Social deprivation in adolescence and risk of depression in young adulthood: a longitudinal analysis of linked administrative data from Northern Ireland.

Purpose: Socioeconomic deprivation may elevate the risk of depression. This study examines how the effect of area-level deprivation during adolescence on antidepressant prescribing varies by urbanicity in young adulthood in Northern Ireland. Methods: A cohort of 120,907 individuals aged 10-14 years in 2010 was tracked through to 2021 using linked administrative data. Antidepressant prescriptions were recorded annually; area-level deprivation was assessed in 2010 using the Northern Ireland Multiple Deprivation Measure (NIMDM). A random-intercept logistic regression model, with calendar year treated as a random effect, was used to analyse the relationship between area-level deprivation in 2010 and antidepressant prescribing from 2010 to 2021, adjusting for age, sex and urbanicity (urban/rural). The effect of area-level deprivation was allowed to vary by urbanicity. Analyses were repeated for different types of antidepressants. Results: 30,243 (25.0%) young people received antidepressants at least once over the study period. The likelihood of receiving antidepressants in the first year of the study (2010) was highest for young people residing in the most deprived urban areas (51, 0.23%) and lowest for those living in the least deprived rural areas (<10, <0.45%). After adjusting for confounders, the conditional probability of receiving antidepressants in 2021 for those living in the most deprived urban areas in 2010 was an estimated 20.3% (95%CI 20.0%, 20.7%), compared to 15.9% (95%CI 14.9%, 16.9%) who lived in the most deprived rural areas in 2010 and 14.8% (14.1%, 15.5%) who lived in the least deprived rural areas in 2010. Similar trends were observed for different types of antidepressants. Discussion: Urban environments may expose young individuals to additional risks, with early disadvantage leading to lasting mental ill-health effects. In contrast, rural areas may have fewer prescriptions due to limited access to healthcare and challenges in capturing localized rural deprivation using area-level measures. Conclusion: This study underscores the importance of targeted mental health interventions for deprived urban adolescents. Further research is needed to better understand the relationship between deprivation and youth mental health in rural areas.