Dear Ann Landers,
We read your column about "Dudley," the young man who became violent when he slept and hit his girlfriend. She was concerned that he harbored some kind of secret hostility toward her. You said as long as Dudley didn't hit her while he was awake, he meant no harm. Dudley may have a sleep disorder known as REM Sleep Behavior Disorder (RSBD). Normally during dream sleep, we are unable to move the muscles of the arms and legs. With RSBD, the inhibition of muscle movement is impaired, and the person may actually act out parts of his or her dreams, unaware of the behavior until some injury occurs. The good news is that sleep disorders such as RSBD can be diagnosed and treated successfully. People who suffer from insomnia, excessive daytime sleepiness or frequent leg movements before and during sleep, or who fall asleep at work, at the movies or when driving, should not hesitate to speak to their primary-care doctors about these sleep and alertness problems. For the names and addresses of accredited sleep centers, your readers can send a large, stamped, self-addressed envelope to the American Sleep Disorders Association, 6301 Bandel Rd., Suite 101, Rochester, Minn. 55901 (www.asda.org). -- Lauren Broch, Ph.D., director of education and training, and Margaret Moline, M.D., director, New York Presbyterian Hospital's Sleep-Wake Disorders Center

Dear Dr. Broch and Dr. Moline,
Thank you for providing an authoritative explanation for Dudley's behavior. You have made it quite clear that his sleep problems are not connected to his feelings for his girlfriend -- which will no doubt come as a great relief to her. Let's hope Dudley gets the help he needs so she can get a good night's sleep. Gem of the Day: To fail to forgive is to destroy the bridge over which one day you may want to travel.