Results of a study published in BMC Psychiatry showed that patients with type 1 diabetes (T1D) and patients with type 2 diabetes (T2D) had very different profiles of depression.
Eva O. Melin, MD, from Endocrinology and Diabetes, Department of Clinical Sciences at Lund University, Lund, Sweden, and colleagues aimed to examine the clinical presentation of depression in patients with T1D vs T2D, specifically in relation to self-reported depression, anxiety, alexithymia, obesity, and midnight salivary cortisol (MSC).
The researchers conducted a comparative, cross-sectional study and recruited 24 patients with T2D (31-59 years) and 148 patients with T1D (32-59 years) from a hospital diabetes outpatient clinic. Data on self-reported depression, anxiety, and alexithymia were collected with the Hospital Anxiety and Depression scale and Toronto Alexithymia Scale-20, and MSC, HbA1c, anthropometrics, and data from medical records were also collected. The researchers performed multiple logistic regression analyses.
They found that depressed patients with T2D had traits of atypical depression, whereas those with T1D and depression exhibited traits of melancholia. Differences in MSC secretion occurred as well. Depression in T2D was not associated with high MSC (≥9.3 nmol/L) or anxiety, but those patients did demonstrate a greater prevalence of alexithymia and obesity. In contrast, depression in T1D was associated with high MSC and anxiety and a low prevalence of obesity and alexithymia.
The study found depression in 25% of those with T2D and 12% of those with T1D, whereas high MSC was found in 38% and 22%, anxiety in 38% and 35%, and alexithymia in 25% and 13%, respectively.
In patients with T1D, 53% of those who were depressed had high MSC vs 18% of those who were not depressed, but there was no significant difference in MSC between depressed and nondepressed patients with T2D.
The alexithymia prevalence was 67% among depressed T2D patients vs 11% among those who were not depressed, whereas 83% of depressed patients with T2D but only 6% of depressed patients with T1D were obese. Anxiety rates also were higher in depressed patients with T1D compared with nondepressed patients (76% vs 30%).
The authors contend that these findings (obesity, alexithymia, lack of anxiety, and lack of increased MSC in those patients with T2D and depression compared with those who were not depressed) support the hypothesis that depressed patients with T2D are more likely to suffer from atypical depression. Likewise, the presence of anxiety, increased MSC, and low prevalence of obesity in T1D supports the hypothesis that those with T1D and depression tend to suffer from melancholia.
This study was limited by the small T2D population (only 24 patients vs 148 with T1D).
Melin EO, Thunander M, Landin-Olsson M, Hillman M, Thulesius HO. Depression differed by midnight cortisol secretion, alexithymia and anxiety between diabetes types: a cross sectional comparison. BMC Psychiatry. 2017;17:335.