Although prescription medications can't stop the memory loss associated with Alzheimer's disease, a new study suggests that certain drugs can help ease another troublesome symptom of the condition – apathy.
Long before memory loss becomes a serious problem, up to 70 per cent of Alzheimer's patients can sink into a state of detachment that greatly reduces their quality of life.
"They don't interact with their caregivers or the world around them, even though they still have the cognitive ability to do that," explained Krista Lanctôt, a senior scientist at Sunnybrook Research Institute in Toronto. "They can also have emotional blunting. They don't help with their own care and don't express emotions any more. So apathy is a big problem for the patients and it can be devastating for the caregivers."
Their lack of interest is often considered a sign of depression. But Lanctôt noted that apathy should not be mistaken for blues. It is a distinct symptom likely caused by changes in the brain brought about by Alzheimer's disease.
Previous studies by Lanctôt and others, using high-tech scans, have found reduced activity in the part of the brain responsible for a sense of reward – the dopaminergic reward system – which is regulated by a chemical messenger called dopamine.
This region of the brain is also linked to apathy. So Lanctôt and her research colleagues embarked on a study to see if increasing dopamine levels could reduce apathy.
A total of 60 patients, with mild to moderate Alzheimer's, were recruited at medical centres in Canada and the United States. (Nineteen were from Toronto.) All the participants suffered from apathy. Half the patients were treated with methylphenidate (known by the brand-name of Ritalin), which helps release dopamine in the brain. The others were given a placebo.
After six weeks of treatment, there was a noticeable difference in the two groups, according to the findings published in The Journal of Clinical Psychiatry. About 21 per cent of the patients who got the drug showed an improvement in their symptoms, compared to only 3 per cent of those in the placebo group.
"This study provides the first evidence in a randomized controlled trial that these medications are actually going to be helpful for a subgroup of patients who have apathy," said Lanctôt, who is also a professor of psychiatry and pharmacology at the University of Toronto. "And, of course, Ritalin is the drug used to treat ADHD – attention deficit hyperactivity disorder. So is it involved in attention and cognition. And we think that by helping both attention and reward, we can keep people interested in their environment."
In fact, the study showed that patients treated with methylphenidate also experience some improvements in "global cognition" which includes attention, memory, language, learning, reasoning, problem-solving and decision-making.
The researchers hope drug therapy could be used to maximize quality of life for a longer period of time. "Apathy … has been shown to worsen their ability to carry out activities of daily living and it is often a key contributing factor to being institutionalized," Lanctôt, said in a statement released with the study. "If we can treat apathy, then we may be able to improve quality of life, even if we cannot really change the course of the illness."
The research was funded by a $2.5-million grant from the U.S. National Institute on Aging. In addition to Sunnybrook, other institutions involved in the study included Johns Hopkins School of Medicine and Johns Hopkins Bloomberg School of Public Health in Baltimore, Md., Medical University of South Carolina in Charleston, and the Ralph H. Johnson VA Medical Center, also in Charleston.