(HealthDay News) – There is a bidirectional relationship between type 2 diabetes and depression, with a stronger correlation for depression predicting diabetes onset, according to research published online Nov. 12 in Diabetes Care.
Pei-Chun Chen, PhD, of the National Taiwan University College of Public Health in Taipei, and colleagues conducted two cohort studies using the same database source to address the strength of the correlation for a bidirectional relationship between depression and type 2 diabetes. To analyze diabetes predicting depression onset, 16,957 patients with type 2 diabetes and an equal number of age- and sex-matched individuals without diabetes were assessed. To analyze depression predicting diabetes onset, 5,847 patients with depression and an equal number of control subjects without depression were evaluated. Participants were followed from 2000–2006.
In the first cohort analysis, the researchers found that the incidence density for depression was 7.03 per 1,000 person-years for those with diabetes and 5.04 per 1,000 person-years for those without diabetes, representing an adjusted hazard ratio of 1.43. In the second cohort, the incidence density for diabetes was 27.59 and 9.22 per 1,000 person-years in those with and without depression, respectively. The adjusted hazard ratio for incident diabetes was 2.02 in association with baseline depression.
“The two cohort studies provided evidence for the bidirectional relationship between diabetes and depression, with a stronger association noted for the depression predicting onset of diabetes,” the authors write.