Long-term effects of a collaborative care intervention in persistently depressed primary care patients

J Gen Intern Med. 2002 Oct;17(10):741-8. doi: 10.1046/j.1525-1497.2002.11051.x.


Objective: A previous study described the effect of a collaborative care intervention on improving adherence to antidepressant medications and depressive and functional outcomes of patients with persistent depressive symptoms 8 weeks after the primary care physician initiated treatment. This paper examined the 28-month effect of this intervention on adherence, depressive symptoms, functioning, and health care costs.

Design: Randomized trial of stepped collaborative care intervention versus usual care.

Setting: HMO in Seattle, Wash.

Patients: Patients with major depression were stratified into severe and moderate depression groups prior to randomization.

Interventions: A multifaceted intervention targeting patient, physician, and process of care, using collaborative management by a psychiatrist and a primary care physician.

Measures and main results: The collaborative care intervention was associated with continued improvement in depressive symptoms at 28 months in patients in the moderate-severity group (F1,87 = 8.65; P =.004), but not in patients in the high-severity group (F1,51 = 0.02; P =.88) Improvements in the intervention group in antidepressant adherence were found to occur for the first 6 months (chi2(1) = 8.23; P <.01) and second 6-month period (chi2(1) = 5.98; P <.05) after randomization in the high-severity group and for 6 months after randomization in the moderate-severity group(chi2(1) = 6.10; P <.05). There were no significant differences in total ambulatory costs between intervention and control patients over the 28-month period (F1,180 = 0.77; P =.40).

Conclusions: A collaborative care intervention was associated with sustained improvement in depressive outcomes without additional health care costs in approximately two thirds of primary care patients with persistent depressive symptoms.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Antidepressive Agents / therapeutic use
  • Continuity of Patient Care / economics
  • Depressive Disorder / therapy*
  • Disease Management
  • Female
  • Health Care Costs
  • Health Maintenance Organizations
  • Humans
  • Male
  • Middle Aged
  • Patient Compliance
  • Primary Health Care*
  • Time Factors
  • Treatment Outcome


  • Antidepressive Agents