DENVER, June 22 (UPI) -- Sleep is being studied by University of Rochester researchers as a potential treatment for major depression.A study presented Tuesday at the 19th Annual Meeting of the Associated Professional Sleep Societies in Denver found depressed patients with insomnia were nearly 11 times more likely to still be depressed at six months than those sleeping well, and 17 times more likely to remain ill after a year.The study is the first to establish that insomnia prolongs bouts of sadness, hopelessness and loss of interest in life activities that characterize major depression, making patients less likely to recover.