Abstract Introduction Nightmares are historically underreported despite strong links to insomnia, suicidal ideation, depression, and posttraumatic stress. Trauma-related nightmares (TRN) are central to DSM-5 PTSD criteria, yet population-level patterns of trauma-related versus non–trauma-related content remain poorly understood. Although prior work has examined the diagnostic utility of TRN, it remains unclear how commonly individuals with frequent nightmares report trauma-related themes or whether nightmares emerge or change following trauma exposure. This study addresses these gaps by characterizing nightmare content, onset relative to trauma, and symptom correlates among individuals with clinically significant nightmares. Methods A total of 1,408 college students completed an online survey assessing nightmare characteristics, sleep symptoms, trauma exposure, and mental health symptoms. Measures included nightmare frequency and severity, insomnia symptoms, depressive symptoms, PTSD symptoms, trauma exposure, trauma-related nightmare content, and trauma-related nightmare onset. Analyses focused on participants experiencing nightmares at least weekly (N = 88). Results Among participants with clinically significant nightmares, 46.6% reported that their nightmares began or changed following trauma, and 46.6% reported trauma-related content. Trauma-related and non-trauma-related nightmare groups did not differ in insomnia or depressive symptoms, but those with trauma-related content reported significantly higher nightmare severity and markedly higher PTSD symptoms. A logistic regression predicting trauma-related nightmare content was significant with PTSD symptoms emerging as the only unique predictor (β = .08, p = .007). A multiple regression predicting nightmare severity was also significant, and PTSD symptoms were again the only significant predictor (β = .61, p .001). In either regression model, trauma content, insomnia, and depression did not explain additional variance once PTSD symptoms were included. Conclusion Trauma-related content is not universal among individuals with clinically significant nightmares, and fewer than half report trauma-linked onset or trauma-themed imagery. PTSD symptoms uniquely distinguish trauma-related from non-trauma-related nightmares and uniquely predict nightmare severity, suggesting that PTSD-related distress plays a primary role in shaping nightmare intensity. These findings underscore the importance of assessing PTSD symptom burden when evaluating nightmare presentation, as trauma themes alone do not capture the clinical processes most closely tied to nightmare severity. Support (if any)
Warren et al. (2026) studied this question.