Co-Morbid Depression and Diabetes: A Collaborative Community Health Center Study

Chronic medical conditions such as heart disease, depression, and diabetes mellitus (DM) are responsible for 70% of death, disability, and healthcare cost in the United States. Depression is common in individuals with diabetes mellitus (DM). An estimated 41% of patients with DM experience poor psychological well-being, but only 12% of them reported receiving psychological treatment. Comorbid depression also adversely affects diabetes outcomes and decreases therapeutic adherence. Treating depression can improve treatment adherence and lead to improved DM control.

The study objective was to determine whether treatment of depression improved HbA1c levels in diabetic patients diagnosed with comorbid depression. This study involved a retrospective cohort chart review of all patients diagnosed with type 2 DM and comorbid depression as indicated by ICD-9 code groups 250 and 311. The charts of all patients diagnosed with type 2 DM and depression, between June 2014 and July 2015, were reviewed to extract the demographic characteristics, and to compare changes in glycosylated HbA1c levels (baseline to follow-up). The study groups were patients who received treatment for depression: antidepressant only group, behavioral health treatment group, antidepressant and behavioral health treatment group. Additionally, there was a control group that did not receive treatment for depression.

Ethical approval was received from Prairie View A & M University Institutional Review Board (IRB) and permission was obtained from the clinic’s medical director, administrative director, and information technology (IT) coordinators to conduct the review.

Of the 125 charts reviewed, only 85 were included in the final analysis. Participants in the sample were aged between 22 and 64 (m = 51.05, sd = 9.42). There were 42.4% of Hispanics, 29.4% of African Americans and 28.2% Caucasian. The decrease in average HbA1c level for the entire sample n = 85 between baseline and follow-up was statistically significant t (84) = -2.56, p = 0.012. One-way ANOVA test was utilized to test if average changes in HbA1c levels among groups were the same. No statistically significant differences among average changes in HbA1c levels across four groups were detected F (3,81) = 0.27, p = 0.85. Partial η² = .01 and achieved statistical power (9.9%) were very low. A nonparametric Kruskal-Wallis validated this conclusion (χ² (3) = 2.79, p= 0.42).

The study found a statistically significant decrease in HbA1c levels between baseline and follow-up in diabetic patients after receiving treatments for depression. The findings in this study further confirm the importance of treating depression in type 2 DM patients to lower HbA1c levels. However, the comparison of the four depression treatment groups showed no statistically significant effect in HbA1c levels across the groups.