Trends in attention-deficit and hyperactivity disorder (ADHD) medications among children and young adults in Ireland: a repeated cross-sectional study from 2005 to 2015

Objective: This study examined the prescribing patterns of attention-deficit hyperactivity disorder (ADHD) medications in Ireland between 2005 and 2015 in children, adolescents and young adults, and concomitant use of psychotropic medication.

Design: Repeated cross-sectional study.

Setting: Community setting using pharmacy claims data in Ireland.

Participants: Children and young adults aged 0-24 years.

Primary and secondary outcomes: Authorised medications used to treat ADHD during the study period, methylphenidate, dexamfetamine, lisdexamfetamine dimesylate and atomoxetine were extracted from a national pharmacy claims database. Dispensing of concomitant psychotropic medications including antipsychotics, anxiolytics, hypnotics/sedatives and antidepressants were examined.

Results: The number on any ADHD medication ranged from 1913 in 2005 to 4853 in 2015, and the prevalence rate per 1000 eligible population aged <25 years increased significantly over time from 5.61 (95% CI 5.36 to 5.86) in 2005 to 8.36 (95% CI 8.13 to 8.60) in 2015 (p<0.0001). Negative binomial regression showed significant changes over time for ADHD prescribing (p<0.001), with significantly higher rates across the different age groups. The rates overall were three to five times higher in males. There was a significant increase in the percentage on concomitant antidepressants from 2% in 2005 to 6% in 2015 (p<0.001).

Conclusions: There were significantly higher rates of ADHD prescribing in children/adolescents and a significant increase in the coprescribing of antidepressants. The reasons for the increase are unclear but may reflect increasing awareness and diagnosis of the condition.