Introduction

Nightmare disorder is a rare sleep condition that involves people experiencing repetitive, distressing dreams that can impair people in both the daytime and night-time.¹ There have been many links between experiencing nightmares and having other comorbidities, including psychological disorders, physiological changes and also hyperarousal of the brain. In some cases, alcohol consumption has been found to influence both sleep patterns and the content of a person’s dreams, resulting in the worsening of or onset of nightmare disorder.

What is nightmare disorder?

According to the DSM-5 criteria (The psychiatric condition list used by the U.K.), nightmare disorder is the repeated occurrence of extended and well-remembered dreams in which a person becomes quickly alert and oriented once awoken and causes significant clinical distress.² These strange and somewhat distressing dreams can’t usually be explained by any other medical condition or specific mental illness, making the symptoms of their disorder. Mild cases typically involve having this experience more than once per week but less than nightly, whereas severe disorders involve nightly episodes.³

Often, the nightmares can be associated with sweating and sobbing during sleep as well as increased leg and eye movements without the person knowing that they are in this physical state. Among the most common emotions reported by individuals who experience this condition are fear, anger, and sadness, with many reporting that they can re-experience these emotions throughout the day when reflecting on the previous night’s sleep.¹ The most common content of these dreams are physical aggression, failure, and helplessness, which can continue to haunt the person throughout the day, causing further negative emotional episodes in the daytime.⁴ This cycle of negativity throughout the day and night results in people being unable to function appropriately.

Causes of nightmare disorder

There are many different theories surrounding the cause of nightmare disorders, some concerning adverse life events and others to brain hyperarousal.³ It has been suggested that, throughout the day, different thoughts and ideas build up in the brain, meaning that the brain has no time to shut down and relax when it reaches time to sleep. This is one of the main pathways thought to occur in other medical conditions like PTSD and insomnia.⁵ Over time can produce more broken and poor quality REM sleep than what is seen in someone without this disorder.

Other causes of nightmare disorder include adverse life events and the maladaptive behaviours that people use after experiencing these events. Major traumas related to death and injury, and other issues stemming from childhood, including abuse and neglect, can play a role in the onset of recurrent nightmares throughout childhood and adult life.6 These events can lead to people re-experiencing them throughout both the day and night, requiring them to form sometimes negative coping mechanisms to deal with these issues. Some of the negative mechanisms include suppressing unwanted thoughts and feelings associated with the nightmares throughout the day, as well as clinging to unhealthy habits like alcohol and nicotine dependency. This can further reduce the quality of sleep and intensify nightmares.

When do nightmares occur?

Humans have two types of sleep that they cycle through each night: NREM and REM sleep. NREM is further divided into 4 sleep stages that have different characteristics and lengths throughout the night, getting progressively longer throughout the stages. After these 4 stages of sleep have occurred, REM can begin, during which people often experience all of their dreams within the REM block. During NREM sleep, the four sleep stages can help to increase memory consolidation and progress from lighter to deeper sleep as the night goes on.⁷ Often associated with REM is desynchronised brain activity, muscle atony and rapid eye movements.⁸ This is the part of sleep in which nightmares and any associated thrashing or crying can occur.

Alcohol and sleep

Alcohol is a psychoactive substance that can initially cause feelings of euphoria in smaller concentrations and then progress to CNS depression and sedation when consumed in higher concentrations.⁹ In the short term, alcohol intake can help to send people off to sleep more quickly, which can be of benefit to those who struggle with initially getting to sleep. Insomnia and other sleep difficulties come into the second half of the night once the alcohol begins to wear off, meaning that it is quite common for the length of sleep to be reduced, and the overall quality of sleep is massively reduced ¹⁰

There have been multiple links between alcohol dependency and sleep/insomnia issues. Addiction to substances can often be found to co-exist with other mental health conditions, including PTSD and depression, which have links to nightmare disorder.¹¹ Often, when a person aims to reduce or completely stop their alcohol intake, they can experience sleep disturbances and sleep-associated movement disorders for months after the last drink of alcohol.¹² Nightmare disorder is associated more commonly with acute withdrawals and occurs less often after 12 months of abstinence. It should be noted, however, that it is extremely difficult to remain abstinent from alcohol when someone has struggled with addiction previously, and there is an increased risk of relapse, especially when someone suffers from nightmare disorder ^13.

Summary

Nightmare disorder is a very challenging and unsettling condition that is quite rare in the vast majority of the population, but is more common in people with co-existing mental illness, including PTSD, insomnia and alcohol dependency. It can be difficult to separate the nightmares from reality, as they can continue to haunt the person throughout the day, too. Alcohol withdrawal can also initially worsen the experience of nightmares for many individuals for a period ranging from a few months to a few years, making it more difficult to stay away from alcohol permanently. Health professionals need to take extra care when helping those who suffer from both nightmare disorder and alcohol dependency, as the normal steps of therapy and medication used in those with only one of the conditions may not be enough to tackle a more serious case concerning both disorders. Further research needs to be completed to determine how best to support those suffering concurrently with alcohol dependency and nightmares, with the hopes of reducing the time spent experiencing these vivid and sometimes traumatising nightmares.

FAQs

What are the most common symptoms when experiencing alcohol withdrawal?

People can experience a range of symptoms when withdrawing from alcohol, depending on how many hours it has been since they last drank. These can range from sweating, tremors, nausea and difficulty sleeping in mild cases and rapid heart rates, seizures and hallucinations in more severe cases.¹⁴

How can nightmare disorder be treated?

Different therapy tools can be used to help those suffering from nightmare disorder. Similarly to what is used in PTSD treatment, CBT, EMDR and exposure therapies are used to help process the emotions that are felt during the nightmares and for days afterwards. Deep muscle relaxation can also be useful for repetitive nightmares.¹⁵