Associations between Depressive Symptoms and Social Support in Adults with Diabetes: Comparing Directionality Hypotheses with a Longitudinal Cohort

Individuals with diabetes are at increased risk of elevated depressive symptoms, and social support has been identified as a key factor in the health of this population. Cross-sectional associations between depressive symptoms and social support have been demonstrated. Three classes of hypotheses differentially describe the direction of this association: (1) depressive symptoms influence social support, (2) social support influences depressive symptoms, and (3) reciprocal associations exist between depressive symptoms and social support. The aim of this study was to compare these hypotheses. Depressive symptoms and social support were measured via telephone survey in a large cohort study of individuals with diabetes (n = 1754) in Quebec, Canada. After baseline, data were collected annually for 4 years. Path models depicting each hypothesis, as well as a stability model containing only autoregressive effects, were generated, and model fit was compared with Akaike's Information Criterion (AIC). The reciprocal model was selected as the best fitting model because it had the lowest AIC. This model demonstrated that depressive symptoms predicted subsequent social support at all time points and that social support predicted subsequent depressive symptoms at most time points. It appears that the association between depressive symptoms and social support in people with diabetes is best characterized as reciprocal. Results underscore the importance of directly comparing competing hypotheses and offer a more accurate depiction of the association between depressive symptoms and social support among people with diabetes.