title: Pain and functional impairment as mediators of the link between medical symptoms and depression in type 2 diabetes.
abstract: BACKGROUND
  Among people with diabetes, depression is more common and is associated with greater morbidity and mortality. A better understanding of mechanisms underlying the link between poor health and depression is needed. Pain and functional impairment may account for the effect of poor health on depression in diabetes.
  
  
  OBJECTIVE
  The purpose of the study was to examine whether pain and functional impairment mediate the association between diabetes-related medical symptoms and depression in type 2 diabetes.
  
  
  METHODS
  Adults diagnosed with type 2 diabetes (N = 77) completed the following measures: Patient Health Questionnaire (PHQ), Diabetes Symptom Checklist (DSC), and Medical Outcomes Study 12-item Short-Form Health Survey (SF-12). Body mass index (BMI) was computed using height and weight data from medical records. Mediation and linear regression analyses were conducted.
  
  
  RESULTS
  Pain and functional impairment made significant, independent contributions to depression. Functional impairment mediated the link between diabetes-related medical symptoms and depression. Pain mediated the association between higher BMI and depression.
  
  
  CONCLUSIONS
  Pain and functional impairment appear to play important, independent roles in depression in type 2 diabetes. Mediation analyses suggest the following: 1. diabetes-related medical problems increase functional impairment, which in turn leads to greater depression; and 2. the burden of carrying greater body mass (higher BMI) increases pain, which leads to increased depression.
authors.affiliation: Department of Psychology, University of South Florida, Tampa, FL 33620, USA. sacco@usf.edu
authors.forename: William P
authors.initials: WP
authors.lastname: Sacco
authors.forename: Cathy A
authors.initials: CA
authors.lastname: Bykowski
authors.forename: Laura L
authors.initials: LL
authors.lastname: Mayhew
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D003863:Depression / Q000150:complications* / Q000523:psychology; D003866:Depressive Disorder / Q000150:complications* / Q000523:psychology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000523:psychology; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000150:complications* / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult