Nightmare Disorder

What it is

A nightmare is a vivid, disturbing dream, usually involving fear, threat or distress, that occurs during the dreaming stage of sleep (REM sleep) and wakes the person, who then remembers it clearly. Nightmare disorder is diagnosed when these frightening dreams happen often enough to cause real distress, disrupt sleep, or impair daytime functioning, sometimes to the point where the person dreads going to sleep at all.

The clear memory and full waking distinguish nightmares from sleep terrors, which arise from deep non-REM sleep, leave no memory, and do not involve true waking. Because nightmares come from dreaming sleep, which is concentrated in the second half of the night, they tend to happen later than sleep terrors do.

What it can feel like

Waking in the small hours with the heart pounding, the dream still vivid and frightening, and sleep then hard to recover. When nightmares recur, a second problem grows on top of the first: fear of sleep itself. People begin to dread bedtime, delay it, and lose sleep to avoidance, which worsens mood, concentration and resilience by day. For trauma survivors, nightmares often replay or echo the traumatic event, so each night can feel like reliving it, which is exhausting and demoralising.

How common is it

Occasional nightmares are universal, and frequent nightmares are common in childhood, usually fading with age. Nightmare disorder, where they are frequent and impairing, affects a smaller share of adults. It is far more common in people who have experienced trauma; recurrent nightmares are one of the core features of post-traumatic stress disorder, and they are also associated with anxiety, depression and certain medicines.

What causes it

Nightmares can be triggered by stress and anxiety, by trauma, by some medicines and by substance withdrawal, including alcohol. In post-traumatic stress disorder, nightmares are part of how the mind keeps returning to the unprocessed event. A genetic tendency, a vivid imagination, and disrupted or insufficient sleep can all play a part. In children, nightmares often reflect ordinary developmental fears and stresses and are not usually a sign of anything wrong.

How it is diagnosed

Diagnosis is clinical, based on the description of recurrent frightening dreams with full waking and clear recall, and their impact on sleep and daytime life. The clinician asks about trauma, mood, anxiety, medicines and substances, since these point to causes that change the treatment. A sleep study is not usually needed unless another sleep disorder is suspected. Where nightmares sit within post-traumatic stress disorder, the wider condition is assessed too (see our PTSD entry).

How it is treated

Nightmare disorder responds well to focused psychological treatment. The best-evidenced approach is imagery rehearsal therapy, in which the person, while awake, rewrites the recurring nightmare with a new, non-threatening ending and mentally rehearses the new version, which over time reduces the frequency and intensity of the nightmares. Broader cognitive behavioural techniques for sleep and anxiety help as well. Treating any underlying condition is central: where nightmares are part of post-traumatic stress disorder, trauma-focused therapy addresses both. Good sleep habits, reducing alcohol, and reviewing any medicines that may provoke nightmares all support recovery. In some trauma-related cases a specialist may consider medication, but the talking therapies lead.

Nightmares in the African context

Frequent, distressing nightmares are common here, particularly after trauma, which is widespread in the region, road crashes, violence, loss, and difficult experiences, so persistent nightmares can be a signal of post-traumatic stress that deserves attention. In children, nightmares are often dismissed or, where they are read as spiritual attacks or omens, met with fear rather than comfort. The reassuring and practical message is that nightmare disorder is treatable, that a calm and comforting response helps children most, and that effective therapies exist for adults, including for trauma-related nightmares. See also our PTSD guide.

Helping someone

Whether the sufferer is a child or an adult, your response matters.

• For a frightened child, stay calm and comforting, offer reassurance and a sense of safety, and keep a soothing bedtime routine.
• Try not to dismiss or dramatise the fear, both of which unsettle a child further.
• For adults, recognise that frequent nightmares can be part of trauma, and gently encourage help, since effective treatments exist.
• Support good sleep habits, and reduce alcohol and frightening media before bed.
• Encourage professional help where nightmares are frequent or distressing. Our find a therapist page can help.