MONDAY, Jan. 14, 2013 (HealthDay News) -- Four U.S. government-funded clinical trials will search for new therapies for Alzheimer's disease.

The five-year effort will look at drug and exercise treatments for patients with early stage disease, test if the generic drug prazosin can reduce agitation in Alzheimer's patients, and examine a new approach to speed testing of drugs in clinical trials.

The trials, which could cost as much as $55 million, are projects of the Alzheimer's Disease Cooperative Study (ADCS), a consortium of academic medical centers and clinics established in 1991 by the U.S. National Institutes of Health.

The consortium, which includes more than 70 sites in the United States and Canada, focuses on research of diagnosis and treatment methods that might not be tested by the drug industry.

The four studies are among efforts to accomplish the research goals outlined in the National Plan to Address Alzheimer's Disease, which was announced in May 2012. The plan calls for a coordinated and focused effort in research, care and services for Alzheimer's and related types of dementia. The goal is to find ways to prevent and effectively treat Alzheimer's by 2025.

"The ADCS is a key initiative in the federal program to discover, develop and test new Alzheimer's treatments and diagnostic tools. Over the years, it has proved invaluable in advancing our understanding about the disease and how to conduct research in this challenging area," Dr. Richard Hodes, director of the National Institute on Aging, said in an NIH news release.

"I am particularly excited that this round of studies will use what we have learned by testing interventions pre-symptomatically, as early as we can in the development of the disease, where we now think the best hope lies for keeping Alzheimer's at bay," he added.

More information

The Alzheimer's Association has more about Alzheimer's disease.