Recent research published in the journal Dreaming has provided new insights into what influences nightmares and the distress they cause. The study found that an individual’s long-standing personality traits, rather than their momentary emotional state, play a more critical role in both the occurrence of nightmares and the distress experienced from them.

Nightmares affect between 2.4% and 12% of adults, and their impact extends beyond unpleasant dreams. They have been linked to heightened emotional distress, symptoms of post-traumatic stress, paranoia, and even an increased risk of suicide.

While previous research explored both nightmare frequency (how often they occur) and nightmare distress (how bothersome they are), there has been an ongoing debate about the roles of personality traits (long-term characteristics) versus states (temporary experiences). The new study aimed to clarify how these factors interact and to investigate recently identified traits such as ego strength and emotional regulation.

“I’ve always been interested in understanding why we dream, especially why we have bad dreams or nightmares. The reasons seem both complex and elusive. Since I like a good mystery, I study nightmares,” said study author Liam Kelly, an associate professor of clinical mental health counseling at Neumann University.

“In terms of this particular project, it has long been debated among researchers if dispositional personality factors or current state distress is more responsible for nightmares. In my own research I have consistently found traits to be better predictors of nightmares compared to states, at least when examined individually.

“However, previous studies have tended to favor state distress as a better predictor over traits. It stood out to us that previous studies only included a few specific traits. So, it seemed they might be missing part of the picture. In our study we wanted to see if including additional traits that seem important influences of nightmares would make a difference.”

For their study, the researchers recruited 166 university students who were enrolled in psychology courses at a small university in the United States. Participants had an average age of 20.8 years and were fairly diverse in terms of gender, with an even split between male and female students.

To assess nightmare frequency, the participants were asked to recall the number of nights they experienced nightmares over the past two weeks, as well as the total number of nightmares they had during that period. To assess how distressing the nightmares were to participants, the researchers employed two items from the Nightmare Experience Scale: “I am bothered by my nightmares” and “Intense nightmares are a problem for me.” The participants also completed the Nightmare Proneness Scale, which measures the tendency to experience frequent nightmares (e.g., “Many nights I cannot get to sleep because of worry or tension”).

Several scales were used to evaluate the participants’ psychological traits and states. The Ego Strength Scale was used to assess an individual’s capacity to manage stress and maintain psychological stability, while the General Emotion Dysregulation Measure was used to assess how often and intensely individuals experience uncontrolled emotions.

Participants’ tendency to experience negative emotions was measured using a 12-item short form of the Eysenck Personality Questionnaire-Revised, Neuroticism Scale and the Boundary Questionnaire-13 was employed to measure the thinness of psychological boundaries, which indicates how distinct or blurred an individual’s mental and emotional experiences are.

Finally, the ability to become deeply immersed in mental activities was assessed using a 12-item version of Tellegen’s Absorption Scale and the Symptom Checklist-10R was used to measure the level of psychological distress participants experienced in the week prior to the assessment.

The researchers found that nightmare frequency was most strongly associated with nightmare proneness and psychological boundaries. Interestingly, lower scores on the boundaries scale (indicative of less clear mental divisions) predicted a higher frequency of nightmares. Nightmare distress, on the other hand, was most significantly linked to low ego strength and high emotional dysregulation, suggesting that individuals with weaker capacities to manage stress and regulate emotions experience more distress from their nightmares.

“One general takeaway is that nightmare experiences seem more influenced by how the individual’s mind is put together and how one tends to respond to situations rather than how distressed they are at a given time,” Kelly told PsyPost. “Of course, it could be a combination of state distress and traits influencing nightmares, but our data did not show that.”

“It seems that the influences of having nightmares are different than the influences of being upset by nightmares.”

“Having nightmares seems influenced by how the mind is organized and experiences things,” Kelly explained. “Individuals with nightmares seem to be more sensitive and vulnerable and experience vague, confusing inner states in a more tangible way, like nightmares.”

“On the other hand, being upset by nightmares seems more related to being able to manage how intensely we react to threatening experiences. After all, nightmares can be scary. Individuals who react strongly to their nightmares tend to have more difficulty regulating their reactions and adapting to other situations as well. This makes some sense since we have the same mind both when awake and asleep.”

“What was most surprising to me is that ego strength was a strong predictor of nightmare distress rather than nightmare frequency, which was a previous finding,” Kelly said. “But I think this unexpected finding, and the results overall, tell us that different aspects of the personality are related to different aspects of dream experiences and how we react to them.”

But as with all research, there are some limitations to consider. The study used a relatively homogeneous sample of young adults and relied on self-report questionnaires, which could introduce biases. Future research could expand to more diverse populations and include assessments of sensory sensitivity, trauma history, and different types of nightmares.

“The study data was all based on retrospective self-reports from a college student sample. This may limit being able to apply the findings to different groups of people,” Kelly noted. “One area that I would like to study more is nightmare proneness. If its concretization process is a real thing, and it seems like it is, this could be a key to understanding what’s going on in the mind to create the imagery and story lines of nightmares.”

The study, “Revisiting Trait and State Predictors of Nightmare Frequency and Nightmare Distress,” was authored by William E. Kelly and John R. Mathe.