Neurobiology of ADHD and Comorbidities

Neurobiological research indicates it is reasonable to consider ADHD as a condition that falls under the “reward deficiency syndrome” (RDS) diagnostic umbrella (Blum et al. 2008), as symptoms of poor concentration stem from the brain’s inability to release sufficient amounts of dopamine (DA) in areas of the frontal lobes and limbic system to provide a feeling of reward when applying and/or maintaining focus on tasks at hand.

DA is the neurotransmitter most linked to attention and the ability to experience pleasurable emotions and sensations; It allows for general feelings of wellbeing, tempering of unpleasant emotions, good concentration, and optimal thought organization. For this reason, certain individuals with ADHD are more likely to experience depression. They may also develop thrill-seeking behaviors and engage in risky activities that result in an increased release of dopamine, such as high-risk sports, gambling, hypersexual behaviors, excessive internet video gaming, aggressive behavior, drug use, excessive shopping, and binge eating. Since DA is fundamental to producing pleasure and it impacts the activity of natural opioids in the brain, it also helps decrease feelings of uneasiness and drug withdrawal. People with RDS are therefore at higher risk of addiction to recreational or illicit drugs, as they may have a harder time stopping them (Blum et al. 2008). Read more