In adults with type 2 diabetes (T2D), psychosocial factors, along with physiologic variables, are associated with the onset of major depressive disorder (MDD). Thus, a more holistic approach, which includes a discussion of life events, may help to identify those individuals in this population at risk for the development of psychological distress. Follow-up findings from the prospective International Prevalence and Treatment of Diabetes and Depression (INTERPRET-DD) study, conducted in 12 different countries, have been published in Epidemiology and Psychiatric Sciences.
The investigators sought to identify specific risk factors for the onset of diagnosed depression and depressive symptoms, in a cohort of patients with T2D. Between 2013 and 2015, a group of consecutive outpatient clinic attendees with T2D from each of the study sites was invited to participate in the study, with the goal of having 200 individuals with T2D from all 12 countries (ie, Argentina, Germany, India, Italy, Kenya, Mexico, Pakistan, Poland, Russia, Serbia, Uganda, and Ukraine). At each of the collaborating sites, the teams of investigators comprised at least 1 psychiatrist and 1 endocrinologist.
All eligible study participants were between 18 and 65 years of age and needed to have T2D diagnosed ≥12 months prior to the point of contact attending their diabetes outpatient facilities. All participants had to complete the Patient Health Questionnaire
(PHQ-9), the World Health Organization (WHO)-5 Well-Being Questionnaire, and the Problem Areas in Diabetes Scale (PAID). The PHQ-9 contains 9 items graded on a 4-point Likert scale. The WHO-5 is a 5-item scale that measures feelings of well-being, which identifies on a 6-point scale the absence of positive feelings, rather than the presence of negative feelings. The PAID is a 20-item questionnaire that measures the extent of diabetes-associated emotional distress. A composite stress score (CSS), which was defined as the occurrence of stressful life events and their reported degree of “upset,” between baseline and follow-up was calculated.
A total of 1616 participants had known MDD status at both baseline and follow-up. The participation rates varied by country, ranging from 55.6% in India to 98.5% in Ukraine, and by level of education (no formal education, vs primary, secondary, higher education). Those participants taking insulin were more likely to participate in follow-up data collection compared with those not on insulin (77.6% vs 72.0%, respectively; P <.01). Further, smokers were more likely than nonsmokers to participate in follow-up data collection (81.0% vs 73.2%, respectively; P <.01).
Overall, 7.4% incident cases of MDD were reported, with 81.5% of participants continuing to remain free of an MDD diagnosis. Per univariate analysis, those with MDD were more likely to be female, were less likely to be physically active, and were more likely to have diabetes complications at baseline and to have a higher CSS. Mean PHQ-9, WHO-5, and PAID scores were worse in participants with incident MDD compared with those with no diagnosis of MDD. Based on regression analysis, higher PHQ-9 scores, lower WHO-5 scores, and greater CSS were all significant predictors of incident MDD. Moreover, significant predictors of PHQ-9 included baseline PHQ-9 score, WHO-5 score, PAID score, and CSS.
The investigators concluded that stressful life events, diabetes-related distress, and depressive symptoms all play a key role in the development of MDD in patients with T2D and have implications for clinical practice. Encouraging individuals with diabetes to discuss stressful life events and to provide emotional support to these individuals may help to mitigate their risk for depression. Therefore, early screening and treatment of such symptoms among those with T2D is recommended.
Lloyd CE, Sartorius N, Ahmed HU, et al. Factors associated with the onset of major depressive disorder in adults with type 2 diabetes living in 12 different countries: results from the INTERPRET-DD prospective study [published online June 2, 2020]. Epidemiol Psychiatr Sci. doi: 10.1017/S2045796020000438