Trends in and Predictors of Depression Among Participants in the Collaborative Initial Glaucoma Treatment Study (CIGTS)

Abstract

To characterize longitudinal trends and factors predictive of depressive symptoms following glaucoma diagnosis in Collaborative Initial Glaucoma Treatment Study (CIGTS) participants. Cohort study using follow-up data from a clinical trial. A total of 607 participants with newly diagnosed open-angle glaucoma were enrolled at 14 clinical centers in the United States from October 1993 through April 1997, randomized to treatment with medication or surgery, and followed every 6months through 2004. The 8-item Center for Epidemiologic Studies Depression Scale (CES-D) was administered at baseline and follow-up visits. Three outcome measures were investigated: overall CES-D depression score, presence of mild or worse depression (CES-D score ≥ 7), and number of depressive symptoms endorsed. The average baseline CES-D score was 2.4 (SD= 3.8), 12.5% of subjects reported symptoms associated with mild or worse depression, and 55.3% reported at least 1 depressive symptom. By 1 year posttreatment, depression measures decreased (1.5, 6.7%, and 38.4%, respectively), with modest decreases thereafter. Baseline factors predictive of mild or worse depression included worse vision-related quality of life (VRQOL) (odds ratio [OR]= 2.41), female sex (OR= 1.42), younger age (OR per 10 years younger= 1.24), and less than high school education (OR= 2.93); other outcomes showed similar results. Depressive symptoms decreased considerably during the first year after treatment initiation, but were elevated in those with impaired VRQOL. Given the potential of depression to reduce treatment adherence and thus increase the risk of glaucoma progression, eye care providers should ask patients about depressive symptoms, provide reassurance when appropriate, and make referrals as necessary.