The relationship between trauma and nightmares

By: Nicole Carmona, PhD, CPsych (Supervised Practice)

This blog post was adapted from an interview between Dr. Yishan Xu, Dr. Alaina Tiani, and Dr. Courtney Worley. Dr. Worley is the author of a new self-help workbook for nightmares, called The Nightmare and Sleep Disorder Toolkit: A Workbook to Help You Get Some Rest Using Imagery Rehearsal Therapy and Other Evidence-Based Approaches. Click here to watch the full interview.

Introduction

Nearly everyone can recall experiencing a nightmare at some point in their lives, and for many, nightmares are not a major cause for concern. However, for a small but significant percentage of the population, nightmares can become frequent and a source of distress and disruption during the daytime. In this article, we will discuss what nightmares are and why they happen, when nightmares are more likely to occur, and what you can do about them if you are concerned about the frequency and severity of your nightmares.

What are nightmares?

Different people might use the term “nightmare” to refer to several different nighttime experiences, so it is helpful to first define what nightmares really are, and how they differ from other types of dreams.

Dreams, including nightmares, are a normal part of sleep. They occur during a stage of sleep called rapid eye movement (REM) sleep, which mostly happens in the second half of the night. The brain is hard at work producing dreams throughout REM sleep, even though most people do not remember the majority of their dreams in the morning.

In contrast to regular dreams, a nightmare is a dream with distressing content that results in an awakening out of sleep and is remembered on awakening. The negative emotion associated with the nightmare often persists into wakefulness, making it more likely that the nightmare will be remembered and harder to return to sleep.

As stated above, while most everyone will experience a nightmare from time-to-time and perhaps shrug off the experience, for some people nightmares can become problematic. Nightmares are considered problematic when they are frequent (e.g., occurring multiple times a week or month) and intense, regularly disrupt sleep by causing multiple awakenings, and lead to feelings of distress or impairment during the daytime, such as fatigue, sleepiness, or emotional changes (e.g., increases in irritability, anxiety, or fear).

Problematic nightmares can be classified even further based on whether they are connected to a real-life event or not. Idiopathic nightmares are nightmares that have no obvious cause, whereas trauma-related nightmares occur following a real-life traumatic experience.

Who experiences problematic nightmares?

Problematic nightmares can be experienced by anyone but may be more likely if you have a diagnosis of another mental health condition. Although nightmares are most commonly thought of as a symptom of posttraumatic stress disorder (PTSD), nightmares can actually occur in the context of several anxiety, depressive, personality, and psychotic disorders. Individuals who have experienced a traumatic event but do not go on to develop PTSD can also experience trauma-related nightmares.

Even though nightmares may present as a symptom of another disorder or condition, they can over time become a problem in their own right and persistent even after successful treatment of the comorbid condition. Thus, no matter the context or comorbidity, if nightmares are frequent, intense, distressing and disruptive, they warrant their own treatment.

Why do nightmares happen? 

There is no consensus on why nightmares happen, but evidence from the fields of neuroscience and psychology have helped shape our understanding of why we experience nightmares. The stage of sleep in which nightmares occur, REM sleep, is when the brain processes emotional memories. This function of REM sleep makes nightmares more likely, whether through the processing of a memory of a real-life event, or just the processing of an emotion experienced during the daytime. In addition, during REM sleep, the regions of the brain that govern logical thinking are inactive, whereas the emotional and visual centers of the brain are highly active. This can result in vivid and emotionally distressing nightmare content that goes unchecked by the brain regions that moderate our emotional reactions.  

The mood matching hypothesis suggests that one’s dreams (or nightmares) reflect the emotions that that person experiences during their waking hours. According to this theory, because we bring our daytime emotions with us to bed, during REM sleep our brains produce visual imagery that matches those emotions. When nightmares are connected to a real-life experience, such as in trauma-related nightmares, the brain may replay some or all of the content of the traumatic experience in an attempt to try to make sense of it and integrate it into long-term memory. Sometimes these nightmares feel like a play-by-play of the traumatic experience, and other times the nightmares may reflect a theme or incorporate certain elements of the traumatic event without being an exact replay.

Unfortunately, nightmares can become recurrent through a vicious cycle. The brain can make it a habit to process anxiety or distress at night in the form of nightmares, resulting in long-term sleep disturbance and increased distress and impairment during the daytime. This daytime distress, including worrying about having another nightmare, then increases the likelihood of more nightmares. Some strategies that people adopt to cope with nightmares, such trying to catch up on sleep during the daytime, delaying going to bed as long as possible, or using drugs or alcohol to fall asleep, can worsen sleep disruption and further increase the odds of ongoing nightmares.

How can I get help for my nightmares?

You do not have to suffer in silence. If you are experiencing problematic nightmares, bring it to the attention of your treatment provider so they can properly assess your symptoms and discuss with you your treatment options.

If you are working with a Behavioral Sleep Medicine provider, you can expect to receive a thorough assessment into your sleep patterns and nightmare experience, and medical and mental health history. Assessment will often involve the use of sleep and nightmare logs to look for patterns. From there, you may be referred to a sleep medicine physician for an overnight sleep study if your provider suspects that there is another sleep disorder present that might be impacting your sleep. If you have limited access to Behavioral Sleep Medicine providers near you, you can locate a provider on the Society for Behavioral Sleep Medicine’s directory who may be able to provide therapy over telehealth. It is also a good idea to speak with your primary care provider if you have concerns about your nightmares.

Treatment for nightmares involves breaking the brain’s “nightmare habit” by creating a new habit for dreaming and improving sleep continuity and quality to reduce the likelihood of awakenings. Nightmare-specific treatment options include imagery rehearsal therapy (IRT), which works for both idiopathic or trauma-related nightmares, or exposure, relaxation, and rescripting therapy, which is specifically tailored for trauma-related nightmares. Another strategy called lucid dreaming is currently being investigated as a treatment option for people with problematic nightmares; in these studies, lucid dreaming is used to help the person recognize they are in a dream and change the dream content while it is happening. In addition, improving sleep quality and reducing disruptions using cognitive-behavioral therapy for insomnia (CBT-I) can reduce nightmares as well, even without directly targeting or changing the nightmare content.

Whether you prefer to work with a treatment provider or to treat your nightmares independently, you have evidence-based options to help you reduce the frequency, intensity, and distress associated with your nightmares.