Psychological and personality factors in type 2 diabetes mellitus, preliminary results from The Maastricht Study

Miranda T. Schram, Fleur E.P. van Dooren, Frans R.J. Verhey, Simone J.S. Sep, Annemarie Koster, Pieter C. Dagnelie,  Johan Denollet, Frans Pouwer

Background:
Meta-analyses of longitudinal studies have shown that psychological variables such as depression and anxiety are associated with a higher risk for macro- and microvascular complications and higher mortality rates in individuals with type 2 diabetes mellitus (T2DM). Little is known about the role of specific personality traits in these associations. Therefore, we investigated the prevalence and associations of depression, anxiety and personality traits with T2DM in The Maastricht Study, a population-based cohort study.

Methods:
We measured current and lifetime depression using a diagnostic interview (MINI), and the PHQ-9, GAD-7, Type D (negative affectivity paired with social inhibition) and big five personality questionnaires in 858 participants of The Maastricht Study. 251 individuals had T2DM according to an oral glucose tolerance test. Logistic regression analyses was used to estimate the associations of depression, anxiety and personality with T2DM. Analyses were adjusted for age, sex and education level.

Results:
Individuals with T2DM had significantly higher levels of depressive symptoms, while the prevalence of current, life-time depression and anxiety levels were similar to individuals without T2DM (see table). Type D personality was more prevalent in T2DM, as were its two components negative affectivity and social inhibition. Individuals with type 2 diabetes were less extravert, conscientious, agreeable and emotionally stable, and similar in openness to individuals without T2DM.

Conclusion:
Individuals with type 2 diabetes experience more depressive symptoms and have less favorable personality traits, although the effect sizes of the latter are small. This may explain to some extend the adverse outcomes of type 2 diabetes with regard to macro- and microvascular complications and mortality in the presence of psychological distress.