Nightmares are elaborate and frightening dreams that can lead to high levels of anxiety and terror. In most cases, a person dreams about coming to some sort of harm that may involve being chased, injured or threatened in some way. Some psychiatric conditions are associated with recurrent nightmares, particularly post-traumatic stress disorder.
Occurrence of nightmares
The frequency of nightmares varies from person to person. Some individuals experience nightmares only rarely, while others find nightmares disrupt their sleep every night. For some individuals, the same recurring nightmare may repeatedly wake them up in a state of terror. The theme of nightmares may also vary considerably but will induce anxiety and fear one way or another.
Remembering a nightmare
Unlike most dreams, which tend to be forgotten once a person awakes, nightmares can usually be remembered in detail. Typically, a person is anxious, frightened, and restless on waking up from a nightmare and has a clear recollection of the nightmare.
Phase of sleep and nightmares
Each of the sleep cycles is divided into two major parts. The majority of sleep is deep dreamless sleep called non-rapid eye movement (NREM) sleep. The other phase of sleep is the rapid eye movement (REM) sleep. Nightmares occur almost exclusively during REM sleep. In the second half of the night, the REM phase lengthens and dreaming becomes more intense and nightmares are more likely to occur.
Who is affected?
Nightmares are first experienced very early on in life between 3 and 6 years of age, and around 10% to 50% of children aged between 3 and 5 years have nightmares severe enough to cause concern to their parents. However, most children do grow out of having nightmares.
Approximately half of the adult population report having at least the occasional nightmare and recurring nightmares affect around 7% to 8% of adults. Women report nightmares more frequently than men, with women reporting two to four nightmares for each one nightmare reported by a man. Experts are unclear on whether women are more prone to nightmares than men or simply more likely to report them.
Post traumatic stress disorder and nightmares
Nightmares are a key symptom in post-traumatic stress disorder, where a traumatic event that has caused the disorder in the first place is somehow relived in the nightmare.
If left untreated, nightmares occurring in the long term may cause severe lack of sleep and other mental health problems. Those suffering from nightmares regularly for more than 3 months need to seek help to prevent long-term consequences.
Treatment of nightmares
Nightmares can be treated with psychological therapy as well as with the use of medication. Psychological treatments have been successfully tried in people with post-traumatic stress disorder who suffer from nightmares. Cognitive behavioral therapy can also benefit these patients and reduce the amount of sleep that is disrupted. The therapy involves patients choosing a recent nightmare and imagining an alternative scenario to the frightening one. Patients then spend a few minutes each day painting a mental picture of the new scenario.
Examples of medications used to treat post-traumatic stress disorder that have reduced nightmares include topiramate, prazosin, nefazodone, trazodone, and gabapentin.
Reviewed by Sally Robertson, BSc