Changing patterns of treatment and prescribers of stimulants for children, adolescents and young adults with attention deficit hyperactivity disorder in New South Wales, Australia: evidence for a treatment bottleneck? - A database study

Objective: Investigate the treatment patterns and prescribers of stimulants for attention deficit hyperactivity disorder (ADHD) in young people in New South Wales (NSW).

Method: Longitudinal cohort study of persons born after 1983 and prescribed stimulants for ADHD as per the NSW Ministry of Health Controlled Drugs Data Collection. Results were analyzed descriptively: a) treatment prevalence by year; age; sex; b) speciality of prescribers over time; c) rate of transition from paediatrics to adult psychiatry. The main analysis covered 2003-2015, with data on general practitioner prescribing to 2023.

Results: Treatment prevalence rates were highest at age 10 (22.8 per 1000 person years), declining among teenagers and stabilizing in adulthood at 2.5 per 1000. The childhood male treatment predominance (4:1) resolved to 1.6:1 in adulthood. Paediatricians were the main prescribers until age 20. The average annual percent increase in prescribers was: adult psychiatry - 13%, general practice - 20%, paediatrics - 2.6%. Only 6.3% of treated children had transitioned to adult psychiatrists by age 25; 50% starting treatment with adult psychiatrists had no previous treatment records.

Conclusions: The proportion on treatment and the male predominance declined substantially with age. Future studies may determine whether increased prescribing by general practitioners and psychiatrists reduces treatment attrition during adolescence.