Mark Blagrove

The relationship of nightmare frequency and nightmare distress to well-being

Nightmares can be defined as very disturbing dreams, the events or emotions of which cause the dreamer to wake up. In contrast, unpleasant dreams can be defined in terms of a negative emotional rating of a dream, irrespective of whether or not the emotions or events of the dream woke the dreamer. This study addresses whether frequency of unpleasant dreams is a better index of low well‐being than is frequency of nightmares. A total of 147 participants reported their nightmare frequency retrospectively and then kept a log of all dreams, including nightmares, for 2 weeks, and rated each dream for pleasantness/unpleasantness. Anxiety, depression, neuroticism, and acute stress were found to be associated with nightmare distress (ND) (the trait‐like general level of distress in waking‐life caused by having nightmares) and prospective frequency of unpleasant dreams, and less so with the mean emotional tone of all dreams, or retrospective or prospective nightmare frequency. Correlations between low well‐being and retrospective nightmare frequency became insignificant when trait ND was controlled for, but correlations with prospective unpleasant dream frequency were maintained. The reporting of nightmares may thus be confounded and modulated by trait ND: such confounding does not occur for the reporting of unpleasant dreams in general. Thus there may be attributional components to deciding that one has been awoken by a dream, which can affect estimated nightmare frequency and its relationship with well‐being. Underestimation of nightmare frequency by the retrospective questionnaire compared with logs was found to be a function of mean dream unpleasantness and ND.

Dreams, images and emotions associated with propofol anaesthesia

One hundred and twelve patients scheduled for day case varicose vein surgery were randomly allocated to one of three groups: total intravenous anaesthesia with propofol, propofol induction followed by inhalational anaesthesia with nitrous oxide and isoflurane or thiopentone induction followed by inhalational anaesthesia with nitrous oxide and isoflurane. Assessments were made in the recovery room of the incidence of dreaming, the content of the dreams and the emotional status of the patients. The groups differed significantly in reporting that they had been dreaming: patients who underwent total intravenous anaesthesia reported the most dreaming and patients who received thiopentone the least. However, despite the large number of case reports of sexual imagery following propofol anaesthesia and despite the two groups who had received propofol experiencing significantly greater happiness upon recovery than the thiopentone group, there were no appreciable differences in the sexual content of the dreams. Each group had only a small number of dreams even remotely related to sex.

Nightmare frequency, personality and acute psychopathology

Abstract There are currently contradictory findings on whether frequency of having nightmares is related to psychopathology. Common drawbacks of many of the studies are the use of a single retrospective questionnaire to assess nightmare frequency and the measurement of stable traits rather than acute stress. In the present study 124 subjects (males, n =32; females, n =92; age 18–70 years) completed the EPQ-RS, the General Health Questionnaire-30, Goughs Creativity Scale and, over 14 days, a contemporaneous log of the incidence of nightmares. The 14-day log method produced a larger estimate of mean nightmare frequency (41.7 per year) than is common with retrospective measures; there was no significant difference in frequency of nightmares between males and females. Nightmare frequency correlated significantly with GHQ acute psychopathology ( r sp =0.26, p =0.002), with comparable scores for females ( r sp =0.28) and males ( r sp =0.23). Females had significant correlations of nightmare frequency with age ( r sp =−0.26, p =0.007), dream recall ( r sp =0.32, p =0.001) and EPQ-Lie score ( r sp =−0.22, p =0.020), whereas males did not: following regression analysis only females had significant determinants of nightmare frequency, these being GHQ acute psychopathology ( β =0.300, p =0.003) and age ( β =−0.232, p =0.020). Neither sex had significant correlations of nightmare frequency with creativity, extraversion, neuroticism or psychoticism.

Lucid dreaming: associations with internal locus of control, need for cognition and creativity

A lucid dream is defined as occurring when an individual becomes aware that they are dreaming, and, while remaining asleep, can control some of the events or content of the dream. Frequent lucid dreamers have previously been shown to be more internal on Rotter’s Locus of Control (LOC) scale than are non-lucid dreamers. The present study found that frequent lucid dreamers (n = 22) had higher scores than non-lucid dreamers (n = 20) on the Internal dimension of Levenson’s LOC scale, but not on Levenson’s LOC Powerful Others and Chance dimensions. Frequent, and also occasional lucid dreamers (n = 15), also scored significantly higher on Need for Cognition and on Gough’s self-assessed Creative Personality scale, than did non-lucid dreamers. The results indicate a continuity between styles of waking and dreaming cognition, just as previous work has shown a continuity of content. # 1999 Elsevier Science Ltd. All rights reserved.

Definitions of Dream: A Paradigm for Comparing Field Descriptive Specific Studies of Dream

A single definition for dreaming is most likely impossible given the wide spectrum of fields engaged in the study of dreaming, and the diversity in currently applied definitions. Many studies do not specify a definition, yet results are likely to be comparable only when comparable definitions of the topic are used. The alternative is to develop a classification system organizing the multiplicity of definitions for dream. A dream should not be exclusively defined as a non-conscious electrophysiologic state. Dreaming is, at least in part, a mental experience that can be described during waking consciousness. Definitions for dreaming should be utilized in research and discussion which address the various axes which define dreaming: Wake/sleep, Recall, and Content.

Assessing the Dream-Lag Effect for REM and NREM Stage 2 Dreams

This study investigates evidence, from dream reports, for memory consolidation during sleep. It is well-known that events and memories from waking life can be incorporated into dreams. These incorporations can be a literal replication of what occurred in waking life, or, more often, they can be partial or indirect. Two types of temporal relationship have been found to characterize the time of occurrence of a daytime event and the reappearance or incorporation of its features in a dream. These temporal relationships are referred to as the day-residue or immediate incorporation effect, where there is the reappearance of features from events occurring on the immediately preceding day, and the dream-lag effect, where there is the reappearance of features from events occurring 5–7 days prior to the dream. Previous work on the dream-lag effect has used spontaneous home recalled dream reports, which can be from Rapid Eye Movement Sleep (REM) and from non-Rapid Eye Movement Sleep (NREM). This study addresses whether the dream-lag effect occurs only for REM sleep dreams, or for both REM and NREM stage 2 (N2) dreams. 20 participants kept a daily diary for over a week before sleeping in the sleep laboratory for 2 nights. REM and N2 dreams collected in the laboratory were transcribed and each participant rated the level of correspondence between every dream report and every diary record. The dream-lag effect was found for REM but not N2 dreams. Further analysis indicated that this result was not due to N2 dream reports being shorter, in terms of number of words, than the REM dream reports. These results provide evidence for a 7-day sleep-dependent non-linear memory consolidation process that is specific to REM sleep, and accord with proposals for the importance of REM sleep to emotional memory consolidation.

Personality and Dream Recall Frequency: Further Negative Findings

On the basis of previous findings of dream recall frequency being associated with thin boundariness and sensitivity we assessed the association between DRF and variables that appear related to these two measures. Data from 93 participants (47 males, 46 females, mean age 21.3 yrs., SD = 3.5) show that dream recall frequency (DRF) correlates marginally with neuroticism (r = .20) and interrogative suggestibility (r = .21), the latter result indicating that DRF obtained by questionnaire may be subject to demand bias. DRF had very low correlations with various other personality variables (need for cognition, personal locus of control, hypochondriasis, morningness-eveningness), and with narrative memory, confabulation of narrative memory, and habitual sleep length. DRF correlated positively with POMS elated (-depressed) for males (r = .31) but negatively for females (r = −.19), this significant difference in correlations may be due to sex differences in DRF in response to stress. The frequent findings of small or nonsignificant correlations between DRF and personality are discussed in terms of similar low correlations in personality psychology, but we conclude that DRF is usually sampled adequately, and that the results of no simple relationship with personality (except boundariness, creativity, and positive attitude towards dreams) are therefore robust and may indicate that dream recall is mainly determined physiologically.

Evaluating the awakening criterion in the definition of nightmares: how certain are people in judging whether a nightmare woke them up?

There is debate about whether to include in the definition of nightmares a criterion that the imagery or emotions of the nightmare caused the person to wake up. This study investigates whether people believe that they can judge this cause of awakening. 42 participants recorded for 14 nights whether they had a dream, and decided for each dream whether it had or had not woken them. They then rated on a 5‐point scale (where 1 = very certain and 5 = very uncertain) how certain they were in their decision of whether or not the dream woke them. Participants’ mean certainty was high for decisions that the dream woke them (mean certainty = 1.60), and for very unpleasant dreams this mean certainty that the dream woke them was very high (mean certainty = 1.27). Dreams judged to have caused awakening were found to be more unpleasant than dreams judged not to have caused awakening. Although the inclusion of the awakening criterion did not increase the association of nightmare frequency with anxiety, there may be other advantages in the use of the awakening criterion.

The effects of improving sleep on mental health (OASIS): a randomised controlled trial with mediation analysis

Summary Background Sleep difficulties might be a contributory causal factor in the occurrence of mental health problems. If this is true, improving sleep should benefit psychological health. We aimed to determine whether treating insomnia leads to a reduction in paranoia and hallucinations. Methods We did this single-blind, randomised controlled trial (OASIS) at 26 UK universities. University students with insomnia were randomly assigned (1:1) with simple randomisation to receive digital cognitive behavioural therapy (CBT) for insomnia or usual care, and the research team were masked to the treatment. Online assessments took place at weeks 0, 3, 10 (end of therapy), and 22. The primary outcome measures were for insomnia, paranoia, and hallucinatory experiences. We did intention-to-treat analyses. The trial is registered with the ISRCTN registry, number ISRCTN61272251. Findings Between March 5, 2015, and Feb 17, 2016, we randomly assigned 3755 participants to receive digital CBT for insomnia (n=1891) or usual practice (n=1864). Compared with usual practice, the sleep intervention at 10 weeks reduced insomnia (adjusted difference 4·78, 95% CI 4·29 to 5·26, Cohens d=1·11; p<0·0001), paranoia (−2·22, −2·98 to −1·45, Cohens d=0·19; p<0·0001), and hallucinations (−1·58, −1·98 to −1·18, Cohens d=0·24; p<0·0001). Insomnia was a mediator of change in paranoia and hallucinations. No adverse events were reported. Interpretation To our knowledge, this is the largest randomised controlled trial of a psychological intervention for a mental health problem. It provides strong evidence that insomnia is a causal factor in the occurrence of psychotic experiences and other mental health problems. Whether the results generalise beyond a student population requires testing. The treatment of disrupted sleep might require a higher priority in mental health provision. Funding Wellcome Trust.

Individual differences in locus of control and the reporting of lucid dreaming

Abstract Lucid dreaming occurs when a sleeping subject becomes aware of being in a dream, and, without waking up, maintains this awareness. This can then result in the conscious control of events or content of the dream. The present study found that high frequency lucid dreamers were significantly more internal on Rotters Locus of Control scale than were subjects who frequently recalled ordinary but non-lucid, dreams. There were no significant mean group differences in creativity or in performance on an embedded-figures test of field-independence.