Estimation of Depression Prevalence in Patients with Stargardt Disease using PHQ-9 and Zung Scores

Abstract

To evaluate the psychological impact and depression prevalence in patients with Stargardt disease. We conducted a case-control study including 39 patients with Stargardt disease and 32 age- and sex-matched healthy controls. All participants underwent a complete ophthalmologic examination and completed the Patient Health Questionnaire-9 (PHQ-9) and the Zung Depression Inventory questionnaire. Results were analyzed using IBM SPSS 22.0 software. The patient group consisted of 19 men and 20 women with mean age of 36.9 ± 5.4 years and control group of 19 men and 13 women with mean age of 42.5 ± 10.1 years. The mean values of PHQ-9 and Zung scores for patients and healthy individuals were 10.9 ± 4.9, 46.7 ± 11.1, 6.7 ± 5.4, and 41.1 ± 8.5, respectively. There were statistically significant differences between the 2 groups in PHQ-9 scores (independent samples t test: p = 0.001), but not in Zung scores (Mann-Whitney test: p = 0.053). The PHQ-9 and Zung scores appeared to be moderately but significantly correlated (Pearson coefficient 0.44, p<0.0001). In addition, PHQ-9 score seems to be raised along with age, whereas both scores are low when best-corrected visual acuity is high. Patients with Stargardt disease exhibited more depressive symptoms compared to healthy individuals according mainly to PHQ-9 scores. Moderate depression was significantly correlated visual function decline.