title: Depression, self-care, and medication adherence in type 2 diabetes: relationships across the full range of symptom severity.
abstract: OBJECTIVE
  We examined the association between depression, measured as either a continuous symptom severity score or a clinical disorder variable, with self-care behaviors in type 2 diabetes.
  
  
  METHODS
  We surveyed 879 type 2 diabetic patients from two primary care clinics using the Harvard Department of Psychiatry/National Depression Screening Day Scale (HANDS), the Summary of Diabetes Self-Care Activities, and self-reported medication adherence.
  
  
  RESULTS
  Of the patients, 19% met the criteria for probable major depression (HANDS score >or=9), and an additional 66.5% reported at least some depressive symptoms. After controlling for covariates, patients with probable major depression reported significantly fewer days' adherent to diet, exercise, and glucose self-monitoring regimens (P < 0.01) and 2.3-fold increased odds of missing medication doses in the previous week (95% CI 1.5-3.6, P < 0.001) compared with all other respondents. Continuous depressive symptom severity scores were better predictors of nonadherence to diet, exercise, and medications than categorically defined probable major depression. Major depression was a better predictor of glucose monitoring. Among the two-thirds of patients not meeting the criteria for major depression (HANDS score <9, n = 709), increasing HANDS scores were incrementally associated with poorer self-care behaviors (P < 0.01).
  
  
  CONCLUSIONS
  These findings challenge the conceptualization of depression as a categorical risk factor for nonadherence and suggest that even low levels of depressive symptomatology are associated with nonadherence to important aspects of diabetes self-care. Interventions aimed at alleviating depressive symptoms, which are quite common, could result in significant improvements in diabetes self-care.
authors.affiliation: Behavioral Medicine, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA. jsgonzalez@partners.org
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Gonzalez
authors.forename: Steven A
authors.initials: SA
authors.lastname: Safren
authors.forename: Enrico
authors.initials: E
authors.lastname: Cagliero
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Wexler
authors.forename: Linda
authors.initials: L
authors.lastname: Delahanty
authors.forename: Eve
authors.initials: E
authors.lastname: Wittenberg
authors.forename: Mark A
authors.initials: MA
authors.lastname: Blais
authors.forename: James B
authors.initials: JB
authors.lastname: Meigs
authors.forename: Richard W
authors.initials: RW
authors.lastname: Grant
mesh_terms: D000368:Aged; D003863:Depression / Q000150:complications*; D003865:Major Depressive Disorder / Q000150:complications*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000523:psychology* / Q000628:therapy*; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000523:psychology; D012307:Risk Factors; D012648:Self Care / Q000523:psychology*