Prescription rates for attention deficit hyperactivity disorder (ADHD) drugs in the UK increased by almost 800 per cent between 2000 and 2015, new research suggests.

Researchers used the Clinical Practice Research Datalink to identify 7,432,735 patients aged six to 45 years, registered with a GP between January 1995 and September 2015. They also identified 698,148 prescriptions for ADHD medications (methylphenidate, dexamphetamine, lisdexamphetamine and atomoxetine) during 41,171,528 person-years of follow-up.

During 1995, the pres-cription rate was just 4.8 per 10,000. By 2000, this had risen to 42.7 ADHD prescriptions per 10,000 persons and increased further to 394.4 per 10,000 in 2015.

After adjusting for age and sex, the prescription rate had increased by almost 800 per cent between 2000-15. The increase occurred in all age groups and in both sexes but was most marked in boys aged 10 to 14 years, when rates peaked: 2,184.6 per 10,000 received ADHD drugs during 2014.

ADHD drugs seem to be prescribed more quickly than in the past: in 1995, 16.8 per cent of patients were treated with an ADHD drug within one year of diagnosis, rising to 38.9 per cent in 2000 and 55.6 per cent in 2014.

The rise may reflect increases in ADHD diagnoses, a greater proportion of patients receiving ADHD drugs, longer duration of use and more frequent off-label prescription. The researchers comment that more research is needed to ascertain whether the clinical profile and mental health impairment of patients diagnosed and treated for ADHD have changed over time.

^{(Br J Clin Pharmacol DOI:10.1111/bcp.13000)}