What is nightmare disorder?

You might think, “Oh, just another bad dream?” But no- this is more than that. These are vivid, frightening, and repetitive nightmares that constantly disrupt your sleep, often causing you to wake up suddenly or in fear. It’s not occasional; it happens regularly, sometimes every night, and you clearly remember what happened in them.If this is something you experience, you may have a Nightmare disorder.

Nightmare disorder is a mental health disorder characterised by long and extremely dysphoric dreams occurring during REM sleep that often involve attempting to avoid dangers to one's physical integrity, security, or ability to survive.¹ It is diagnosed clinically according to DSM-5 and ICSD-3 criteria. Individuals suffering from this often have a fear of falling asleep due to the anxiety of having nightmares, sweating, emotional disturbances and mood disturbances. The disorder is known to coexist with other comorbidities like anxiety, depression, and other psychopathological disorders.² In patients suffering from psychiatric problems and post-traumatic stress disorder (PTSD), the occurrence of nightmare disorder is even more common. So much so that about 19 to 71% of those with the disease experience nightmares.³

Despite how common nightmare disorders are, the screenings and treatments of chronic nightmare disorders are rare, even in sleep centres.¹ Treatments are effective in only one session and other non-clinical means; however, the majority of people who experience nightmares do not seek the assistance of a specialist.⁴

A significant number of patients prefer to continue living with their nightmares because they are unaware of any other available choices.

This is why understanding the brain science behind this disorder is so important- knowing why and how it occurs, what research and medicine have uncovered, and what treatment options are available for those who experience it.

How do dreams and nightmares occur?

Did you know that doing nothing does not mean your brain is inactive? Your brain is always active, and good examples of this are dreams and nightmares. When you are asleep (REM and NREM), your brain is just as active as when you are awake, but the senses that recognise external stimuli are turned down. Therefore, as the brain remains active, the stimulation of different cortical and subcortical areas triggered by arousal such as waking thoughts results in patterns of activity that give rise to dreams.⁵

Dreams are formed by a complex interplay and activation of neurons between the brainstem and forebrain (limbic, temporal, and occipital regions). They mostly occur during REM sleep, especially vivid dreaming. This is because of the electrophysiological associations of neurons of the medulla, pons, amygdala, and hippocampus that play a role in putting together memories, making them stronger and emotions are selectively active during this type of sleep.⁶ This also implies that the brain regions responsible for generating images are activated, which explains the vivid visuals experienced during dreams, even in the absence of actual visual stimuli.

An analysis of dream content revealed that dreams are not merely replays of past thoughts, but also carry a profound emotional significance.⁷ This explains why many dreams you will often have reflect the emotions you felt during the day.

Nightmares occur during REM sleep due to disruptions in emotional regulation within key areas of the brain, such as the hippocampus and anterior cingulate cortex, which are responsible for processing emotions. This imbalance can amplify real-life feelings- most commonly fear, but also anger, sadness, embarrassment, or guilt- leading to a deeply unsettling and often distressing experience.⁷

What brain regions are involved in nightmare disorder?

A lot of cortical and sub-cortical areas are involved in the formation of nightmares in nightmare disorder, the most important are:^{6, 8, 9}

• Amygdala – activated during REM sleep, contributing to the emotional intensity of nightmares
• Dorsolateral prefrontal cortex – deactivated during REM sleep, leading to illogical dream content
• Hippocampus – involved in memory replay (especially traumatic memories)
• Insula
• Anterior cingulate cortex controls the feeling of fear; it can be inhibited in nightmares, leading to exaggerated experiences
• Ventromedial prefrontal cortex (vmPFC) - impaired regulation leads to nightmares, involved in emotional processing
• Pontine brainstem - regulates REM sleep and pontine waves. It plays a role in what makes you remember nightmares so vividly
  

What neurotransmitters are involved in making a nightmare occur?

Neurotransmitters are chemical messengers in the body. I. They are essential to help initiate different actions and responses in your body by transmitting signals through neurons. There are specific neurotransmitters that are involved in the nightmare process. Some of the important ones are:^9,10

• Norepinephrine– increased emotional memory and stress responses are linked to abnormal norepinephrine activity. Both of these things can make nightmares worse, especially nightmares related to PTSD
• Serotonin- regulates mood and controls REM sleep; lower amounts of serotonin can make it harder to stay in REM sleep and make nightmares more likely.
• Dopamine– dysregulation may cause more detailed and highly charged dreams, some of which can be nightmares 
• Acetylcholine– increased activity of acetylcholine during REM sleep can intensify the emotional aspects of dreams, which may cause nightmares
• GABA– GABA disruptions can mess up sleep and REM control, which could lead to trouble sleeping and nightmares
• Glutamate- the hyperactivity of glutamate signalling may make emotional memories too active, especially in people with PTSD, which may help explain why some people have dreams over and over again
  

What neurobiological theories explain why nightmares happen?

Have you heard the saying by Freud, “Dreams offer a portal of knowledge to the unconscious mind?” This set the tone for the theories that explained why nightmares occur. 

There are mainly two reasons:^11,12

Hyperarousal: The state of alertness and anxiety that builds up during the day and stays high at night may play a role in the development of nightmare disorder. This raised alertness speeds the processing of information and beta activity while sleeping. In the same way that hyperarousal is common in PTSD and sleeplessness, it may also help explain how nightmares start

Impaired fear extinction: Normal sleep and dreams can help get rid of fear by putting together scary memories with new, separate situations. But people with nightmare disorder keep activating disturbing memory pieces while they sleep, which reinforces their fearful memories. This happens because the amygdala is overactive, and there is a distortion of the frontal lobe regulatory pathways of the brain, like the medial prefrontal cortex

The factors that enhance or facilitate hyperarousal and impairment of fear extinction are: traumatic experiences, maladaptive beliefs, childhood abuse or neglect, stress, anxiety, trying to suppress negative thoughts, and some drugs that influence the neurotransmitters involved in regulating dreams, among others, see above.

Treatment based on brain science

Treatment of nightmare disorder is individualised. The physician will give you a treatment plan based on your symptoms that mainly targets the root cause of the triggers. 

Some of the known treatment options include:

Interventions in psychotherapy

In imagery rehearsal therapy (IRT), patients rewrite their dreams while they are awake and practise the new version. Studies show that it makes nightmares and PTSD signs a lot less common.

Desensitisation and Exposure Therapy: helps people deal with their nightmares by slowly and gradually exposing them to things that scare them.

The goal of lucid dreaming techniques is to make people more aware during their dreams so that they can control the story of their nightmares.

Medicines used for treatment

Prazosin, an alpha-1 adrenoreceptor antagonist, has been shown to help people with PTSD who have dreams. Other Drugs, such as o antidepressants and antipsychotics, may also be considered, but the evidence pertaining to their use is weak. 

Self-Help and Interventions 

Programs on the Internet: Online therapy is just as effective as physical therapy.

Self-help Materials: Books and tasks with answers can be helpful, especially when you can't get professional help.

FAQs 

Are night terrors and nightmares the same?

In contrast to night terrors, which cause confused awakenings, incomplete awakenings, and trouble being soothed, people with nightmare disorder wake up fully, can adjust themselves right away, and remember the dream clearly.

Summary 

Nightmare disorder is a very serious condition that can be debilitating. It has to do with altered brain chemistry in different parts of the brain. Many things can influence one developing nightmare disorder, but the most common is traumatic events that can cause PTSD, chronic stress and anxiety or a history of early childhood abuse or neglect. There are many treatment options available that work; however, many people do not get help. 

More awareness and research on the disorder are encouraged.