Understanding the ADHD Brain by looking at the science behind it. 

Part 1 of Our October ADHD Awareness Month Series

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that has fascinated scientists, clinicians and Adher’s alike for decades. As our understanding of the brain’s intricacies deepens, so too does our comprehension of ADHD’s underlying mechanisms. In this article, I look at the  latest in neuroscience related to ADHD. 

TL;DR

The neuroscience of attention-deficit hyperactivity disorder (ADHD) reflects a disorder that affects nearly every aspect of the brain: its structure, its functioning, and the way it connects different regions of the brain to communicate. Attention Deficit and Hyperactivity Disorder manifested in altered prefrontal cortex functionality, neurotransmitter deficiencies, and genetic predispositions; characteristic features that decidedly do not point to simple treatments. The Neuroanatomy of ADHD

At the heart of ADHD lies a complex interplay of the network of brain structures and functions. Neuroimaging studies consistently find differences in the brain structure and functions between individuals with ADHD, and those without ADHD.   These differences are most stark in areas related to attention, executive function and impulse control.

The prefrontal cortex, a region crucial for higher-order cognitive processes, often shows reduced volume and activity in individuals with ADHD. This area is responsible for executive functions such as planning, decisionmaking, and inhibitory control, all of which are frequently impaired in ADHD. The basal ganglia, a group of subcortical structures involved in motor control and learning, also demonstrate atypical functioning in ADHD brains.

Long-term studies have proved that these structural differences can persist into adulthood, even as symptoms sometimes improve, showcasing the permanence of neurobiological differences seen in ADHD.

Neurotransmitter Dysregulation

The dopamine hypothesis has propelled ADHD research for decades. According to this theory, aberrant signaling of dopamine in hindbrain circuits plays a major role in ADHD symptoms. Dopamine is important for motivation, reward processing, and attention, which is everything affected in those with ADHD.

However more recently studies have shifted this focus to additional neurotransmitters, especially noradrenaline. These are systems relevant to ADHD, and they reflect a more complex neurochemical processes that haven’t been fully explained yet.  

Genetic Factors in ADHD

ADHD most likely has a strong genetic basis, with twin studies showing heritability of 70 to 80%. Although researchers have not identified a single “ADHD gene,” they have discovered several genetic variants that may play a role in susceptibility to ADHD.

Impairments in executive function

The “conductor” of cognitive processes, executive functions are often inhibited in those with ADHD. These include working memory, inhibitory control and cognitive flexibility, all higher-order cognitive skills. Deficiencies in these areas may present as difficulties with planning, organization, time management, or emotional regulation.

Cognitive Processing Speed and ADHD

Processing speed, the rate at which an individual can take in information, make sense of it, and respond, is often slower in individuals with ADHD. This reduced processing speed can impact various aspects of cognitive functioning, from academic performance to social interactions.

ADHD and emotional dysregulation

Emotional dysregulation is increasingly being recognized as an important feature of attention-deficit hyperactivity disorder.  ADHDer’s frequently experience higher fluctuations in mood, than their peers, as well as more irritability, and heightened reactivity when it comes to emotional responses. This emotional instability can be deeply damaging to social relationships and self esteem.    Emotion regulation and executive functioning abilities have been associated.

The Role of Neuroplasticity

The idea of neuroplasticity, the ability of the brain to create new neural pathways and reform old ones, can give some hope to ADHDers. Studies show that the brain has the capacity to change over time in response to new experiences and interventions, reducing some of the neurobiological differences commonly.

More on Neuroplasticity coming on next posts.  

References for this Series