Today we're going to talk some more about nightmares, particularly Night Terrors and REM Behavior Disorder.
Nightmares are common in patients with psychiatric disorders, but in general, nightmares can simply be caused by stressful or traumatic experiences. There is a common myth that frequent nightmares, especially in children, are a marker of psychiatric disease. This is not the case. However, frequent nightmares have been described in "right-brain-types" who demonstrate "thin boundaries" on psychological testing. (For more on this, read Ernest Hartmann's "The Nightmare: The Psychology and Biology of Terrifying Dreams").
Nightmares should be differentiated from night terrors, also known as sleep terrors. Night terrors are episodes of extreme panic or fear that usually occur earlier in the night, as opposed to nightmares which tend to occur later in the night. They are actually related to other sleep disorders such as sleepwalking and do not occur during REM sleep, but during deep sleep or delta sleep.
Most parents can recall nights when their child would wake up with blood-curdling screams, would appear confused and sweaty and were totally inconsolable. These episodes usually occur during increasingly active times when the child might not be getting enough sleep. Often times the child would look at you as though they weren't aware that you were there. That's because they weren't.
When night terrors occur the sufferer is still in a sleep state. These episodes usually just end with the child falling back asleep and not being able to recall what happened in the morning.
These events are common in children and usually go away with age. As opposed to those with frequent nightmares, those with frequent night terrors may have a psychiatric disease if the terrors persist into their adult years.
There is a fascinating sleep disorder associated with nightmares called REM behavior disorder (RBD). Normally, during REM sleep (the sleep stage where we do most of our dreaming), our bodies are essentially paralyzed making it impossible to act out our dreams. In RBD the paralysis is lost and muscles are able to work. This results in situations where a sleeping man can be dreaming that he is involved in a violent battle against an intruder and wake up only to discover that he is attacking his wife. The dreams in RBD often tend to be vivid, action-filled, and violent dreams that the dreamer acts out, causing injury to the dreamer or the sleeping partner. This disorder is most common in middle-aged men and has been associated with later development of other neurological diseases, particularly Parkinson 's disease.
Obviously, in RBD the patient and sleeping partner need to take common-sense precautions to avoid injury, such as sleeping separately and making sure not to keep potentially harmful objects in the bedroom. Usually after a sleep study that documents some muscular activity in during REM sleep, a patient can be started on a sedative called Clonazepam that usually works very well to control the behaviors.