evaluated (i.e., depressive symptoms at 8 months or symptomatic and functional recovery at 8 months). Factors associated with treatment-specific outcomes are also described. Consistent with prior studies, lower depressive symptom severity at 8 months was associated with higher baseline functioning, minimal medical co-morbidity, race, and standardized pharmacologic or psychotherapeutic treatment. Additionally, an interaction between treatment modality and health locus of control indicated that individuals perceiving more self-control of their health and who received a standardized treatment experienced greater depressive symptom reduction at 8 months. Factors associated with symptomatic and functional recovery from the depressive episode were also examined. Patients who received a standardized treatment (IPT or NT) perceived greater control of their health and lacked a lifetime generalized anxiety disorder or panic disorder were more likely to recover by month 8 than those who received usual care. While clinical severity and treatment adequacy play an important role in both symptomatic improvement and full recovery from a depressive episode, other key factors such as health beliefs and non-depressive psychopathology also influence recovery.