Within the normal population 4-8% of the people suffer regularly from nightmares. Clinical observations show that nightmares are a common problem for patients who suffer from all kinds of psychiatric disorders, and not just for the patients diagnosed with PTSD. Often nightmares can lead to sleep disorders, which have a negative impact on emotional well-being and cognitive functioning during the day. As well as this a strong relationship between severity of nightmares and severity of psychopathology has been found. This gives a strong argument for treatment of nightmares as a symptom, separate from the psychiatric disorder.
A few controlled studies of the treatment of nightmares have been published, in which behavioral therapy, relaxation techniques, exposure and systematic desensitization have been studied, all of which have shown positive results. But these techniques do not seem to reduce the number of nightmares in patients who suffer from PTSD. These last few years more controlled studies of a cognitive behavioral technique called 'Imagery Rehearsal Therapy' (IRT) have been published. With IRT patients have to change the script of their nightmares into a different outcome, and rehearse this new script using cognitive imagery a few times a day.
Comparisons: treatment of nightmares with IRT compared to a waitlist control group who do not get IRT until 6 months later.