Current Psychiatry Reports
February 1, 2016
Michael Schredl
Research on dreaming in people with personality disorders is limited, but studies of borderline personality disorder show that these patients experience negatively toned dreams and more frequent nightmares, and these characteristics are not caused by co-occurring depression or posttraumatic stress disorder. The review suggests future research directions, noting that current findings make this area of study promising. Clinical recommendations focus on treating the commonly co-occurring nightmare disorder.
PLoS One
January 1, 2015
Robin Bekrater-Bodmann, Michael Schredl, Martin Diers et al.
About 22% of 3,234 unilateral limb amputees could not remember their body representation in dreams, 24% always dreamed of themselves as intact, and less than 3% always as impaired; nearly 35% had mixed dreams. Lower-limb amputation and the presence of phantom limb pain and residual limb pain were associated with recalling an impaired body representation in dreams, while non-painful phantom phenomena had no influence. The findings suggest complex interactions between physical body appearance and mental body representation, likely modulated by waking distress.
The American Journal of Psychology
January 1, 2014
Michael Schredl
Women tend to report nightmares more frequently than men, a difference that emerges around age 10. A study in an unselected student sample found that two factors mediate this gender difference: neuroticism and overall dream recall frequency. The effect of neuroticism and the age of emergence suggest that gender-specific socialization processes may play an important role. Previous findings linking nightmare frequency to sex role orientation support this idea, but longitudinal studies are needed to validate these hypotheses.
Laterality
January 1, 2014
Michael Schredl, Alan A Beaton, Josie Henley-Einion et al.
Right-handed and mixed-handed children and adolescents report recalling dreams more often than left-handed individuals, especially among adolescents. In a sample of 3,535 participants aged 6 to 18 years, right- and mixed/inconsistent handedness were linked to higher dream-recall frequency compared to left-handedness, with the effect stronger in adolescents than in children. The reasons for left-handers' lower dream recall remain unknown and require further investigation.
The Behavioral and brain sciences
December 1, 2013
Michael Schredl
Testing whether dreaming contributes to memory consolidation during sleep faces major methodological hurdles, including how dream recall itself affects memory. One promising approach is to study the dreams of individuals who regularly practice the ancient art of memory (AAOM), alongside neuroimaging studies of AAOM practitioners. This line of research could help clarify the relationship between dreaming and off-line memory processing.
Sleep Medicine Reviews
April 1, 2013
Gotthard G. Tribl, Thomas C. Wetter, Michael Schredl
Antidepressants consistently reduce how often people recall their dreams, especially tricyclic antidepressants and phenelzine, with a less consistent effect for SSRIs and SNRIs. Tricyclic antidepressants also make dream content more positive, while withdrawing from them or from MAO inhibitors can cause nightmares. In contrast, taking or withdrawing from SSRIs/SNRIs tends to intensify dreaming, which may sometimes lead to nightmares. These findings come from a systematic review of 21 clinical studies and 25 case reports covering 1950 to 2010, involving both depressed patients and healthy volunteers. The authors note that despite clear pharmacological effects, research on this topic has been scarce over the past 60 years.
Consciousness and Cognition
September 1, 2012
Tadas Stumbrys, Daniel Erlacher, Melanie Schädlich et al.
Lucid dreaming, where the dreamer is aware of dreaming and can often influence the dream, is a learnable skill. A systematic review of 35 studies (11 in sleep laboratories, 24 in the field) evaluated techniques for inducing lucid dreams. Most studies (26) tested cognitive techniques, 11 used external stimulation, and one applied a drug. The overall methodological quality of the studies was low. No induction technique was verified to reliably and consistently induce lucid dreams, though some appeared promising. The review presents a taxonomy of methods and discusses methodological issues and future research directions.
Consciousness and Cognition
December 1, 2011
Michael Schredl
Dreaming in people with schizophrenia has long interested researchers because of similarities between dream experiences and daytime symptoms like bizarre thoughts and hallucinations. However, many dream studies in psychopathology fail to meet standard scientific criteria. This paper examines methodological problems—sampling methods, dream collection, and content analysis—that affect the validity of findings. The authors propose a dimensional approach that directly links the severity of daytime symptoms to specific dream characteristics, which could help identify which schizophrenia symptoms are most closely connected to dream content.
Sleep Medicine Reviews
April 1, 2011
Michael Schredl, Iris Reinhard
Women tend to report nightmares more often than men, but this gender difference does not appear in children or older persons. A meta-analysis of 111 independent studies found that the difference emerges in adolescence, narrows with increasing age, and is influenced by how nightmare frequency is measured—studies using binary (yes/no) items show a smaller difference than those using rating scales. The definition of nightmare did not affect the gender gap. For children, the most influential factor was whether the data came from children's self-reports or parent reports. Candidate explanations such as dream recall frequency, depression, childhood trauma, and insomnia remain unexamined in systematic research on this gender difference.
The American Journal of Psychology
January 1, 2011
Michael Schredl
About 75% of 444 participants, mostly psychology students, had read at least one magazine article on dreams, and over 40% had read at least one book about dreams. A positive attitude toward dreaming was the main factor linked to how often people read dream literature; personality traits played only a minor role. The self-rated benefit of reading such material ranged widely, from not helpful to very helpful, and was associated with how often people recalled their dreams and their positive attitude toward dreaming. More detailed research into what specific information people read could help identify effective dream-work techniques.
Child psychiatry and human development
April 1, 2010
Michael Schredl, Heiko Sartorius
Children with ADHD have more negatively toned dreams than children without ADHD, including more misfortunes, threats, negative endings, and physical aggression toward the dreamer. However, their dream recall frequency, dream length, and dream bizarreness are similar. The findings suggest that dreams reflect the inner world of children with ADHD, and the authors propose studying whether these negative dream patterns change with treatment.
The American Journal of Psychology
January 1, 2010
Michael Schredl, Joelle Alexandra Schawinski
About 14.5% of dreams are shared, and how often people share dreams is independently linked to how often they recall dreams, how often they have nightmares, their attitude toward dreams, gender, extroversion, and thin psychological boundaries. Dream sharing typically occurs with romantic partners, friends, and relatives and is associated with greater relational intimacy and stress relief, especially for nightmares. The authors call for longitudinal studies to separate temporary from stable factors and to confirm the reported benefits of dream sharing on intimacy in relationships and friendships.
Sleep Medicine Reviews
June 1, 2009
Michael Schredl
Dream recall is heightened in people with insomnia, and their dreams reflect current stressors. Breathing-related dreams are rare in sleep apnea patients, while the deregulation of REM sleep in narcolepsy produces more bizarre and negatively toned dreams. These findings support the arousal-retrieval model of dream recall but also indicate that cognitive impairment or micro-arousal may affect dreaming. The content analyses support the continuity hypothesis, which holds that waking-life issues appear in dreams. However, the number of studies is small, and further research is needed.
Imagination, Cognition and Personality
June 1, 2009
Michael Schredl
Dream recall is necessary for studying dream content, so factors like personality traits that influence recall may bias dream research findings. Different aspects of recall—frequency, detail, and long-term memory—are affected by different factors or to different degrees by the same factor, such as imagination. Whether these variables confound content analyses that use different sampling methods (most recent dreams, diary dreams, or laboratory dreams) is not well understood. The results indicate a clear need for systematic research to improve the representativeness of dream content findings.
Perceptual and Motor Skills
June 1, 2009
Michael Schredl
Age, sex, social class, and size of place of residence each have small but significant effects on how often people recall positively toned and neutral dreams. Women and residents of large cities report dreams more often than men and residents of small towns. Dream-recall frequency declines across age groups. For negatively toned dreams, which are recalled less often overall, these sociodemographic effects are less pronounced.
Psychiatry Research
May 30, 2009
Michael Schredl, Mathias Berger, Dieter Riemann
Trimipramine, a sedating tricyclic antidepressant effective for both depression and primary insomnia, does not affect rapid eye movement sleep unlike most other antidepressants. In a large sample of 3,926 depressive outpatients, treatment over four weeks produced a considerable shift in dream emotions toward the positive end of the scale, paralleling a decrease in symptom severity. The effect on dream recall was small and may be explained by a reduction in negatively toned dreams. These findings support the continuity hypothesis of dreaming, showing a close link between waking-life symptomatology and negative dream emotions.
Journal of Sleep Research
June 1, 2008
Michael Schredl, Iris Reinhard
Women tend to recall their dreams more often than men, and this difference varies with age. An analysis of 175 independent studies found that the smallest gender difference occurs in children (effect size 0.097), the largest in adolescents (0.364), and moderate differences in adults (0.242 to 0.270). The pattern suggests that gender-specific 'dream socialization' may explain why the gap emerges and changes across the lifespan, though longitudinal studies are still lacking.
Perceptual and Motor Skills
June 1, 2008
Michael Schredl
In a representative sample of 931 people over 14, age, sex, and size of place of residence each had small but significant effects on how often people recall their dreams. Women and residents of large cities tend to report dreams more often than men and residents of small towns. Dream-recall frequency declines with age. Together these sociodemographic variables account for only a small portion of the variation in dream recall.
Perceptual and Motor Skills
April 1, 2008
Michael Schredl, Iris Reinhard
Longer sleep is expected to increase dream recall because it provides more REM sleep, yet earlier studies on habitual sleep duration and dream recall have shown mixed results, while experimentally changing sleep duration does have a clear effect. Analyzing 444 participants' diaries over 14 days, the authors found that both within-person day-to-day changes and between-person differences in sleep duration influence how often people remember their dreams.
Perceptual and Motor Skills
October 1, 2007
Michael Schredl
Dream recall frequency does not differ significantly across socioeconomic status in a sample of 612 Chinese students from elite, intermediate, and rural schools. Earlier studies had suggested higher socioeconomic status was linked to more frequent dream recall, but this analysis found no such association. The authors suggest future research could explore whether "dream socialization"—such as encouraging children to remember dreams—varies by socioeconomic background and is influenced by culture.
Psychotherapy and Psychosomatics
January 1, 2007
Lutz Wittmann, Michael Schredl, Milton Kramer
Up to 70% of people with posttraumatic stress disorder (PTSD) report posttraumatic nightmares, yet polysomnographic studies show that neither this high rate nor the timing of nightmares across the sleep cycle is explained by altered REM sleep parameters. The idea that reduced dream recall might be a coping mechanism in PTSD is questionable. About 50% of posttraumatic dreams exactly replicate the traumatic event, so dream content is not stereotypical. Data on non-replicative dreams and changes in dream content over time are preliminary. Posttraumatic dreams are linked to psychopathology. Imagery Rehearsal Therapy has repeatedly proven valuable for treating posttraumatic dream disturbance. Understanding these dreams is essential for theories of PTSD and the function of dreaming.
Perceptual and Motor Skills
December 1, 2006
Michael Schredl, Heiko Sartorius
A small positive correlation of .19 between the frequency of dream recall reported by mothers and their children suggests a possible socialization effect on dream recall frequency, consistent with a 1973 hypothesis by Cohen. The study involved 88 mothers (average age 38.7 years) and their children (45 girls, 43 boys; average age 9.9 years).
Perceptual and Motor Skills
June 1, 2006
Michael Schredl, Claudia Barthold, Josepha Zimmer
Nightmare frequency correlates between children and mothers but not between children and fathers, suggesting a socialization effect in which mothers, as primary caregivers, may influence how often children report nightmares. Dream recall frequency shows only a small, nonsignificant relationship between children and mothers. These findings support Cohen's 1973 hypothesis that family environment, particularly maternal influence, shapes nightmare frequency and possibly dream recall.
Sleep Medicine Reviews
February 1, 2006
Victor I. Spoormaker, Michael Schredl, Jan Van den Bout
The DSM-IV-TR definition of nightmares is too narrow, as nightmares can involve emotions other than fear, such as anger or grief, and waking directly from a bad dream does not necessarily increase distress. Measuring nightmare frequency is problematic: polysomnography reduces nightmare frequency, retrospective reports underestimate it, and frequent nightmare sufferers may avoid daily logs. Idiopathic and posttraumatic nightmares differ, with posttraumatic ones linked to more and longer awakenings and both associated with periodic limb movements. Nightmares correlate with neuroticism and general psychopathology, and nightmare distress mediates daily impact. Imagery rehearsal therapy is the preferred cognitive-behavioral treatment, though no randomized controlled trial with an attention control group has been conducted. Nightmares should be treated as a separate, prevalent sleep disorder.
Perceptual and Motor Skills
February 1, 2006
Michael Schredl, Stephany Fulda, Iris Reinhard
No link was found between a full moon and how often people remember their dreams. Diaries kept by 196 participants for 28 to 111 nights showed no association between a full moon and dream recall. Psychological factors may explain why some people believe a full moon affects their dreaming.