Depression and hemoglobin A1c in type 1 and type 2 diabetes: the role of self-efficacy.
OBJECTIVE
To examine a self-efficacy explanation of the finding that depression is related to hemoglobin A1c (A1c) level in people with type 1 but not type 2 diabetes.


METHODS
Cross-sectional design involving 124 participants with type 1 (n=32) and type 2 (n=92) diabetes. Participants completed measures of depression and diabetes-related self-efficacy. A1c was obtained from medical records.


RESULTS
Replicating prior findings, A1c was significantly correlated with depression in type 1 participants (r=.51, p<.01), but not in type 2 participants (r=.11, ns). As hypothesized, A1c was significantly correlated with self-efficacy among type 1 participants (r=-.42, p<.05) but not among type 2 participants (r=-.01, ns). Self-efficacy also mediated the effect of A1c on depression among the type 1 participants (Z=2.21, p<.05).


CONCLUSIONS
In people with type 1, but not type 2 diabetes, A1c levels are related to diabetes adherence mastery (self-efficacy), which mediates the link between A1c and depression. Results are discussed with regard to the proposal that perceptions of ineffective control over one's health play a role in the development of depression (a consequence model of depression in diabetes).
Sacco
William P
WP
Department of Psychology, University of South Florida, Tampa, FL 33620, USA. sacco@cas.usf.edu
Bykowski
Cathy A
CA
D001786:Blood Glucose / Q000378:metabolism; D003863:Depression / Q000097:blood* / Q000145:classification / Q000523:psychology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000523:psychology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000523:psychology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020377:Self Efficacy; D011795:Surveys and Questionnaires
D001786:Blood Glucose; D006442:Glycated Hemoglobin