Could Medical Treatment Already Be Available to Slow Alzheimer's Disease
A treatment for Alzheimer's Disease is desperately needed. Currently it is estimated that 5.2 million Americans have Alzheimer’s with almost two-thirds of them women. The latest facts and figures from the Alzheimer’s Association suggests that this number will continue to rapidly rise as the “baby boom” generation ages. By 2050, the number of those affected may reach as many as 16 million.
Obviously, there is great reason for research on how to either slow down the disease process or to find a cure. Wouldn’t it be great if one way slow the progression of Alzheimer’s could be found in a drug that already exists and is approved by the FDA?
Antidepressant Therapy Could Slow Plaque Buildup
Researchers at Washington University School of Medicine in St. Louis and the University of Pennsylvania are hopeful that a commonly prescribed antidepressant can reduce production of the main ingredient found in Alzheimer’s brain plaques. These plaques are closely tied to memory problems and other cognitive impairments in Alzhiemer’s, so stopping their buildup could potentially slow mental decline.
Citalopram (brand name: Celexa) is one type of selective serotonin reuptake inhibitor, or SSRI. These drugs work by inhibiting the reuptake of serotonin in the brain, an action that allows more of the neurotransmitter to be available. Senior author John Cirrito PhD, an assistant professor of neurology, has found in previous studies that serotonin reduces amyloid beta production in mice. The team has also tested the drug in humans and found that a single dose lowers the production of amyloid beta by 37%.
Amyloid beta is a protein that is produced by normal brain activity. However, levels of this protein rise in the brains of those with Alzheimer’s disease, causing it to clump together into plaques. These plaques build up in the spaces between nerve cells and block normal communication and process the cells need to survive.
If these drugs can slow plaques from forming, can they decrease plaque buildup that has already occurred and thus be beneficial to those already diagnosed with Alzheimer’s? To test this new theory, Jin-Moo Lee MD PhD gave citalopram in older mice with brain plaques. The growth of these plaques was tracked for 28 days. The antidepressant appeared to stop the growth of existing plaques and reduced the formation of new plaques by 78%.
Of course, as usual, “don’t try this at home.”
"Antidepressants appear to be significantly reducing amyloid beta production, and that's exciting," said Dr. Cirrito. "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."
Yvette I. Sheline, John R. Cirrito, et al. An Antidepressant Decreases CSF Aβ Production in Healthy Individuals and in Transgenic AD Mice. Sci Transl Med 14 May 2014: Vol. 6, Issue 236, p. 36re4 Sci. Transl. Med. DOI: 10.1126/scitranslmed.3008169