 From VOA Learning English, this is the health report. You wake up early one morning to prepare a meal to take to work and then you forget it. Has this ever happened to you? Researchers say they now have proof that self-reported minor memory loss sometimes led to greater mental decline six years later. They reported the findings at a recent conference organized by the Alzheimer's Association. Rebecca Amarilio is a neuropsychologist at Brigham and Women's Hospital in Boston, Massachusetts. She found that individuals who worried about their memory were more likely to suffer a loss of mental ability. Her research showed such persons were likely to have a protein called beta amyloid in the brain. Beta amyloid is suspected of being at least partly involved in Alzheimer's disease. Evidence that the disease develops for an unknown period of time before doctors recognize it is leading to a new area of study. It is called subjective cognitive decline. It involves people who sense that their memory and thinking skills are failing before others realize it. Experts want to inform the public that most people who worry about their mental decline do not develop dementia, the most common form of Alzheimer's. What they are experiencing is truly natural and normal aging. Dr. Ronald Peterson is a member of the Alzheimer's Association National Board. He says people should be tested if they fear they might have the disease. He says doctors might ask patients about other issues like any medicines they are taking or whether they suffer from anxiety, depression or stress. He says all those things can cause changes in memory. For VOA Learning English, I'm Alex Villareal.