Attention-deficit-hyperactivity disorder and reward deficiency syndrome

Summary & key facts

This paper reviews genetic research that links some gene variants to a weaker brain reward system, especially lower dopamine function. The authors suggest this low-dopamine trait can make people feel uncomfortable and seek out drugs or other rewarding behaviors to feel better. They call this wider pattern "reward deficiency syndrome," say ADHD may be one type of it, and propose early genetic testing and tailored supplements or drugs that raise dopamine or serotonin as possible ways to reduce symptoms — but these ideas are presented as hypotheses, not proven treatments.

Key facts:

• Researchers have found several genes that may increase the chance of having ADHD.
• The authors say many studies point to a problem in the brain's reward system, especially low dopamine activity, that could make people feel unpleasant and seek things that release dopamine.
• One specific gene variant, called the DRD2 A1 allele, is linked to fewer dopamine receptors in brain reward areas and is mentioned as a risk factor.
• The paper proposes a broader concept called reward deficiency syndrome, where certain gene variants raise the risk for addictive, impulsive, and compulsive behaviors, and suggests ADHD could be a behavioral subtype of this syndrome.
• The authors suggest that early genetic testing plus DNA-based, customized nutritional supplements for children might reduce ADHD-like behaviors, and that drugs that increase dopamine or serotonin could be useful as additional treatments for related problems — but these are hypotheses that need more evidence.

Abstract

Molecular genetic studies have identified several genes that may mediate susceptibility to attention deficit hyperactivity disorder (ADHD). A consensus of the literature suggests that when there is a dysfunction in the "brain reward cascade," especially in the dopamine system, causing a low or hypo-dopaminergic trait, the brain may require dopamine for individuals to avoid unpleasant feelings. This high-risk genetic trait leads to multiple drug-seeking behaviors, because the drugs activate release of dopamine, which can diminish abnormal cravings. Moreover, this genetic trait is due in part to a form of a gene (DRD(2) A1 allele) that prevents the expression of the normal laying down of dopamine receptors in brain reward sites. This gene, and others involved in neurophysiological processing of specific neurotransmitters, have been associated with deficient functions and predispose individuals to have a high risk for addictive, impulsive, and compulsive behavioral propensities. It has been proposed that genetic variants of dopaminergic genes and other "reward genes" are important common determinants of reward deficiency syndrome (RDS), which we hypothesize includes ADHD as a behavioral subtype. We further hypothesize that early diagnosis through genetic polymorphic identification in combination with DNA-based customized nutraceutical administration to young children may attenuate behavioral symptoms associated with ADHD. Moreover, it is concluded that dopamine and serotonin releasers might be useful therapeutic adjuncts for the treatment of other RDS behavioral subtypes, including addictions.

Topics

Attention Deficit Hyperactivity Disorder Bipolar Disorder and Treatment Neurotransmitter Receptor Influence on Behavior

Categories

Health Sciences Medicine Psychiatry and Mental health

Tags

Addiction Attention deficit hyperactivity disorder Dopamine Dopaminergic Dopaminergic pathways Medicine Neuroscience Psychiatry Psychology Reward system

Conditions & symptoms

Addiction ADHD Addiction or harmful habbits Difficulty focusing