Major depressive disorder in patients with diabetes mellitus in Pietermaritzburg, South Africa.

BACKGROUND: Diabetes mellitus (DM) and major depressive disorder (MDD) constitute a major burden of disease. A study found that type 2 DM (DM2) is associated with a two-fold increase in risk of developing MDD worldwide - except in Africa. The present study challenges this statement.

OBJECTIVES: To determine the prevalence of MDD in a cohort of patients with DM and its effect on glycaemic control.

METHODS: A cross-sectional study was performed at a diabetes clinic at Edendale Hospital, Pietermaritzburg, South Africa (1 March - 31 May 2017). A total of 176 participants were enrolled. Participants completed the Patient Health Questionnaire-9 (PHQ-9), with a score of ≥10 representing a diagnosis of MDD. Higher PHQ-9 scores translate into more severe MDD. A surrogate for glycaemic control, glycated haemoglobin (HbA1c) blood testing, was also performed.

RESULTS: The majority of participants were female and suffered from DM2. The mean age was 54.4 years. The prevalence of MDD in the study population was 46.6%. A significantly positive linear relationship was shown between PHQ-9 score and HbA1c (p=0.018253).

CONCLUSIONS: MDD appears to constitute a large burden of disease in our population of individuals with DM. A relationship between the severity of the MDD and HbA1c suggests that prompt intervention in both conditions is likely to improve health outcomes.