When children don’t pay attention, act impulsively, or are hyperactive - a doctor may diagnose ADHD and prescribe medication to help them have better focus, control their impulses and feel more calm.
There are a number of drugs available to help both children and adults with ADHD, but one in particular is catching the eye of researchers for its ability to also help people with Alzheimer’s disease.
In the 1980s, pathologists conducting autopsies on people who died of Alzheimer’s witnessed damage to the locus coeruleus, a region of the brainstem that produces norepinephrine, also known as noradrenaline. This neurotransmitter is important for cognitive functions including attention, learning, and memory.
Noradrenergic medicines were already available for other purposes to increase the amount of norepinephrine in the brain, so scientists were hopeful that they could help those with Alzheimer’s. However, several small trials failed to produce significant results, and as a result, interest diminished.
With the advent of more advanced imaging techniques that allow the locus coeruleus to be measured in living patients, scientists started to discover the value of ADHD medications in the fight against memory loss.
Modest Cognitive Improvement
Scientists based at Imperial College London, University College London, and the University of Cambridge published a review of the research in the Journal of Neurology, Neurosurgery and Psychiatry in July 2022.
The team analyzed nineteen clinical trials in patients with Alzheimer’s and mild cognitive impairment (MCI), settling on ten trials containing 1,300 patients that met their criteria. They found that the ADHD drugs did improve general cognitive ability compared to placebo. The effect was significant but modest.
Professor David Smith, Professor Emeritus of Pharmacology, University of Oxford, thought the change with the ADHD medication was “probably not clinically relevant.” But Dr. Andrew Reid, Assistant Professor of Psychology at the University of Nottingham, took a different view.
Dr. Reid believes the noradrenergic system “is a promising new avenue of research because there is a lot of accumulating evidence that this system is changed very early on in the disease, and that is exciting because it suggests a way to identify individuals at risk and treat them much earlier than is currently possible.”
Dr. Reid believes there’s “good evidence” that the effects ADHD drugs have by increasing levels of the neurotransmitter, norepinephrine, can really help patients.
But that’s not all. The review also examined the effects of ADHD drugs on what has been described as “the forgotten symptom of dementia,” even though it affects a high number of patients.
The London team looked at eight trials with a total of 425 patients to see if the ADHD drugs helped lack of motivation or apathy, a common symptom of dementia. This time there was a large improvement and was an important finding because no approved drugs treat this aspect of the condition.
Jim Ray at the University of Texas MD Anderson Cancer Center explained, saying, “If there was a treatment that could improve motivation, particularly in patients where that’s a really big concern, I think that would be extremely useful, and I think that’s the potential impact of this research publication.
Michael David at Imperial College London, who led the research, explained, saying, “I think these results certainly show promise with regards to the potential benefits in targeting this neurotransmitter system.
“Clearly, the drugs are not a cure, but people with Alzheimer’s can live for a long time, so, if you can make any difference, especially early on, then you have the potential to impact them and their loved ones for quite a few years.”
The London team was so encouraged by the results they’ve already started a trial to see if the ADHD drug guanfacine will help Alzheimer’s patients.