Use of antidepressant drugs, alone or in combination with other psychotropic drugs, among five-year childhood cancer survivors in a Nordic setting: A register-based cohort study from the SALiCCS research programme

Background Childhood cancer survivors are at increased risk of psychological distress, yet population-level evidence on their long-term use of antidepressants remains limited. We aimed to assess the risk of antidepressant use, alone and in combination with other psychotropic drugs, among childhood cancer survivors. Methods This Nordic cohort study included 5-year survivors of childhood cancer diagnosed between 1990 and 2015 in Denmark, Finland, and Sweden. Antidepressant use was assessed using national registry data through December 31, 2022. For comparison, we randomly selected population references matched on year of birth, sex, and country, and identified all siblings of the survivors. We estimated cumulative hazards of antidepressant use alone and in combination with other psychotropic drugs and used Cox models to calculate adjusted hazard ratios (aHRs) with 95% confidence intervals (95%CI). Findings The study population included 11,026 childhood cancer survivors, 52,422 population references, and 13,304 siblings. Childhood cancer survivors had a moderately elevated risk of antidepressant use compared with population references (aHR = 1·26; 95% CI=1·20–1·33). Survivors also had a longer average duration of antidepressant exposure and an increased risk of concurrent use of antidepressants with other psychotropic drugs (aHR = 1·26; 95% CI=1·17–1·36) compared with population references. In the sibling comparison, results were broadly similar, showing an increased risk for antidepressant use alone (aHR = 1·23; 95% CI=1·15–1·31) and for concurrent psychotropic drug use (aHR = 1·24; 95% CI=1·12–1·37) in childhood cancer survivors. Interpretation This registry-based cohort study provides robust evidence of a modest but statistically significant increased risk of antidepressant use alone or in combination with other psychotropic drugs among childhood cancer survivors compared to the general population.