Diabetes in primary care: prospective associations between depression, nonadherence and glycemic control

Psychother Psychosom. 2010;79(3):172-8. doi: 10.1159/000296135. Epub 2010 Mar 17.


Background: Findings are inconsistent regarding the degree to which depression may exert a negative impact on glycemic control in patients with type 2 diabetes. We therefore aimed to examine the longitudinal relationship between depression, behavioral factors, and glycemic control.

Methods: In a prospective component of a nationally representative sample, 866 patients with type 2 diabetes aged >or=18 years completed a standardized assessment including a laboratory screening, questionnaires, and diagnostic measures. Subsequent to baseline (t(0)), patients were tracked over a period of 12 months (t(1)). Depression was assessed according to DSM-IV and ICD-10 criteria. Glycemic control was determined by levels of glycosylated hemoglobin (HbA(1c)); a level of >or=7% was judged as unsatisfactory. Regression analyses were performed to analyze the prospective relationship between depression, medication adherence, diabetes-related health behavior, and HbA(1c).

Results: Patients with depression at t(0) revealed increased rates of medication nonadherence (adjusted OR: 2.67; CI: 1.38-5.15) at t(1). Depression (adjusted regression coefficient: beta = 0.96; p = 0.001) and subthreshold depression (beta = 1.01; p < 0.001) at t(0) also predicted increased problems with diabetes-related health behavior at t(1). Adjusted ORs for poor glycemic control (HbA(1c) >or=7%) at t(1) were also increased for patients with baseline depression (2.01; CI: 1.10-3.69). However, problems with medication adherence as well as problems with diabetes-related health behavior at t(0) did not predict poor glycemic control at t(1).

Conclusions: In a prospective representative study of patients with type 2 diabetes, baseline depression predicted problems with medication adherence, problems with health-related behaviors, and unsatisfactory glycemic control at follow-up.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Depressive Disorder / blood*
  • Depressive Disorder / diagnosis
  • Depressive Disorder / psychology*
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / drug therapy
  • Diabetes Mellitus, Type 2 / psychology*
  • Female
  • Glycated Hemoglobin / metabolism*
  • Health Behavior
  • Humans
  • Hypoglycemic Agents / administration & dosage*
  • Life Style
  • Longitudinal Studies
  • Male
  • Medication Adherence / psychology*
  • Middle Aged
  • Personality Inventory
  • Primary Health Care
  • Prospective Studies


  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • hemoglobin A1c protein, human