Atlanta nurse with ADHD breaks down science behind the disorder

ATLANTA — Attention-deficit/hyperactivity disorder: As far as diagnostic nomenclature goes, it’s a mouthful. But for those suffering from ADHD, the difficulties go beyond a tricky name.

“‘My brain has way too many tabs open. Why can’t I complete tasks? Why do I lose track of time? Why can’t I pay attention?’ These are all things people with attention-deficit/hyperactivity disorder, or ADHD, may ask themselves daily, if not hourly,” Kate Harrington, MSN, APRN, FNP-C, told The Conversation.

A family nurse practitioner in primary care, Harrington works at Kennesaw State University’s Wellstar School of Nursing. And she’s not just an expert in adult ADHD; she’s been diagnosed with the condition herself.

Harrington is hardly alone. Around 4 percent of U.S. adults and 11.4 percent of U.S. children ages 3—17 suffer from the disorder. And according to a 2022 parent survey reported by the Atlanta-based Centers for Disease Control and Prevention, nearly 78 percent of children with ADHD also had another condition, such as anxiety or depression. And almost half of children diagnosed also had behavior or conduct problems.

But what precisely is ADHD?

“Put simply, ADHD significantly affects executive function,” Harrington explained. “Executive functioning is a set of cognitive processes, including planning, prioritizing, impulse control, flexibility, time management and emotional regulation, that help people achieve long-term goals.”

“These processes occur in the prefrontal cortex — the ‘personality center’ — of the brain,” she added.

ADHD also affects other areas of the brain, including the region used to regulate communication within the brain and the region used for movement and balance. The affected basal ganglia, cerebellum and prefrontal cortex work together to regulate a person’s attention, impulse control and more.

The way ADHD affects these regions of the brain comes down to neurotransmitters, the chemical messengers that allow brain cells to communicate with each other, particularly dopamine and norepinephrine.

“People with ADHD have lower levels of dopamine and norepinephrine in brain regions, including the prefrontal cortex. This leads to difficulty in sustaining cognitive functions such as attention, impulse control and motivation,” she said. “Studies show that people with ADHD have more dopamine transporters in the brain. Think of transporters as vacuums that suck dopamine back up into the neuron, making it less available.”

“As a result, there is less activation by dopamine and norepinephrine in the prefrontal cortex and the mesolimbic pathway, the area that processes rewards and motivation,” Harrington added. “Less dopamine can drive people to seek out stimulating rewards such as technology, food or drugs.”

Diagnosing the disorder comes down to identifying telltale symptoms, but also often requires a look back into a person’s childhood.

“If you struggle with ADHD, you have at least five to six symptoms in the inattentive, hyperactive or impulsive categories, such as forgetfulness, trouble sitting still, losing items and getting easily distracted,” she said. “For a formal diagnosis, ADHD symptoms need to have been present before the age of 12, something that can be determined in childhood or, as in my case, much later.”

“Also, ADHD symptoms must negatively affect the person in multiple settings, such as at home, in school or at work — and they can’t be explained away by other conditions, such as thyroid dysfunction, diabetes, sleep deprivation or anemia,” Harrington added.