Nooriyeh Garaei - Department of Genetic, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran.

Background and Aim : Attention deficit hyperactivity disorder (ADHD) is a pediatric neurodevelopmental disorder with a prevalence of 5% in children and adolescents and of 2.5% in adults. ADHD is associated with a significantly increased risk for substance use, abuse and dependence. Methods : In this review, key words ADHD, SUD and Biomarker which were used. Related studies assessed from 2013 to 2019 in Pubmed database.Results : Polymorphisms in genes such as DAT1, 5HTTLPR, D4DR4, and MAO-A have been linked to ADHD and susceptibility for opiate addiction. In drug addict parents and their offspring, genetic markers that can increase the sensitivity to ADHD and addiction were studied; Children of opiate-dependent mothers had a higher rate of ADHD compared to those of the opiate-dependent fathers. Serotonergic and dopaminergic risk alleles seem to be mainly related to opiate dependence with no effect on the occurrence of ADHD. People carrying those polymorphisms are susceptible to opioid addiction and not necessarily to ADHD. Adolescents with ADHD are known to be at significantly greater risk for the development of substance use disorders (SUD) compared to peers. ADHD is associated with a significantly increased risk for substance use, abuse and dependence. ADHD and cannabis use are partly determined by genetic factors; the heritability of ADHD is estimated at 70–80% and of cannabis use initiation at 40–48%. Conclusion : In line with previous evidence supporting the co-occurrence of these two traits and the increased risk for cannabis use in individuals with ADHD It estimated that individuals with ADHD are 7.9 times more likely to consume cannabis than individuals without an ADHD diagnosis.

ADHD, SUD, Biomarker