Comorbidity of ADHD with Substance use disorders

Abstract

Attention deficit hyperactivity disorder (ADHD) is characterized by inattention, hyperactivity and there is increasing evidence of deficits in motivation. Dysregulation of the nucleus accumbens dopamine system has been implicated in ADHD and in substance use disorder (SUD), so there is overlap of neurobiology of ADHA and SUD. Numerous studies have documented an increased risk for SUD in youth with untreated ADHD. Given this linkage, it is important to determine whether treatment of ADHD with stimulants could prevent SUD. Some untreated children with ADHD for the purpose of self-medication start using drugs and when ADHD treatment start, drug use stops. Therefore, diagnosis and treatment of ADHD will likely reduce risk for SUD, or at least improve its prognosis. From the other side, treatment with ADHD medications which are addictive does not affect an individual’s risk for developing a SUD if medications are taken orally, in therapeutic doses and in environmental context because they will not produce rapid increase of dopamine in reward region and filing of “high”. Amphetamine which is very similar to methamphetamine and methylphenidate which is very similar to cocaine influence dopamine in reward region and motivate people to sustain attention. Psychostimulants transforming boring task to more exiting, interesting and motivating. Regardless of what is primary inattention or motivation deficit in ADHD, these two dimensions could have common neurobiological substrates- dopamine reward pathway. Related to this some study suggests the need to consider the possibility of including "motivation or interest deficit" as part of the core pathology of ADHD.