Inherited forms of Alzheimer’s disease may be detectable up to two decades before problems with memory and thinking develop, according to new research.The findings are significant because by the time dementia symptoms appear, the disease has severely damaged the brain, making it nearly impossible to restore a patient’s mental abilities or memories, the study authors noted. “We want to prevent damage and loss of brain cells by intervening early in the disease process -- even before outward symptoms are evident, because by then it may be too late,” Dr. Randall Bateman, Alzheimer’s researcher and physician at the Washington University School of Medicine in St. Louis and an associate director of the Dominantly Inherited Alzheimer’s Network (DIAN), an international study of inherited forms of Alzheimer’s, said in a university news release.