LAUSR

Abstract We examined the association between mood disorders and risk of herpes zoster in two case‐control studies using data from nationwide Danish registries and practices in the UK Clinical Practice Research Datalink. We included incident zoster cases diagnosed in general practice (using systemic antivirals as a proxy in Denmark) or hospital during 1997‐2013 in Denmark (n = 190,671) and during 2000‐2013 in the United Kingdom (n = 177,361). We risk‐set sampled 4 matched population controls per case. Conditional logistic regression analyses adjusting for zoster risk factors showed that the odds ratios for previous mood disorder among cases versus controls were 1.15 (99% confidence interval (CI): 1.12, 1.19; prevalence 7.1% vs. 6.0%) in Denmark and 1.12 (99% CI: 1.11, 1.14; prevalence 31.6% vs. 29.2%) in the United Kingdom. In Denmark, odds ratios were higher for anxiety (1.23; 99% CI: 1.17, 1.30) and severe stress and adjustment disorder (1.24; 99% CI: 1.18, 1.30) than for depression (1.11; 99% CI: 1.07, 1.14). In the United Kingdom, odds ratios for these conditions were similar: 1.12 (99% CI: 1.10, 1.13), 1.12 (99% CI: 1.10, 1.14), and 1.14 (99% CI: 1.10, 1.19) for depression, anxiety, and severe stress and adjustment disorder, respectively. In conclusion, mood disorders were associated with an increased risk of zoster.