ADHD medication use and long-term consequences

Abstract

There is ample evidence of the increasing use of ADHD medication, both in children and in adults. We found that the in The Netherlands, the overall incidence of ADHD medication use increased 6.5 fold in both males and females between 2001 and 2006. The major proportion of all treated patients comprised of 6-11 year old boys. Especially the use of the newly available long acting ADHD medication increased considerably. Many starters of ADHD medication discontinued early. Up to 60% of starters stopped using within 6 months, this however decreased to 45% since the availability of long acting ADHD medication. We studied ADHD patients younger than 19 years, referred to a center for mental healthcare between 1999 and 2010 with native Dutch, Moroccan, Turkish or Surinam ethnic background. We found that a higher proportion of ADHD diagnosed Moroccan (32.2%) and Turkish (42.3%) patients never used ADHD medication compared to Dutch natives (22.9%). Discontinuation of ADHD medication within 5 years was 2.4 fold higher in Moroccan and 1.6 fold higher in Turkish patients with ADHD compared to Dutch natives. A sensitivity analysis with a postal code matched comparison between Dutch natives and non-natives showed similar results, suggesting this effect is probably explained by ethnicity. We found, as expected, that the overall incidence of hospital admissions for injuries was two times higher in the ADHD medication cohort. We also found that the incidence rate for injuries during exposure to ADHD medication was lower compared to the period prior to ADHD medication use (not statistical significant). However, the overall risk in the ADHD cohort was higher than in control cohort with no history of ADHD medication use. Use of ADHD medication and concomitant psychotropics increased the risk for injuries compared to only ADHD medication use. In our 20+ year follow up study we described the association between past stimulant treatment and life time or daily illicit drug use in adults who were diagnosed with ADHD as a child or adolescent between 1984 and 2004, related to gender, IQ, psychological treatment, age of ADHD diagnosis, comorbid externalizing and internalizing disorders. We concluded that a history of stimulant treatment increased the risk for life time illicit drug use, particularly cannabis, in adults diagnosed with ADHD at childhood. Irrespective of stimulant use ever, a comorbid externalizing disorder diagnosed at young age (<19 years) increased the risk for life time use of illicit drugs in general and life time and daily cannabis use in adulthood. The later in life a subject was diagnosed with ADHD, the higher the risk for life time hard-drug use at follow-up, independent of stimulant use.