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Scientists say noradrenergic drugs may be helpful in treating Alzheimer’s disease. Tom Werner/Getty Images
  • Researchers say some noradrenergic drugs used to treat conditions such as attention deficit hyperactivity disorder and depression may have some benefits in helping with symptoms of Alzheimer’s disease.
  • They said the drugs show some small but significant positive effects on cognition, memory, and apathy for people with Alzheimer’s.
  • Experts caution, however, that these drugs do have side effects and a health professional should be consulted before they are used.

Noradrenergic drugs used to treat attention deficit hyperactivity disorder (ADHD), depression, and high blood pressure might have some benefits when used in people with Alzheimer’s disease, according to a new review of studies published in the Journal of Neurology, Neurosurgery & Psychiatry.

However, experts told Healthline that these drugs do have side effects and sometimes limited benefits, so a health professional should be consulted before taking them.

In their review, researchers looked at studies published between 1980 and 2021 that focused on the potential of noradrenergic drugs being used to treat neurodegenerative diseases.

In all, the scientists found 19 studies involving 1,811 participants. Of these, they deemed six studies were of good quality, seven were fair quality, and six were poor quality.

The scientists first reviewed and analyzed the results of 10 studies involving 1,300 people. These studies focused on global cognition, including orientation/attention, memory, verbal fluency, language, and visuospatial ability.

In studies that used the Mini-Mental State Exam or the Alzheimer’s Disease Assessment Scale to assess global cognition, the researchers said they found a small but significant positive effect of noradrenergic drugs on overall cognition.

Eight additional studies involving 425 people focused on behavior and neuropsychiatric symptoms, including agitation and apathy. The scientists said they found a significant positive effect of noradrenergic drugs on apathy.

“Alzheimer’s disease is a serious condition that impacts cognitive health, mood, behavior, and even physical health,” Dr. Mahmud Kara, a physician who founded KaraMD, told Healthline.

There is no cure for Alzheimer’s. It is a progressive disease that slowly destroys memory and cognitive skills. It can also interfere with a person’s ability to carry out daily tasks.

Noradrenergic drugs include atomoxetine, methylphenidate, and guanfacine. They target the neurotransmitter noradrenaline (norepinephrine), which is released in the brain by a network of noradrenergic neurons.

This network is critical in arousal and cognitive processes, including attention, learning, memory, readiness for action, and suppression of inappropriate behaviors. Noradrenergic disruption occurs early in Alzheimer’s and contributes to cognitive and neuropsychiatric symptoms.

Currently, the treatments for Alzheimer’s only slow the progress of the disease.

“The use of noradrenergic drugs could be another useful avenue for practitioners when treating [Alzheimer’s] symptoms,” said Kara. “However, we need to remember that these are a group of medications with potentially serious side effects and are usually not recommended for the elderly. Side effects include, but are not limited to, irregular heartbeat, high blood pressure, confusion, shortness of breath, and risk of addiction.”

“Apathy is a behavioral symptom we frequently see in [Alzheimer’s] and other dementias. The individual has limited interest in planning or participating in activities or events they previously would have found pleasurable,” said Abraham Brody, Ph.D., RN, FAAN, an associate professor of nursing and medicine and associate director of the Hartford Institute for Geriatric Nursing at NYU Rory Meyers College of Nursing.

“The only remarkable finding that has clinical meaning is using stimulants such as methylphenidate for cases of apathy,” Brody told Healthline. “I would only recommend these in narrow cases where apathy is a significant symptom and has major effects on the person’s quality of life.”

Experts say many people underestimate how much of a role apathy plays in Alzheimer’s. It is the most common neuropsychiatric symptom in people with Alzheimer’s, according to an article published in 2018 in the journal Current Opinion in Behavioral Sciences.

The article also notes that apathy is associated with more significant caregiver stress, decreased quality of life, and increased morbidity. It can start early in the disease progression. Once it starts, it continues to progress.

“Having effective treatment options for apathy, especially early in the disease process, would significantly improve the quality of life for patients and their families,” said Dr. David Merrill, a geriatric psychiatrist and director of the Pacific Neuroscience Institute’s Pacific Brain Health Center at Providence Saint John’s Health Center in Santa Monica, California.

“Decreasing apathy could also lead to more social and cognitively stimulating activities, which could help slow the decline by building up and preserving cognitive reserve,” Merrill told Healthline. “So, even if the medications don’t significantly impact cognition and memory, they could spur additional therapeutic lifestyle activities that benefit the brain.”

As with any treatment, doctors, patients, and caregivers should weigh the potential benefits against the risks. One significant side effect of stimulants is the disruption of healthy sleep habits.

“As a sleep specialist and psychiatrist, I cannot underscore enough the power of restorative sleep, especially for people with [Alzheimer’s]. I have seen some substantial improvements in cognition by improving sleep quality and duration,” said Alex Dimitriu an expert in psychiatry and sleep medicine and the founder of Menlo Park Psychiatry and Sleep Medicine in California as well as Brainfood MD.

“I would certainly consider a low-dose trial of stimulant medication taken early in the day,” Dimitriu told Healthline. “I want to minimize medical risks by monitoring blood pressure and possibly getting a cardiology clearance. I would also ensure sleep remains undisturbed and further recommend any intervention to improve sleep.”