Attention-deficit hyperactivity disorder and substance abuse. A review

This paper presents an overview of the history of the studies of mental health problems and substance use disorder (SUD) and the neurobiology and etiology of attention-deficit hyperactivity disorder (ADHD) and SUD. Additionally, we review the literature on the associations between ADHD and SUD, the association between stimulant treatment in patients with ADHD and the risk of SUD and the guidelines for clinical assessment and treatment of adolescents with ADHD and comorbid SUD. There is substantial evidence suggesting that patients with ADHD are at increased risk of SUD, and that comorbid conduct problems are strong predictors of SUD, but not responsible for the entire associated risk between ADHD and SUD. Dopamine is thought to be one of the key neurotransmitters involved in the pathophysiology of both ADHD and SUD. Methylphenidate has the dopamine transporter as its main target and brain circuits modulated by dopamine are involved in the development of addiction. Methylphenidate is the most commonly used pharmacological treatment for ADHD and, although this prescribed drug potentially can be abused, it actually seems to reduce the risk of SUD in patients with ADHD, rather than to increase the risk. Few studies have examined the risk of SUD in females with ADHD and some of them suggest a higher risk of SUD than in males with ADHD. However, more research is needed on these gender differences before any clear conclusions can be drawn.