University of Calgary researchers seek individualized non-drug treatment for ADHD

Fifteen-year-old Camryn Mitchell has Attention Deficit/Hyperactivity Disorder (ADHD).

“I can't focus, and I don't remember what I said before. I find I’m doing things and then suddenly my mind wanders off,” said Mitchell

“I have trouble with socializing, talking, (and) communicating.  Like, for some reason, I find it really hard to make plans and tell people - like my mom especially - that I've made plans.”

The grade 10 student from Okotoks is taking part in a pioneering study with University of Calgary Cumming School of Medicine researchers that combines advanced neuroimaging with non-invasive brain stimulation techniques, in a bid to unlock the mysteries of ADHD and create personalized treatment for Canadian children.

The team of researchers led by Pediatric Neurologist Kara Murias are using Transcranial Magnetic Stimulation (TMS), a non-invasive method that modulates brain activity in targeted regions.

“Our hypothesis is that select executive functions can be affected or intervened or improved if we stimulate the right part of the brain, “said Murias

“We are stimulating different parts of the brain, and then measuring the change in those different executive functions to see if we can tailor it to an individual's specific deficits, because not every kid with ADHD has the same executive function deficits," Murias added.

Neurotransmitters and symptoms

Participants in the study receive a single session of TMS, inducing a temporary change in brain excitability for a period of 30 to 60 minutes. The focus is to investigate the relationship between neurotransmitters and specific ADHD symptoms.

TMS has previously been used in adult treatments for depression and anxiety.

“We know that in adults who get TMS treatment for depression, or some other indications, that there is long term changes in the excitability and the function of the areas of the brain that stimulate," said Murias, who cautions that does not automatically mean the same results will be found in children.

“The common cliche in pediatrics is that ‘kids are not small adults’," Murias added. "We know that when we do something in a kid, we need to study it specifically to understand what it's like in kids, and in kids of different ages. Because school-aged kids, their brain is changing a lot. Adolescents brains are changing a lot too, for different reasons.”

Performing cognitive tasks

Using cutting-edge MRI techniques, researchers visualize the brain’s structure, functionality, and dopamine production. Participants, like Mitchell, perform cognitive tasks designed to assess executive functions, such as behavior regulation and attention control. That is followed by TMS applied to brain areas highlighted in the MRI data.

Bevin Wiley, a PhD candidate in neuroscience is working with Dr. Muria, and operating the TMS during the session with Mitchell.

“We are looking at different areas of the brain to see if we stimulate different areas," said Wiley.  "How does that have like a different effect on different kinds of executive functions or potentially different areas that may be an issue for children with ADHD?”

“If we can then target slightly different brain areas that represent certain problems for an individual, then we can help kind of personalize what might be best in treatment for ADHD.”

Widespread neurodevelopmental condition

ADHD is a prevalent neurodevelopmental condition. According to the Centre for ADHD Awareness, Canada in children across Canada, four to six per cent of adults and five to seven per cent of children, totaling approximately 1.8 million Canadians, or one of every 21 people in the country has the disorder.

It can lead to adverse long-term effects if left untreated. The genetic underpinnings of ADHD are well-documented, yet the link between how neurotransmitters dysfunction and the manifestation of ADHD symptoms remains elusive.

While current treatments, including stimulant medications, target specific neurotransmitters like dopamine and noradrenaline, they are not universally effective and can come with significant side effects.

Researchers are still recruiting subjects for the study. More information, including a registration form, can be found on the University of Calgary web site here.