, Volume 53, Issue 12, pp 2480-2486

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Type 2 diabetes mellitus as a risk factor for the onset of depression: a systematic review and meta-analysis

  • A. NouwenAffiliated withSchool of Psychology, University of Birmingham Email author 
  • , K. WinkleyAffiliated withInstitute of Psychiatry, Kings College London
  • , J. TwiskAffiliated withEMGO+ Institute, VU University Medical Center
  • , C. E. LloydAffiliated withFaculty of Health and Social Care, The Open University
  • , M. PeyrotAffiliated withDepartment of Sociology, Loyola University MarylandDepartment of Medicine, John Hopkins University
  • , K. IsmailAffiliated withInstitute of Psychiatry, Kings College London
  • , F. PouwerAffiliated withCRPS—Center of Research on Psychology in Somatic diseases, Tilburg University
  • , for the European Depression in Diabetes (EDID) Research Consortium



An earlier meta-analysis showed that diabetes is a risk factor for the development and/or recurrence of depression. Yet whether this risk is different for studies using questionnaires than for those relying on diagnostic criteria for depression has not been examined. This study examined the association of diabetes and the onset of depression by reviewing the literature and conducting a meta-analysis of longitudinal studies on this topic.


EMBASE, MEDLINE and PsycInfo were searched for articles published up to September 2009. All studies that examined the relationship between type 2 diabetes and the onset of depression were included. Pooled relative risks were calculated using fixed and random effects models.


Eleven studies met our inclusion criteria for this meta-analysis. Based on the pooled data, including 48,808 cases of type 2 diabetes without depression at baseline, the pooled relative risk was 1.24 (95% CI 1.09–1.40) for the random effects model. This risk was significantly higher for studies relying on diagnostic criteria of depression than for studies using questionnaires. However, this difference was no longer significant when controlled for year of publication.


Compared with non-diabetic controls, people with type 2 diabetes have a 24% increased risk of developing depression. The mechanisms underlying this relationship are still unclear and warrant further research.


Critical review Depression Incidence Meta-analysis Systematic review Type 2 diabetes