No increase in long-term risk for nicotine use disorders after treatment with methylphenidate in children with attention-deficit/hyperactivity disorder (ADHD): evidence from a non-randomised retrospective study.
To evaluate long-term effects of methylphenidate (MPH) treatment in ADHD children on the development of nicotine use disorders (SUD-N). Multisite retrospective non-randomised longitudinal study with 215 ADHD children (diagnosis at 9.2 years of age; reassessment for SUD-N at 21.9 years of age) strictly parallel allocated to MPH treated (n = 106) and drug naive (n = 109) children. There was no difference between the groups with respect to frequency (84% MPH; 89% non-MPH; chi(2) = 1.6; p = 0.21) and age of onset for first cigarette smoking (log rank 1.68; p = 0.19). Continuous smoking was reached by 51% (MPH) and 61% (non-MPH) of the patients. Survival analyses revealed a small and nominally significant delay in age of onset for continuous smoking in the MPH-group (log rank = 3.85; p = 0.049). Nicotine dependency was reached by 20% (MPH) and 27% (non-MPH). Age of onset does not differ between groups (log rank = 2.24; p = 0.13). Limited evidence due to the non-randomised nature of the study is given that MPH does not induce SUD-N. The data suggests there may be a beneficial effect of MPH on delay of onset for continuous nicotine consumption in ADHD patients.