With the number of people living with dementia expected to double to 65.7 million by 2030, any breakthrough in the Alzheimer's arena is a welcome one -- especially if it leads to a method for slowing the disease.
One such breakthrough happened this week, when researchers announced that a commonly prescribed antidepressant may be able to reduce production of the main ingredient in Alzheimer's brain plaques.
Brain plaques are closely connected to memory problems and other cognitive difficulties caused by Alzheimer's. If researchers can stop the plaque buildup, they may be able to stop the horrific mental decline caused by the disease.
Scientists found that the antidepressant citalopram stopped the growth of plaques in a mouse model of Alzheimer's. What was even better is that a single dose of the antidepressant lowered production of amyloid beta -- the primary ingredient in plaques -- by 37 percent in young healthy adults.
Even so, researchers urged caution.
"Antidepressants appear to be significantly reducing amyloid beta production, and that's exciting," said senior author Dr. John Cirrito, assistant professor of neurology at Washington University School of Medicine, in a written release. "But while antidepressants generally are well tolerated, they have risks and side effects. Until we can more definitively prove that these drugs help slow or stop Alzheimer's in humans, the risks aren't worth it. There is still much more work to do."
Amyloid beta is a protein produced by normal brain activity. When a person has Alzheimer's, levels of this protein go up in the brain, causing pieces of it to clump together to form plaques.
The researchers have studied the impact of antidepressants on Alzheimer's before. In 2011, the researchers tested several antidepressants in young mice genetically altered to develop Alzheimer's disease as they aged. In these mice, which had not yet developed brain plaques, antidepressants reduced amyloid beta production by an average of 25 percent after 24 hours.
For the new study, the team gave citalopram to older mice with brain plaques. Giving the mice the antidepressant stopped the growth of existing plaques and reduced the formation of new plaques by 78 percent.
In a second experiment, the scientists gave a single dose of citalopram to 23 people aged 18 to 50 who were not cognitively impaired or depressed. Samples of spinal fluid taken from the participants over the next 24 hours revealed a 37 percent decline in amyloid beta production.
Researchers say they next plan to study older adults who will be treated for two weeks with antidepressants to find out if the beneficial reduction in amyloid beta is sustainable.
The findings were published May 14 in Science Translational Medicine.
In other Alzheimer's-related research this year, scientists found that chronic sleep disturbances may speed up the onset of dementias. The good news is that you can improve your quality of sleep with breathing techniques and other simple moves.
And in a study from last year, scientists discovered new genes linked to late-onset Alzheimer's, giving them clues on how to create better drugs to fight the disease.