Trends in the Dispensing of Adult ADHD Medications

Abstract

Aims
To examine patterns of stimulant ADHD medications to adults in Ireland between 2015 and 2024, under community drug schemes. We aimed to describe changes over time across age groups, demographic characteristics, and geographic areas.

Methods
Dispensing data were obtained from the Irish Primary Care Reimbursement Service, namely prescriptions reimbursed through General Medical Services scheme and Drug Payment scheme. Dispensing volumes and patient numbers for NICE-recommended first-line agents, methylphenidate and lisdexamfetamine, were analysed using a retrospective repeated cross-sectional design.

Results
The number of recorded dosage units of both medications increased by ~211% (700,574 to 2,217,634) between 2015 and 2024. Units of lisdexamfetamine rose by ~504% (59,088 to 356,641) between 2020 and 2023. The number of patients also increased during this time (3,377 to 13,966). Adults aged 16-34 years experienced the largest growth. By 2024, dispensings among females had increased to levels approaching those observed in males. Regional patient variation was evident, with largest increases observed in North Cork, Waterford, and Cork-South Lee.

Discussion
Adult ADHD pharmacotherapy in Ireland appears to have increased over the past decade, which could reflect evolving service provision. Demographic and regional variation could underscore the need for equitable expansion of adult ADHD assessment and treatment services.