ADHD, Neuroanatomy, and Neurological Considerations

Introduction

Anyone who has struggled with ADHD can tell you it is a real problem in many areas of their lives. With a new school year firmly underway, those struggles become more apparent and often teachers are the first to point out a problem may exist. While ADHD is often noticed and diagnosed in childhood, It Is Not Just for Kids! These problem areas first present in childhood, but many adults deal with them, too. Unresolved childhood ADHD becomes adult ADHD.

If you are reading this blog, you probably already want to yell, “Dr. Jula! I know I (or my child) have ADHD, but what do I do about it?” The purpose of this blog is to educate you about what ADHD is and what is happening in the brain. Some treatment strategies will be included later, but the short answer of what to do about it is to work with a healthcare provider along with knowledgeable educators (teachers, school counselors, special education staff, school psychologists, etc.). This blog – hopefully – will better prepare you for those discussions and meetings.

ADHD and Executive Functioning

What are we talking about when we bring up the topic of ADHD? ADHD is short-hand for AttentionDeficit/Hyperactivity Disorder. This diagnosis, found in the American Psychiatric Association’s DSM-5, has several sub-types: Predominantly inattentive presentation, Predominantly hyperactive/impulsive presentation, and Combined presentation.

What are we really talking about? When talking about any disorder one must consider the practical impact on the individual’s life. What are the functional deficits? What is more difficult for this particular person compared to their peers? In the case of ADHD, the “laundry list” of difficulties or deficits can be summed up as Executive Functioning. These types of cognitive abilities can be thought of as higher order processes that orchestrate other abilities – like an executive in an office running all the varying tasks in a business.

Executive functions can be divided into abilities involving organization and regulatory abilities. A comprehensive summary of these abilities from the UCSF Weill Institute for Neurosciences: Organization includes gathering information and structuring it for evaluation. Regulation involves evaluating the available information and modulating your responses to the environment.

• Organization – attention, planning, sequencing, problem-solving, working memory, cognitive flexibility, abstract thinking, rule acquisition, selecting relevant sensory information
• Regulation – initiation of action, self-control, emotional regulation, monitoring internal and external stimuli, initiating and inhibiting context-specific behavior, moral reasoning, decision-making

Individuals who have been diagnosed with ADHD struggle with any combination of these cognitive abilities. That can mean anything from difficulty sustaining focus (especially on non-preferred tasks), missing details and making careless mistakes, needing instructions repeated, disorganized materials or belongings, losing items, forgetfulness, speaking out of turn, excessively, or even rudely (no filter), excess energy and moving about, and difficulty waiting their turn. An often underrecognized area of struggle is managing emotions and expression of mood. This can present as anger and irritability to tearfulness and depressive symptoms. Some of these areas are more difficult at younger ages but improve with age and maturity (why deficits are measured relative to peers and why some people “grow out” of these struggles).

Where in the Brain?

What are the parts of the brain associated with executive functioning? The brain has evolved over time with certain elements common to most animals and others more developed and found in more sophisticated animals (such as humans). Executive functioning is along the lines of higherordered processes and the structures involved are located predominantly in the prefrontal cortex – the part of the brain most towards the front and part of the frontal lobe.

When we look at the brain in terms of functionality there are two major factors: structure and connection. A good reference for understanding neurological differences in children diagnosed with ADHD can be found at the Child Mind Institute (https://childmind.org/article/how-is-the-adhdbrain-different/).

Research indicates structures within the prefontal cortex to be smaller and less developed in children diagnosed with ADHD compared to typical development in the brains of age-mates. The cerebellum, hippocampus, and amygdala are also thought to be smaller in volume in kids with ADHD. Additionally, studies using fMRI technology have shown irregular activity in several regions of the brain involved in motor, cognitive, and emotional regulation.

Many parts of the brain have multiple roles and are involved in carrying out different functions. As it pertains to ADHD, the cerebellum is involved in regulating movement. A smaller cerebellum could contribute to inhibiting movements that interfere with task completion (like remaining seated in school). A smaller hippocampus and amygdala might cause diminished ability in the regulation of memory, emotion, and behavior.

Lastly, irregular patterns of connectivity between different parts of the brain may indicate dysfunction. Have you ever heard the saying, “Neurons that fire together, wire together”? Networks exist to complete the different functions of the brain – established wiring patterns connecting parts of the brain working together to complete tasks. Certain networks are over or under active in the brains of people exhibiting symptoms of ADHD. (See the previously referenced article from the Child Mind Institute)

Neurotransmitters

How does the brain talk to itself? The cells of the nervous system are called neurons. Communication takes place through electrical and chemical signals transmitted from one neuron to the next. Between two neurons is a small gap called the synapse. For a signal to pass from one neuron to the next it must “jump” the synaptic gap, an action facilitated by chemicals called neurotransmitters.

The neurotransmitter most often discussed in a conversation about ADHD is dopamine. Dopamine is part of many different neurological activities. This neurotransmitter passes from one region of the brain to the next via pathways in order to facilitate communication. The two dopamine pathways that are thought to play a part in the functional struggles associated with ADHD are the dopamine reward pathway and the mesocortical pathway.

The dopamine reward pathway, not surprisingly, is involved in the reward process of enjoying a pleasurable experience. An increased amount of dopamine is released along this pathway and activates feelings of pleasure and euphoria when we engage in such an activity. The mesocortical pathway connects an area of the brain that’s rich in dopamine to the prefrontal cortex. The prefrontal cortex uses dopamine to carry out executive functions. Research suggests disruptions in these two pathways occur in the brains of people diagnosed with ADHD and can lead to weakening of cognitive and motivational functioning. In essence, there is not enough dopamine available to facilitate typical functioning.

Creating Available Dopamine

How do we solve the problem of dopamine shortage? Most commonly people diagnosed with ADHD are prescribed medication to address the deficit. These prescriptions are most often stimulant medications which cause an increase in the synthesis of dopamine and therefore norepinephrine. Non-stimulant medication options promote availability of the neurotransmitter by inhibiting the breakdown of norepinephrine.

Oddly enough, activities that require dopamine to execute cause production of the neurotransmitter. In short, try to do some of the difficult activities to promote the synthesis of dopamine; however, do not throw yourself into these activities to the point of frustration as that would be self-defeating. Dopamine is required in the signaling from the brain to muscles to carry out movement. Exercising promotes neurotransmitter production, but the addition of other movements can also promote the chemical. While impulsivity and difficulty regulating energy can result in excessive movement, sometimes the extra bit of movement acts as a compensatory strategy to aide in paying attention. The processing of sensory information, especially novel stimuli, can promote dopamine. This is why fidgets tend to help people with ADHD. I’ve also recommended kids have a rough piece of adhesive Velcro in or on their desk to rub as a way of increasing novel stimuli to process.

The Cleveland Clinic provided suggestions for increasing dopamine production: a diet high in magnesium and tyrosine-rich foods as well as engaging in enjoyable activities that leave you feeling happy and relaxed. Foods known to increase dopamine include chicken, almonds, apples, avocados, bananas, beets, chocolate, green leafy vegetables, green tea, lima beans, oatmeal, oranges, peas, sesame and pumpkin seeds, tomatoes, turmeric, watermelon and wheat germ. The
Cleveland Clinic also endorses some supplements to raise dopamine levels. These include: Tyrosine, L-theanine, Vitamin D, B5 and B6, omega-3 essential fatty acids, and magnesium.(https://my.clevelandclinic.org/health/articles/22588-dopamine-deficiency)

That’s a Wrap!

Hopefully, you have a better understanding of ADHD. It is a neurological condition and requires neurologically informed treatment strategies. I did not include links to the numerous ADHD selfassessment tools out there because if you have read this far you already have a strong inkling you or a loved one meet criteria for an ADHD diagnosis. Also, ADHD should be assessed formally by a trained professional and not only from online self-report quizzes.