Association between skin disorders and depression in children and adolescents: A retrospective case-control study

Background: The aim of this study was to investigate the association between skin disorders and depression in children and adolescents in Germany. Methods: This retrospective case-control study was based on data from the Disease Analyzer database (IQVIA). The present study included children and adolescents diagnosed for the first time with depression in 185 pediatric practices between January 2017 and December 2019 (index date) and matched controls without depression. Chronic skin conditions documented within 12 months prior to the index date (i.e. date of first depression diagnosis) were included in the analyses if their prevalence was at least 0.5% in the study population. Associations between nine different skin disorders and depression (dependent variable) were analyzed in a conditional logistic regression model. Results: This study included 7,061 cases with depression and 7,061 matched controls without depression (mean age 11.3 (SD: 3.8) years; 53.4% female). Three disorders were significantly associated with depression: atopic dermatitis/eczema (OR = 1.50, 95% CI = 1.37-1.64), nail disorders (OR = 1.84, 95% CI = 1.20-2.82), and hair loss (OR = 1.84, 95% CI = 1.30-2.60). In sex-stratified regression analyses, atopic dermatitis/eczema (OR = 1.43, 95% CI = 1.26-1.61) and hair loss (OR = 2.04, 95% CI = 1.37-3.03), were significantly associated with depression in females, since only atopic dermatitis/eczema was associated with depression (OR = 1.58, 95% CI = 1.39-1.80) in males. However, strong non-significant association was additionally observed for nail disorders (OR = 2.07, 95% CI = 1.07-4.01), and pigmentation disorders (OR = 1.93, 95% CI = 1.05-3.54) in females. Conclusions: Some skin disorders are positively associated with depression in children and adolescents. Further research is needed for better understanding of the underlying mechanisms and mediating factors.