Sunday, June 28, 2009
Depression Linked to Alzheimer’s Disease
Mild cognitive impairment (MCI) effects many of the elderly and is regarded as the period between the forgetfulness of normal aging and Alzheimer’s disease. Usually patients with MCI may be more forgetful than an average person but they do not show other signs of Alzheimer’s. Knowing which patients would progress from this “forgetful” stage into Alzheimer’s has long been a diagnostic problem for medical personnel. Among the problems in being able to predict who is at higher risk for Alzheimer’s has been what problems concurrent with the MCI would contribute to the increased possibility of the disease.
Researchers recently studied 756 people with MCI between the ages of 55 and 91 for three years. Approximately a quarter of the study group were diagnosed with depression. The depression test produced results in points and for every point of increase on the test the risk of developing Alzheimer’s went up by 3 percent. Assistant professor Po H. Lu of the UCLA David Geffen School of Medicine said that the results suggest depression is a major risk factor for Alzheimer’s disease.
Study participants were given donepezil (sold as Aricept), vitamin E, or a placebo. The percentage of those with depression receiving the vitamin or a placebo developed Alzheimer’s at almost double the rate of those receiving donepezil. The drug seemingly did not affect those who were not suffering from depression. “If we can delay the progression of this disease for even two years, it could significantly improve the quality of life for many people dealing with memory loss.” according to Lu.
Aricept has FDA approval for use in patients with MCI, but only those diagnosed with Alzheimer’s. Conclusive diagnoses of those who will progress to Alzheimer’s would make providing preventive treatment much more successful. It would also provide scientists a specific target for improved research and the possibility of a real cure for Alzheimer’s.
Appropriate pre-diagnoses may not be an unrealized dream for scientists much longer. Researchers at the University of California, San Diego School of Medicine have used an automated procedure called Volumetric MRI, for measuring the “memory centers” of the brain and compare them to usual size to determine if brain atrophy has occurred. Brain atrophy is a sure indicator of Alzheimer’s.
"Use of this procedure is like bringing the experience of an expert neuro-radiologist to any clinic that has the right software," said James Brewer, MD, PhD, assistant professor in UC San Diego's Departments of Radiology and Neurosciences. "These fully automated and rapid methods of measuring medial temporal lobe volumes may help clinicians predict cognitive decline in their patients, and have the potential to influence how neurology is practiced."