Consequently, assessment of nightmare disorders using polysomnography has to last for a longer period, in order to let the patient getting used to the artificial environment.Self-report by a questionnaire or by a diary is another way to investigate nightmare disorders. However, these methods are questionable. Indeed, when filling out questionnaires with questions about a long period, people often tend to underestimate the frequency of their nightmares because of forgetting. On the contrary, filling out a diary every day may lead to an overestimation of the numbers of nightmares, because of the focusing on this phenomenon. Comorbidity
Studies have reported that nightmare disorders were present in 50- 70% of the cases for PTSD, in 17.5% for depression, in 18.3% for insomnia, in 16.7% for schizophrenia and in 49% for borderline personality disorder. For all psychiatric disorders taken together, nightmare disorders are present in 29.9% of the cases, a much bigger rate than for the general population, which is 2-5%. Nightmare disorders can also be associated with sleep disorders such as night terrors, chronic insomnia and sleep-disordered breathing. The presence of nightmares before a trauma would influence severity of PTSD symptoms. Furthermore, having nightmares is linked to a significantly higher risk of attempting suicide and of death by suicide. Treatment
Stress reduction techniques such as yoga, meditation and exercise may help to eliminate stress and create a more peaceful sleeping atmosphere.Diagnosis and medication can only be given to patients that report the recurring nightmares to a psychiatrist or other physician.
Blood pressure medication, levodopa and medications for Parkinsons disease have also been known to cause nightmares.The nightmares may be idiopathic or could be associated with psychiatric disorders like post-traumatic stress disorder, schizophrenia, and borderline personality disorder. Nightmares can also be triggered by stress and anxiety and substance abuse, such as drugs that affect the neurotransmitters norepinephrine and dopamine and serotonin. Nevertheless, causality between drugs such as beta-blockers or alpha-agonists and nightmares is still unclear and further research needs to be done to investigate the biochemical mechanisms of nightmares.Eighty percent of patients who have PTSD report nightmares. Patients with PTSD have symptoms that are classified into three clusters: intrusive/re-experiencing, numbing, and hyperarousal. Nightmares are usually considered to be part of the intrusive/re-experiencing symptom.Some differences are existing between idiopathic and PTSD related nightmares. A PTSD person having nightmares would wake up during the night more frequently and for a longer time than with idiopathic nightmares. Consequently, people with PTSD would have a poorer sleep quality. Furthermore, nightmares related to PTSD would be more stressful than idiopathic ones. However, further studies have to be conducted in this area to obtain more reliable results. Assessment
Polysomnography records physiological parameters, such as electroencephalography (EEG), electromyography (EMG) and electrooculography (EOG) in a sleep laboratory. However, the frequency of posttraumatic nightmares tends to decrease in an artificial lab setting, which would impact the content of nightmares.