The Comorbidity of Depression in Type 2 Diabetes
It has been reported previously that symptoms of depression are associated with nonadherence to diabetes self-care.
On average, a sample of patients with type 2 diabetes and clinical depression spent more than 3 years over the course of a lifetime experiencing major depressive episodes.
The study, which was published in Diabetes Care, was a secondary data analysis of Program ACTIVE (Adults Coming Together to Increase Vital Exercise). Program ACTIVE was a single-arm pilot and feasibility study conducted from 2006 to 2009 to evaluate a combination of cognitive behavioral therapy and community-based exercise to treat depression in adults with type 2 diabetes. Participants were recruited from rural Appalachian counties in southeastern Ohio and western West Virginia.
For this analysis, the researchers used the Structured Clinical Interview for DSM-IV-TR to assess history of depressive disorders at baseline, after intervention, and at 3-month follow-up in 50 participants. Mean age was 57.2 years, 68% were women, and all were white. Mean age at diabetes onset was 46 years, and mean duration of diabetes was 10.5 years.
The first episode of any depressive disorder occurred at a mean age of 41.7 years, with participants experiencing a mean of 2.3 lifetime depressive episodes, according to study results. All told, mean exposure to any depressive disorder was 71.1 months, with a mean episode duration of 30.9 months.
Collectively, participants reported 92 major depressive episodes, experiencing a mean 1.8 episodes over a lifetime. Each episode lasted an average of 23.4 months, for a mean total lifetime exposure to major depressive episodes of 43.1 months. Results also showed, however, that 69% of episodes were 19.3 months or shorter, while 31% lasted between 25 and 231.3 months. Only 2 episodes lasted longer than 100 months.
Eighteen participants also experienced 23 episodes arising from other depressive disorders, which were defined as depressive disorders that did not meet DSM-IV-TR criteria for major depressive disorder (eg, dysthymia, adjustment disorder with depressed mood, and simple bereavement). Mean length was 60.9 months, with an average total lifetime exposure of 77.8 months.
The researchers also reported trends in recurrence of depressive disorder. The second recurrence occurred sooner than the first recurrence (P =.002). Additionally, at 60 months, median time to second recurrence was considerably shorter than median time to first recurrence (128.5 months) among those who experienced at least 2 recurrences, according to the data.
Similarly, for participants who experienced at least 3 recurrences, time to the third recurrence was shorter than time to the first recurrence (18 months vs 70 months). This finding was not statistically significant (P =.07 for month >25), the researchers noted, but the median time to the third recurrence was 18 months compared with 62 months for median time to second recurrence (P <.007).
Further, for participants with at least 2 episodes, the second episodes were shorter than first episodes (median, 9 months vs 14 months; P =.048 for time longer than 5 months) and third episodes were shorter than first episodes (median, 8 months vs 25 months; P =.007 for time longer than 3 months) for those who had at least 3 episodes. Second and third episodes were not significantly different in length.
The researchers found no differences in time to first remission or length of first episode between participants who were diagnosed with depression before diabetes and those who were diagnosed with diabetes before depression.
“[C]linical depression poses a significant burden on adults and families with type 2 diabetes. Data from the first study to document depression episode and remission duration over the life course has shown that depression is a recurrent disorder that persists for prolonged periods and imposes a significant burden on patients with type 2 diabetes,” the researchers wrote. “Whether depression or type 2 diabetes is diagnosed first, depression in these patients requires consistent and progressive treatment to reduce and prevent the host of adverse consequences associated with prolonged exposure to these comorbid conditions.”
The researchers highlighted several study limitations, including the relatively small sample size, lack of diversity among participants, absence of a control group without diabetes, exclusion of those with suicidal ideation, and the inability to access medical records to verify use of prescribed antidepressants.
de Groot M, Crick KA, Long M, Saha C, Shubrook JH. Lifetime duration of depressive disorders in patients with T2D. Diabetes Care. 2016 Oct 11. doi:10.2337/dc16-1145 [Epub ahead of print]