Age at Emergence of Gender Inequalities in Prescribed Psychotropic Use: A Longitudinal Retrospective Cohort Study

Abstract Gender inequalities in the prevalence and trends of psychotropic medication use are well documented, but longitudinal evidence on the age at which these inequalities emerge remains limited. This study aimed to identify the age at which gender inequalities in psychotropic medication use emerge and to examine how their onset and magnitude vary according to socioeconomic position. A retrospective longitudinal cohort study was conducted using electronic health records from 174,336 adolescents aged 9–11 years in the Spanish National Health System, followed from 2018 to 2024. First prescriptions of anxiolytics, hypnotics and sedatives (AHS) and antidepressants were identified Cumulative incidence was estimated using the Kaplan–Meier method, and age-specific hazard ratios (HRs) by sex were calculated using piecewise Cox models. Girls had a significantly higher risk of initiating psychotropic medication use from age 12 onwards for both AHS (HR = 1.24 [1.12–1.38]) and antidepressants (HR = 1.58 [1.29–1.93]), with the largest gender differences observed at age 14 (AHS: HR = 2.14 [1.99–2.42]; antidepressants: HR = 3.06 [2.70–3.48]). Gender inequalities in AHS use emerged one year earlier among adolescents from low-income backgrounds, whereas this pattern was not observed for antidepressant use. Studying the emergence of gender inequalities and the influence of socioeconomic position on psychotropic use enables the development of interventions to prevent a widening gender gap in mental health, which may persist throughout life.