Impact of antidepressant drug adherence on comorbid medication use and resource utilization

Arch Intern Med. 2005 Nov 28;165(21):2497-503. doi: 10.1001/archinte.165.21.2497.


Background: Patients with depression are often nonadherent to therapy for depression and chronic comorbid conditions.

Methods: To determine whether improved antidepressant medication adherence is associated with an increased likelihood of chronic comorbid disease medication adherence and reduced medical costs, we conducted a retrospective study of patients initiating antidepressant drug therapy with evidence of dyslipidemia, coronary artery disease (CAD), or both; diabetes mellitus (DM); or CAD/dyslipidemia and DM identified from a claims database. Measures included antidepressant medication adherence, measured by medication possession ratio during 180 days without a 15-day gap before 90 days of therapy; comorbid medication adherence, measured by medication possession ratio during 1 year; and the association between improved antidepressant drug adherence and disease-specific and total medical costs.

Results: Of 8040 patients meeting the study criteria, those adherent to antidepressant medication were more likely to be adherent to comorbid therapy vs those nonadherent to antidepressant drug therapy (CAD/dyslipidemia: odds ratio [OR], 2.13; DM: OR, 1.82; and CAD/dyslipidemia/DM: OR, 1.45; P<.001 for all). Patients adherent to antidepressant drug therapy also had significantly lower disease-specific charges vs nonadherent patients (17% lower in CAD/dyslipidemia, P = .02; 8% lower in DM, P = .39; and 14% lower in CAD/dyslipidemia/DM, P = .38). These patients also incurred lower total medical charges (6.4% lower in CAD/dyslipidemia, P = .048; 11.8% lower in DM, P = .04; and 19.8% lower in CAD/dyslipidemia/DM, P = .03).

Conclusions: Antidepressant drug adherence was associated with increased comorbid disease medication adherence and reduced total medical costs for CAD/dyslipidemia, DM, and CAD/dyslipidemia/DM. Future studies should investigate the relationship between increased adherence and costs beyond 1 year.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antidepressive Agents / economics
  • Antidepressive Agents / therapeutic use*
  • Coronary Disease / complications*
  • Coronary Disease / economics
  • Depression / complications
  • Depression / drug therapy*
  • Diabetes Mellitus / economics*
  • Drug Utilization Review*
  • Dyslipidemias / complications*
  • Dyslipidemias / economics
  • Female
  • Health Care Costs
  • Humans
  • Male
  • Middle Aged
  • Patient Compliance*
  • Retrospective Studies
  • United States


  • Antidepressive Agents