How Attention Deficit Hyperactivity Disorder and Substance Use Disorder influence each other: A non-systematic literature review

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopment disorder characterized as a persistent pattern of inattention, hyperactivity, and/or impulsivity. Substance use disorder (SUD) is characterized by a problematic pattern of substance abuse leading to clinically significant impairment or distress. Prevalence of comorbid ADHD and SUD is high and over half of young people and adults diagnosed with ADHD also have SUD. Treatment of this comorbidity is challenging and the evidence still limited. Non-systematized literature review summarizing the comorbidity of ADHD and SUD as well as specificities of treatment and prognosis.

Children with ADHD are estimated to be 2.64 times more likely to develop SUD in adult. Such concurrent can be partly explained by common vulnerability factors, like genetic predispositions and dysfunctions in the inhibitory and reward system in the brain. Youth with ADHD are more likely to initiate substance use earlier and escalate to more frequent substance use. SUD contribute substantially to elevated mortality rates among patients with ADHD and predicts poorer outcomes and prognosis. Early recognition and treatment has the potential to change the trajectory of psychiatric morbidity later in life. Early research suggested that exposure to stimulants, first line treatment of ADHD, might increase risk of substance-related problems, however more recent studies demonstrated the opposite. Although stimulant medication does not seem to increase the risk for SUD, clinicians should remain alert to the potential problem of stimulant misuse and diversion in ADHD patients.

Despite the high rate of concurrent ADHD and SUD, the evidence regarding to the efficacy of treatments is limited and does not allow for strong recommendations. Future research is needed to determine how SUD can be a barrier to improved ADHD outcomes and to evaluate the efficacy of treatment both in ADHD-only patients and in patients with comorbid ADHD and SUD.