Nightmares and nightmare disorder

Nightmares mostly occur during REM (rapid eye movement) sleep, the stage when dreaming is most vivid. Because REM periods get longer toward morning, nightmares often happen in the second half of the night. People typically wake up fully, remember the content and may find it hard to fall back asleep.

Common nightmare themes include being chased, falling, being attacked, losing loved ones, failing or being trapped. The emotions are usually fear, but they can also include anger, sadness, guilt or disgust.

Bad dreams are common in children and become less frequent with age, though many adults have them from time to time. Nightmare disorder is diagnosed when nightmares are repeated, cause significant distress, and interfere with sleep, mood, concentration or daily life. Recurring nightmares, with the same or similar content, are especially common after trauma.

Nightmares and night terrors are often confused, but they're quite different:

Nightmares:
- Happen during REM sleep, usually later in the night
- The person wakes up and is quickly alert
- The dream is usually remembered in detail
- More common in adults and older children

Night terrors (sleep terrors):
- Happen during deep non-REM sleep, usually in the first part of the night
- The person may scream, thrash or sit up looking terrified, but isn't fully awake
- They're hard to comfort and usually don't remember the episode the next day
- Most common in young children, and many outgrow them

Both can be distressing for the person and those around them. Night terrors in adults, or any episodes involving injury or dangerous behaviors during sleep, should be evaluated by a doctor or a sleep specialist.

Many factors can trigger or increase nightmares:

• Stress and anxiety, including major life changes or ongoing worries
• Trauma: nightmares are one of the core symptoms of PTSD, and PTSD nightmares often replay or echo the traumatic event
• Depression and other mental health conditions
• Sleep deprivation or irregular sleep schedules
• Certain medications, or stopping some medications
• Alcohol, especially withdrawal or heavy use, and some recreational drugs
• Other sleep disorders, such as sleep apnea
• Watching frightening content close to bedtime

Sometimes there's no obvious cause. Nightmares can also become self-perpetuating: fear of having another nightmare leads to anxiety around bedtime, poorer sleep and, in turn, more nightmares. Understanding this cycle is part of breaking it.

Frequent or distressing nightmares respond well to treatment.

• Imagery rehearsal therapy (IRT): one of the best-supported treatments. While awake, you write down a recurring nightmare, change the storyline in any way you choose, and rehearse the new version in your mind daily. Over time, this can reduce how often nightmares happen and how intense they are.
• Cognitive behavioral therapy for insomnia (CBT-I): helps improve overall sleep, which can reduce nightmares.
• Trauma-focused therapies: for PTSD nightmares, treating the underlying trauma with approaches such as trauma-focused CBT, cognitive processing therapy or EMDR often reduces nightmares.
• Relaxation and stress management techniques.

A psychiatrist or physician may consider medication in some cases, particularly for trauma-related nightmares. It's also important to review any medications you take that might contribute.

A psychologist, clinical psychologist or a sleep specialist can help. In the first appointment, expect questions about your sleep, the content and frequency of nightmares, stress, trauma history and health.

Some simple habits may help reduce bad dreams:

• Keep a regular sleep and wake time.
• Create a calming bedtime routine, such as reading or gentle stretching.
• Avoid alcohol, heavy meals and stimulating content in the hour or two before bed.
• Write down worries earlier in the evening so they don't follow you to bed.
• If you wake from a nightmare, ground yourself: turn on a soft light, notice your surroundings, breathe slowly and remind yourself it was a dream.
• Keep a sleep diary to spot patterns or triggers.

For children, calm reassurance, a predictable routine and limiting scary media are usually most helpful.

Talk to a professional if nightmares happen often, if you're afraid to go to sleep, or if they're linked to a traumatic experience. If nightmares come with thoughts of self-harm, seek help right away: in the US, call or text 988; in the UK and Ireland, call Samaritans at 116 123.