Introduction

Definition of nightmare disorder

Nightmare disorder is a pattern of recurrent vivid and frightening dreams that cause significant distress and impaired functioning. It is also a type of behavioural sleep abnormality, known as parasomnias. Nightmare disorder usually occurs during the second half of the sleep period, mainly during the rapid eye movement (REM) sleep, and with this disorder, you will usually remember your nightmare even after being awake, which differs from sleep terrors.¹

Overview of associated sleep disorders

Nightmare disorder is associated with several different sleep disorders, like insomnia, obstructive sleep apnea and REM sleep behaviour disorder (RBD). These are disorders that are unpleasant and can cause significant distress to you, as they can start to affect your quality of life.¹

Insomnia and nightmare disorder

Definition and types of insomnia

Insomnia is a type of sleeping disorder that can affect your quality of life. It causes you to have trouble falling asleep or even staying asleep. You can wake during the night or wake up early in the morning. There are different types of insomnia, including:

• Transient insomnia: happens for less than one month
• Short-term insomnia: happens between one to six months
• Chronic insomnia: occurs for more than six months
• Comorbid insomnia: when insomnia exists in conjunction with another medical condition
• Primary insomnia: insomnia that exists without any other medical condition^2,3

Relationship between insomnia and nightmares

Insomnia means trouble falling or staying asleep, this can lead to poor-quality sleep, which makes it harder to manage emotions and then increases sensitivity to threats. This heightened sense of threat, especially before bed, along with negative thoughts and feelings, can trigger nightmares.

Nightmares, in turn, can worsen sleep problems by causing fear of sleeping, avoiding going to bed, and frequent awakenings during the night, which then also leads to sleep loss. Nightmares also leave lingering negative feelings the next day, changing your mood and stress levels, affecting your mental health.

Underlying all of this are deeper factors, including past trauma, stress and personality traits, such as neuroticism. These can contribute to both insomnia and nightmares, creating a cycle that is hard to break.⁴

Treatment

There are various ways you can treat insomnia-related nightmare disorder, including:

Cognitive-behavioural therapy for insomnia

This is a type of therapy used for insomnia, helping with improving your sleeping patterns until you have a better sleep quality. It involves learning good sleep hygiene by getting rid of distractions and keeping a consistent sleep schedule. Mainly focusing on changing your thoughts and behaviours, and creating a sleep schedule that gradually improves your sleep.⁵

Changing your lifestyle

Avoiding big meals and alcohol, staying active and doing relaxation exercises are advised.

Obstructive sleep apnea (OSA) and nightmare disorder

Definition and pathophysiology of OSA

OSA is a condition that affects the way you breathe during sleep. There is a blockage or narrowing in the airway that keeps the air from moving through your windpipe when you are asleep. The blockage and the lack of airflow cause the blood oxygen levels to drop, triggering the survival reflex in your brain that wakes you up just enough for you to breathe again. This reflex is important, but it can also disrupt your sleep.⁶

Connection between OSA and nightmare frequency

OSA can be associated with an increase in the frequency of nightmares, though this is still complex and is yet to be understood by researchers. Some studies suggest that patients with more severe OSA, more specifically having a higher Apnea-Hypopnea Index (AHI), report a lower nightmare frequency. This can be because OSA disrupts REM sleep. This is still a theory that is yet to be understood and researched.⁷

Clinical presentation

Like nightmare disorders, some of the signs you may experience similarly are:

• Fatigue
• Sleepness
• Depression and anxiety
• Headaches
• Continued disrupted sleep⁶ 

Diagnosis and treatment considerations

How is OSA diagnosed?

There are two tests that your doctor may do to diagnose you with OSA, including:

• Polysomnogram: an overnight sleep study, you will sleep in a medical facility where your sleep is monitored by doctors
• Home sleep apnea test: similar to a polysomnogram, but it does not involve brain wave monitoring⁶

How is it treated?

• Using continuous positive airway pressure (CPAP) machine: keep your airways open whilst you are sleeping
• Making lifestyle changes
• Using mouthpieces
• Surgery: in more severe cases 

REM sleep behaviour disorder (RBD) and nightmare disorder

Definition and features of RBD

RBD is a parasomnia, meaning is a sleep disorder that involves unusual and undesirable physical events or experiences that can disrupt your sleep. In RBD, you physically and or vocally act out your dreams while in the REM stage of sleep. You are unaware of your actions while you are sleeping.⁸

Distinguishing RBD from nightmare disorder

Though these are very alike, some key differences can distinguish a RBD from a nightmare disorder, including:⁹

Motor activity 

In RBD, there is more motor activity during REM sleep, so normally, there is more muscle atonia that prevents movement during sleep. However, in nightmare disorder, it causes fear and anxiety, and it does not involve any kind of movement during sleeping.

Dream enactment

In RBD, most people act out their dreams, often with motor activity, such as punching, kicking and talking whilst sleeping and without realising. In nightmare disorder, however, most experience nightmares and being awake from the nightmare, feeling very scared and anxious.

Treatment approaches

There are various medical approaches you can take to treat RBD, including:

• Melatonin: a hormone that your pineal gland naturally secretes to help regulate your sleep cycle used as the main medication for treating RBD
• Clonazepam: it is a sedative and it is not fully understood why it helps in treating RBD, but people have experienced few or nightmares, talking or dream acting behaviours⁸

Summary

Sleep is something that people always take for granted until they are not getting enough of it. Sleep is critical for our well-being and for our health, and the lack of it can cause disruptions to our overall health. If you are having trouble sleeping, it is a good idea to talk with your doctor, as they can help you improve your sleep or refer you to a professional who can assist you in improving your sleep.