Background: Previous Dutch studies showed increasing psychostimulant use, especially methylphenidate immediate-release (MPH-IR), between 1995 and 2003. In 2003 the extended-release (ER) formulation of MPH and in 2005 atomoxetine (ATX) were introduced in The Netherlands, which increased treatment options.
Objective: The aim of this study was to describe the change in incidence of attention-deficit/hyperactivity disorder (ADHD) drugs and the prescription profiles of patients younger than 45 years starting treatment with these medicines between 2001 and 2006.
Methods: Data were obtained from Dutch community pharmacies as collected by the Foundation for Pharmaceutical Statistics, covering 97% of all dispenses for prescription medicines to outpatients in The Netherlands.
Results: The overall incidence of ADHD drugs use increased 6.5-fold from 2001 to 2006 in men as well as in women. The absolute incidence was highest among 6- to 11-year-old boys. The percentage of first-time MPH-IR users decreased from 98.3% in 2001 to 75.9% in 2006. Likewise, MPH-ER use increased from 0% in 2001 to 18.9% in 2006, and ATX use increased from 0% in 2001 to 3.9% in 2006. The new nonstimulant drug ATX was prescribed more often to adults if they had been previously treated with selective serotonin reuptake inhibitors (SSRIs), benzodiazepines, or antipsychotics. Youngsters <17 years initiated on ATX were often previously treated with antipsychotics or clonidine/guanfacine.
Conclusion: These findings demonstrate an increase in incidence in use of ADHD drugs between 2001 and 2006 in The Netherlands. The major proportion of all treated patients comprised boys, 6-11 years old; most of them were treated with MPH-IR. In a few years time, the use of extended-release drugs as part of all ADHD drug prescriptions increased considerably, despite the lack of full reimbursement of these extended-release drugs. Psychostimulants and atomoxetine in children, adolescents, and adults are probably used to address different treatment needs.