Depression Increases With Diabetic Retinopathy Severity 

Depression rates are higher in patients with greater severities of diabetic retinopathy (DR), according to a recent study published in the American Journal of Ophthalmology. Individuals with moderate to severe nonproliferative diabetic retinopathy (NPDR) are more likely to experience depression than those with no diabetic retinopathy, mild NPDR, or proliferative DR.

Researchers conducted a study to investigate the relationship between diabetic retinopathy and depression and to assess patient’s knowledge of their DR diagnosis and the effect on depression using data from the 2005-2008 National Health and Nutrition Examination Survey (NHANES). Participants between the ages of 40 and 85 years were included if they had retinal imaging and grading and provided demographic data. The presence or absence of major depression was determined by the Patient Health Questionnaire-9 (PHQ-9).

The study included 90.4% of patients with no retinopathy, 8.2% with mild NPDR, 1.1% with moderate to severe NPDR, and 0.3% with proliferative DR. A total of 23.8% of patients with proliferative DR was below the poverty line, compared with 16.5% of patients with moderate to severe NPDR, 9% of patients with mild NPDR, and 9% of patients with no retinopathy. 

Major depression, as indicated by a PHQ-9 score of 10 or more, was present in 4.5% of patients with proliferative diabetic retinopathy, 15.7% of patients with moderate to severe NPDR, 6.1% of patients with mild NPDR, and 7.1% of patients with no retinopathy.

Multivariable logistic regression models showed lower odds of depression in those with mild NPDR than those without diabetic retinopathy with an OR of 0.79 (95% CI, 0.46-1.3), although these results are not significant. When adjusting for covariates, the odds of depression increased 2.5 times among those with moderate to severe NPDR.

When examining the connection between knowledge of DR and depression, 17% of individuals who reported having DR also experienced depression, while only 9% of those who did not report DR had depression. This pattern held regardless of whether or not the individual had accurate knowledge of their DR status.

“Our study found that the presence of moderate/severe NPDR has a 2-fold higher rate of depression after adjusting for demographic factors. Eye doctors, and in particular retina specialists, who see these patients in their clinics as often as once a month, should be aware of the strong association between DR and the development of depression,” according to the researchers.

Study limitations include the possibility that lower or higher cutoffs of the PHQ-9 score may better assess depression prevalence, and the NHANES does not account for smaller ethnic groups.