Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT)
June 10, 2018
Gotthard G. Tribl, Franziska Beuerle, Mateus C. Trindade et al.
1 citation
Dreams reflect waking-life experiences, including personal concerns and cultural environment. Comparing written dream reports from Brazilian and German samples revealed both cultural differences and universal similarities. German dream reports contained more bizarreness, aggression, problems, and extreme emotions, while Brazilian reports featured more depression-related topics and work- and leisure-related themes. Similarities included verbal and physical interaction, numbers of male and female characters, and death-related themes, suggesting universal dream characteristics. The differences are interpreted as reflecting core cultural patterns: for Brazil, themes of miscegenation, emotional culture, and saudade (longing); for Germany, a conflict between high performance in science and arts and twentieth-century history.
University Library Heidelberg
January 26, 2026
Michael Schredl, Anja S. Göritz
About 11% of remembered dreams affect daytime mood, supporting an expanded continuity hypothesis where dreams not only reflect but also influence waking life. A survey of 2,492 adults (mean age 47.75 years) found that nightmare frequency, dream recall frequency, attitude toward dreams, neuroticism, openness to experience, gender, and age all influence how dreams affect daytime mood. The findings suggest that for some individuals—particularly women and those with high neuroticism—dreams may have a clinically significant impact on waking life, pointing to a need for further research into a descriptive model linking thematic content and emotions between dream and waking consciousness.
Journal of Homosexuality
October 31, 2024
Johann Dietze, Michael Schredl, Ulrike A. Gisch
Homosexual and heterosexual men share a similar dream pattern, though some differences reflect waking-life experiences. Among 119 German-speaking men, homosexual men reported more sexual partners in waking life, lower satisfaction with their sexual orientation, and more sexual dreams than heterosexual men. Dream reports showed no group differences in dream recall frequency, emotional tone, nightmare frequency, distress, or number of sexual interactions or partners. However, homosexual men's dreams contained a higher ratio of male to female characters and more romantic relationships with men. These findings partially support the continuity hypothesis, indicating that dream content mirrors social interactions and romantic preferences, and underscore the importance of considering sexual orientation in dream research.
Somnologie - Schlafforschung und Schlafmedizin
December 8, 2023
Michael Schredl
Adolescents with frequent nightmares rarely seek professional help. In a study of 100 adolescents aged around 15 years, none had ever sought help for nightmares, even though 21 reported having nightmares once a week or more often or found them quite or very distressing. Nightmares are linked to mental health problems in adolescents and can continue into adulthood, highlighting the need to find ways to reduce untreated nightmare sufferers in this age group.
University Library Heidelberg
January 14, 2021
Michael Schredl
Dreams may reflect long-term environmental changes. Over 30 years, a single dreamer recorded 11,808 dreams, and analysis showed that cold-related elements such as snow, ice, and hail appeared less frequently over time. This suggests that dream content could offer clues about global climate shifts. The authors propose that digital dream analysis tools could help validate this preliminary finding with other large datasets.
heiDOK (Heidelberg University)
January 1, 2010
Michael Schredl, Daniel Erlacher
The International Journal of Dream Research is now in its third year, having published 13 original papers and one invited essay across two issues in 2009. The articles addressed a broad range of topics including lucid dreaming, dream recall, dream content, nightmares, the relationship between dreams and psychopathology, and sleep quality. Submissions came from Canada, the United States, the United Kingdom, the United Arab Emirates, Switzerland, Austria, and Germany, demonstrating the journal's international reach.
heiDOK (Heidelberg University)
January 1, 2010
Michael Schredl
A review of Wilhelm Weygandt's dissertation, supervised by Wilhelm Wundt, argues that his claim that all dreams originate from sensory impressions is no longer valid. However, his careful observations and experiments produced interesting results that merit further study with modern methods, such as investigating the effect of internal stimuli on dream content.
Imagination, Cognition and Personality
September 1, 2025
Michael Schredl, Anja S. Göritz
The Lucid Dreaming Skills Questionnaire (LUSK) reliably measures differences in people's ability to control their dreams while lucid. A study of 1,267 people found the questionnaire valid. In a subset of 374 people tested again after seven years, LUSK scores were less stable than how often people reported having lucid dreams. Those who actively practiced lucid dreaming over the seven years showed a greater increase in lucid dream frequency than those who did not, suggesting that lucid dream induction can succeed outside formal research settings.
European Archives of Psychiatry and Clinical Neuroscience
June 1, 2025
Michael Schredl, Elisabeth Anzenberger, Claudia Schilling
Among psychiatric inpatients, nightmares occurring once per week or more often were reported by 61.54% of those with PTSD (13 patients) and 40.32% of those without PTSD (62 patients). Higher depression scores and a PTSD diagnosis were linked to greater nightmare distress. The findings suggest that frequent nightmares are common in this population and that future work should explore the relationship between psychopathology and nightmares, as well as whether nightmare-focused treatments such as Imagery Rehearsal Therapy could help.
Somnologie
September 1, 2023
Emma Peters, Daniel Erlacher, Friedrich Müller et al.
Acoustic suggestion can help inexperienced people have lucid dreams, but adding hypnosis does not improve the effect. Lucid dreaming is when a person becomes aware they are dreaming, which can be useful for personal growth, sports, and therapy. In this experiment, 10 participants were tested under three conditions: control (acoustic stimulation without suggestion), acoustic suggestion, and hypnotic enhancement of acoustic suggestion. Based on strict verification by the dreamer, external raters, and eye movements, 3% of dream reports were lucid in the control condition, 6% in the acoustic suggestion condition, and 6% in the hypnosis condition.
Clocks & Sleep
September 1, 2022
Michael Schredl, Claudia Schilling
Dysfunctional sleep-related metacognitions (thoughts about one's own thinking during sleep) are linked to more negatively toned dreams and nightmares, even after accounting for a person's general tendency to become aroused. In a study of 919 patients with sleep disorders, those who scored higher on a measure of sleep-related metacognitions reported more nightmares and more negative dream emotions. The effect of metacognitions was small, while the effect of trait arousability was medium. The findings suggest that metacognitive therapy, which targets these sleep-related thoughts, might also improve dream quality by reducing nightmares and increasing positive dream emotions.
Pastoral Psychology
January 1, 2022
Kelly Bulkeley, Michael Schredl
In the wake of the 2020 protests after George Floyd's murder, an online survey of 4,947 American adults found that those who support the Black Lives Matter movement, are highly educated, or have high dream recall were most likely to dream about the protests. The dreams were anxious, fearful, and nightmarish, featuring themes such as George Floyd, participating in protests, threats to home, pandemic concerns, and conversations about BLM. The findings indicate that dreams, dream recall, and dream sharing vary by racial, ethnic, and cultural backgrounds, and that dreams contain meaningful content tied to current events.
Somnologie
September 1, 2021
Katharina Lüth, Judith Schmitt, Michael Schredl
A single 30-minute telephone counseling session that included information on nightmare causes and a shortened version of imagery rehearsal therapy (IRT), followed by 8 weeks of self-practice, significantly reduced both nightmare frequency and distress in 28 participants drawn from a student group and a sleep-laboratory patient group. Effect sizes were very high compared to waiting-list control groups in similar studies. The approach may offer a low-threshold intervention for nightmare sufferers who rarely seek help.
Animals : an open access journal from MDPI
October 19, 2020
Michael Schredl, Christian Bailer, Muriel Sophie Weigel et al.
Dogs appear in about 5% of remembered dreams on average, but this percentage is much higher among dog owners and people with close contact with dogs. Active time spent with a dog and proximity during sleep are also linked to a higher percentage of dreams that include dogs. Although dog dreams are generally more positively toned than other dreams, about 11% of dog dreams involve threatening dogs. People who had negative waking-life experiences with dogs reported more threatening dog dreams. These findings support the continuity hypothesis of dreaming, which holds that dream content reflects waking-life experiences.
Clocks & Sleep
September 1, 2020
Michael Schredl, Anja S. Göritz
Eveningness (being an 'owl') is linked to more frequent nightmares, but this relationship is mediated by neuroticism. Morningness (being a 'lark') is associated with higher dream recall than late bedtime preferences. Urbanicity—being raised in or currently living in an urban area—was not related to nightmare frequency but was linked to lower nightmare distress, suggesting that beliefs about nightmares may influence distress levels. These findings come from an online survey of 2,492 adults (mean age 47.75 years) and highlight unresolved questions about how nightmares, chronotype, and urbanicity interact.
Journal of Sleep Research
February 1, 2019
Sarah F. Schoch, Maren J. Cordi, Michael Schredl et al.
Awakenings to collect dream reports impair subjective and objective sleep quality but do not affect sleep-associated memory consolidation in a word-picture association learning task. Memories of the learning task are successfully incorporated into dreams collected during the night, but not into morning dream reports. Incorporation into non-rapid eye movement sleep dreams, but not rapid eye movement sleep dreams, positively predicts memory performance the next morning. The findings suggest that awakenings are a suitable method for dream and memory studies, and that non-rapid eye movement sleep dreams may be more related to memory consolidation processes than rapid eye movement sleep dreams.
European Journal of Psychotraumatology
January 1, 2019
Robert-Jacek Gorzka, Katja Rebling, Helge Höllmer et al.
The Hamburg Nightmare Questionnaire (HNQ) is a short self-rating instrument developed to assess nightmares, differentiate between nightmare types, and measure their impact on daytime functioning. In a sample of 707 German soldiers, the HNQ showed satisfactory psychometric properties, including a sound factorial structure, adequate internal consistency, and initial indications of construct validity for its subscales. The HNQ is a reliable and economic tool for assessing posttraumatic nightmares in clinical and research settings.
Sleep science (Sao Paulo, Brazil)
January 1, 2019
Michael Schredl, Anja S Goeritz
Nightmare distress—the sleep or mood disturbances that make nightmares a clinical problem—depends on more than just how often nightmares occur. A survey of 2,492 adults found that heightened emotional reactivity, measured as neuroticism, contributes to global nightmare distress, supporting the neurocognitive model of Levin and Nielsen (2007). Recurring nightmares linked to a waking-life event were associated with even higher distress. The authors suggest future research use diagnostic interviews to better understand nightmare disorder and its related variables.
Imagination, Cognition and Personality
September 1, 2018
Michael Schredl, Alina Noveski
Lucid dreams are quite rare, occurring in only 1.36% of dreams in an unselected student sample. Keeping a dream diary over two weeks produced a lower frequency of lucid dreams than retrospective estimates. A negative association between lucid dream frequency and agreeableness was previously reported, and a new finding shows a negative correlation with neuroticism. Many lucid dreams did not include dream control. The authors suggest further study of personality, especially neuroticism and agreeableness, in relation to lucid dreaming.
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine
March 15, 2018
Michael Schredl, Anja S. Göritz
Nightmares involve a wider range of emotions and topics than the standard definitions suggest. Analyzing 1,216 recent nightmares (including childhood nightmares) from a population-based sample, the study found common themes such as being chased, physical aggression, and death or injury of close persons. Less frequent themes, like being the aggressor and suicide, may relate to waking-life psychopathology. The variety of nightmare topics indicates that current diagnostic criteria, which focus mainly on threats to survival or physical integrity, are too narrow. Future research should examine nightmare content specifically in individuals diagnosed with nightmare disorder.
Journal of Sports Sciences
December 1, 2017
Melanie Schädlich, Daniel Erlacher, Michael Schredl
Practicing a motor skill inside a lucid dream can improve real-world performance, but only when distractions during the dream are minimal. In a sleep-laboratory pilot study, participants threw darts in the evening and again in the morning. One group physically practiced, one practiced only in lucid dreams, and a control group did not practice. Lucid dreamers who reported few distractions improved their dart-throwing accuracy by 18%, a significant gain comparable to physical practice. Those who experienced many distractions showed no improvement. The findings suggest lucid dream practice may be useful for athletes who can maintain focus within the dream, though the results are preliminary and require qualitative investigation of the dream experience.
European Archives of Psychiatry and Clinical Neuroscience
February 1, 2017
Michael Schredl, J Malte Bumb, Barbara Alm et al.
Nightmare frequency is elevated in adults with attention-deficit hyperactivity disorder (ADHD). In a sample of 65 ADHD patients, 4.62% reported frequent nightmares (once a week or more), compared to 1.77% of a representative German control sample. This increase was not explained by higher general dream recall or by the presence of a comorbid mental disorder. The authors suggest that clinicians should ask about nightmares when diagnosing ADHD and consider whether established nightmare treatments, such as imagery rehearsal therapy, could help affected patients.
BMC Pregnancy and Childbirth
November 9, 2016
Michael Schredl, Maria Gilles, Isabell Wolf et al.
Pregnant women in their last trimester report nightmares more often than a representative sample of women aged 14 to 93. Nightmare frequency is closely related to subjectively experienced stress during daytime. Baby-related dreams were correlated with nightmare frequency but not with daytime stress. The findings suggest that stress plays a key role in nightmares during pregnancy, and future research should examine nightmare disorders in pregnancy and whether brief interventions like Imagery Rehearsal Therapy could help.
Imagination, Cognition and Personality
September 1, 2016
Michael Schredl, Josie Henley-Einion, Mark Blagrove
Sharing dreams with others is very common. Among 1,375 participants, the frequency of dream sharing is linked to gender in adolescents (girls share more often than boys), extraversion, how often people recall their dreams, and how often they have nightmares. The authors suggest future research should examine with whom dreams are shared and whether sharing dreams has beneficial effects.
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine
July 15, 2016
Michael Schredl, Lara Dehmlow, Judith Schmitt
About 20% of 1,125 patients at a sleep center expressed interest in learning more about nightmare causes and treatments, including those who had never sought help before. The findings suggest that nightmares are underdiagnosed and undertreated even in specialized settings, and that health care professionals should routinely ask about nightmares and consider offering internet-based self-help programs as an initial step.