[Upward trend in the use of psychostimulants by adults].

Objective: To gain insight into the trends in the use of psychostimulants among adults.
Design: Retrospective database study.
Methods: We selected data on adults (≥ 18 years) who had had a minimum of 2 prescriptions for a psychostimulant drug within 1 year from IADB.nl, a Netherlands database of filled prescriptions (59 public pharmacies, approximately 600,000 patients). We calculated both the number of new users and the total number of users of psychostimulants per year in the period 2004-2014. We also assessed which agent was the most commonly prescribed psychostimulant drug and who had initiated treatment.
Results: The number of adults who were prescribed psychostimulants (methylphenidate, dexamphetamine and amphetamine) increased from 1.5 per 1000 adults in 2004 to 7.8 per 1000 adults in 2014. Users were mainly male (63.0%) and methylphenidate was the most frequently prescribed agent (85.7%). The number of new users of these agents increased from 0.5 to 1.5 per 1000 adults, and the greatest increase was observed among young adults (< 30 years). The increase in new users seems to have stabilized since 2012. Around 40% of new treatments were initiated by the GP.
Conclusion: The large increase in the number of adults who are prescribed psychostimulants seems mainly to be the result of an increase in the number of new users, especially among young adults. As psychostimulants are only approved for the treatment of ADHD in children from 6 years of age and in adolescents, short- and long-term effects and side effects of these drugs need to be better assessed in the adult population.