Alopecia Areata as a Proximal Risk Factor for the Development of Comorbid Depression: A Population-based Study.

Alopecia areata and depression tend to co-occur; however, their temporal association has not been comprehensively investigated. The aim of this study was to examine the temporal association between alopecia areata and depression. The study included only cases with a comorbid presentation of alopecia areata and depression (n = 1,936), extracted from the databases of the Clalit Health Services, Israel. Survival analyses were used to assess the cumulative probability of receiving alopecia areata as comorbid diagnosis in the years following depression, and vice versa, compared with the opposite trajectory. The results indicate that patients with alopecia areata had greater odds of subsequent depression within 2 years from alopecia areata diagnosis, and showed a steeper increase in cumulative probability of depression as time progressed (log-rank =336.38, p < 0.001), compared with the opposite trajectory. All patients with alopecia areata had comorbid depression within 10 years of alopecia areata, compared with 70% of depression patients receiving diagnoses of comorbid alopecia areata within the same time-frame.