SCHOENMACKER, G. H., Groenman, A. P. , Sokolova, E., Oosterlaan, J., Rommelse, N., Roeyers, H., Oades, R . D., Faraone, S. V., Franke, B., Heskes, T., Arias Vasquez, A., Buitelaar, J. K.,

Role of conduct problems in the relation between attention-deficit hyperactivity disorder, substance use, and gaming. 2018 European Neuropsychopharmacology, https://doi.org/10.1016/j.euroneuro.2018.06.003.

Abstract
Known comorbidities for ADHD include conduct problems, substance use disorder & gaming.
-- Comorbidity with conduct problems may increase the risk for substance use disorder & gaming in ADHD patients.

-- The aim of the study was to build a causal model of the relationships between ADHD & comorbid conduct problems, & alcohol, nicotine, & other substance use, & gaming habits, while accounting for age & gender.

0/ We used a state-of-the-art causal discovery algorithm to analyze a case-only sample of 362 ADHD-diagnosed persons aged 12-24 ys.

1/ We find that conduct problem severity mediates between ADHD severity & nicotine use, but not with more severe alcohol or substance use.

2/ More severe ADHD-inattentive symptoms lead to more severe gaming habits.

3/ Furthermore, our model suggests that ADHD severity has no influence on severity of alcohol or other drug use.

a) Our findings suggest that ADHD severity is a risk factor for nicotine use, & that this effect is fully mediated by conduct problem severity.

b) Finally, ADHD-inattentive severity was a risk factor for gaming, suggesting that gaming dependence has a different causal pathway than substance dependence & should be treated differently.

c) By identifying these intervention points, our model can aid both researchers & clinicians.