STUDY OBJECTIVES: The relationship between nightmare prevalence, nightmare distress, and self-reported psychological disturbance was assessed prospectively. DESIGN: Differences in self-reported psychological disturbance as a function of nightmare prevalence was investigated by MANCOVA's with non-nightmare dreams as the covariate as well as Pearson correlations. The relative contribution of nightmare prevalence and distress to the prediction of psychological disturbance was investigated through multiple regression analyses. SETTING: N/A. PARTICIPANTS: 116 participants (mean age = 20 years) completed self-report indices of depression, anxiety, dissociation, psychosis-proneness, and a psychiatric symptom checklist and kept a nightmare log for 21 consecutive nights. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Frequent nightmares were associated with higher levels of psychological disturbance. Individuals who reported 3 or more nightmares across the 3 weeks reported more dissociation, psychosis-proneness and psychiatric symptoms than participants reporting 2 nightmares or less. However, nightmare prevalence and distress were not significantly correlated and differentially predicted to different types of waking psychological disturbance. Multiple regressions further indicated that nightmare distress accounted for much of the unique explanatory variance in predicting clinical states associated with high negative affect (anxiety and depression). Last, there was no evidence for a specific relationship between nightmares and psychosis-proneness. CONCLUSIONS: The findings suggest that it is not the incidence of nightmares which is associated with poorer waking psychological functioning, especially anxiety and depression states, but the reported distress associated with the nightmare experience which is the critical variable in predicting higher psychological disturbance.
Factors affecting or inducing nightmares have been investigated repeatedly. However, little research is carried out on the behavioral consequences of nightmares. The present study thus served to investigate behavioral effects of nightmares in correlation to personality variables. 41 non-clinical participants, who suffer from about 2 nightmares per month recorded their dreams and nightmares over a 4-week period. A nightmare was defined as a dream that frightens the dreamer and could be recalled in detail on awakening. Anxiety and mood were monitored every morning. All nightmares and their behavioral consequences were noted on a questionnaire. Personality traits and life events were assessed at the beginning of the investigation. 100 nightmares were reported by the subjects over the 4-week period (range: 0–8). Following a nightmare, the subjects were significantly more anxious and were of a less stable mental condition compared to nights without nightmares. Additionally, nightmares induced physical complaints. This was considered to be an indicator that something was wrong in their lives and induced them to solve personal problems. The behavioral effects were most pronounced in subjects scoring high on neuroticism and on the number of physical complaints and low on achievement orientation and openness. The results suggest that sufferers of nightmares intend to change their lives, especially those with a neurotic-like personality.
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.
OBJECTIVE: Recent clinical trials have included patient complaints of nightmares as a category of reportable medication side effects. This study integrates that data into current experimental and theoretical research of drug effects that may alter dreaming and nightmares. The objective is to provide a clinical and theoretical framework useful in categorizing the potential and reported drug effects on nightmares. METHODOLOGY: This study reviews case reports and clinical trials that have reported nightmares or alterations in dreaming occurring secondary to medication usage. These data are analysed as to the probability of the drug/nightmare association, and integrated into current electrophysiological and neurochemical theories of dreaming and nightmares. RESULTS: Pharmacological agents affecting the neurotransmitters norepinephrine, serotonin and dopamine are clearly associated with patient reports of nightmares. Agents affecting immunological response to infectious disease are likely to induce nightmares in some patients. A possible association exists between reports of nightmares and agents affecting the neurotransmitters acetylcholine, GABA and histamine, as well as for some anesthetics, antipsychotics and antiepileptic agents. CONCLUSION: By utilizing our current experimental and theoretical knowledge base, the potential etiology of a majority of reported drug effects on nightmares can be classified. These data support current neurochemical theories of dreaming, as well as suggesting that the biochemical basis for dreaming and nightmare induction may be more complex than generally suggested.
OBJECTIVE: To compile and assess the English-language literature on drug-induced nightmares, excluding nightmares secondary to drug withdrawal or drug-associated night terrors. DATA SOURCES: Published articles, letters, case reports, and abstracts in English were identified by MEDLINE (1966-May 1998) searches using the search term nightmares, chemically induced. Additional articles were obtained from bibliographies of retrieved articles. DATA EXTRACTION: All case reports of drug-induced nightmares were evaluated using the Naranjo algorithm for causality. Clinical studies of drugs that reported nightmares as an adverse effect were assessed for frequency of occurrence. DATA SYNTHESIS: Nightmares, defined as nocturnal episodes of intense anxiety and fear associated with a vivid, emotionally charged dream experience, are generally classified as a parasomnia. Possible pharmacologic mechanisms for drug-induced nightmares, such as REM suppression and dopamine receptor stimulation, are reviewed. However, the vast majority of therapeutic agents implicated in causing nightmares have no obvious pharmacologic mechanism. CONCLUSIONS: Assessing causality with an event such as a nightmare is difficult because of the high incidence of nightmares in the healthy population. Using qualitative, quantitative, and possible pharmacologic mechanism criteria, it appears that sedative/hypnotics, beta-blockers, and amphetamines are the therapeutic modalities most frequently associated with nightmares. These drug classes have a plausible pharmacologic mechanism to explain this effect. Dopamine agonists also have evidence of causality, with dopamine receptor stimulation as a possible pharmacologic mechanism.
We quantified the genetic influences affecting the liability to nightmares, and the association between nightmares and psychiatric disorders in a community-based sample. In 1990, 1,298 monozygotic (MZ) and 2,419 dizygotic (DZ) twin pairs aged 33-60 years responded to a questionnaire study in the Finnish Twin Cohort. Structural equation modeling was used to estimate genetic and environmental components of variance in the liability to nightmares. Records on hospitalization and long-term antipsychotic medication were used to estimate the period prevalence of serious psychiatric disorders. Nightmares were reported more frequently in females both in childhood and as adults. The correlation between occurrence in childhood and as adults was 0.69 in males and 0.71 in females. Polychoric correlations of occurrence within the twin pairs were 0. 45 in MZ and 0.21 in DZ pairs in childhood, and as adults 0.39 and 0. 18, respectively. The best fitting genetic model was that specifying additive genetic and unshared environmental effects. The estimated proportion of genetic effects in childhood was in males 44% (95% confidence interval [CI] 35-52%) and in females 45% (95% CI 38-52%) of the phenotypic variance. As adults the values were in males 36% (95% CI 27-44%) and in females 38% (95% CI 31-45%). Nightmare frequency and psychiatric disorders were linearly associated. Among those with the most frequent nightmares odds ratios (95% CI) were 3. 67 (2.48-5.42) for childhood and 5.87 (4.08-8.45) for adults compared with those never having nightmares. Nightmares are quite a stable trait from childhood to middle age. There are persistent genetic effects on the disposition to nightmares both in childhood and adulthood. Nightmares are significantly associated with psychiatric disorders.
This consensus paper provides an overview of the state of the art in research on the aetiology and treatment of nightmare disorder and outlines further perspectives on these issues. It presents a definition of nightmares and nightmare disorder followed by epidemiological findings, and then explains existing models of nightmare aetiology in traumatized and non-traumatized individuals. Chronic nightmares develop through the interaction of elevated hyperarousal and impaired fear extinction. This interplay is assumed to be facilitated by trait affect distress elicited by traumatic experiences, early childhood adversity and trait susceptibility, as well as by elevated thought suppression and potentially sleep-disordered breathing. Accordingly, different treatment options for nightmares focus on their meaning, on the chronic repetition of the nightmare or on maladaptive beliefs. Clinically, knowledge of healthcare providers about nightmare disorder and the delivery of evidence-based interventions in the healthcare system is discussed. Based on these findings, we highlight some future perspectives and potential further developments of nightmare treatments and research into nightmare aetiology.
The present research challenges the assumption that nightmare suffering can be operationally defined as nightmare frequency. Four groups of undergraduate students, for a total sample of 540 (358 women, 165 men, 17 undeclared), estimated their nightmare frequency in the prior year and completed a questionnaire assessing the amount of waking distress associated with their nightmares (nightmare distress). This questionnaire included an item on which they indicated their interest in therapy for nightmares. While nightmare frequency was significantly correlated with nightmare distress and interest in therapy, the correlations were sufficiently modest to suggest that these two variables should be differentiated both in theoretical/empirical studies of nightmares and in approaches to treatment with nightmares.
CONTEXT: Chronic nightmares occur frequently in patients with posttraumatic stress disorder (PTSD) but are not usually a primary target of treatment. OBJECTIVE: To determine if treating chronic nightmares with imagery rehearsal therapy (IRT) reduces the frequency of disturbing dreams, improves sleep quality, and decreases PTSD symptom severity. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled trial conducted from 1995 to 1999 among 168 women in New Mexico; 95% had moderate-to-severe PTSD, 97% had experienced rape or other sexual assault, 77% reported life-threatening sexual assault, and 58% reported repeated exposure to sexual abuse in childhood or adolescence. INTERVENTION: Participants were randomized to receive treatment (n = 88) or to the wait-list control group (n = 80). The treatment group received IRT in 3 sessions; controls received no additional intervention, but continued any ongoing treatment. MAIN OUTCOME MEASURES: Scores on the Nightmare Frequency Questionnaire (NFQ), Pittsburgh Sleep Quality Index (PSQI), PTSD Symptom Scale (PSS), and Clinician-Administered PTSD Scale (CAPS) at 3- and 6-month follow-up. RESULTS: A total of 114 participants completed follow-up at 3 and/or 6 months. Comparing baseline to follow-up (n = 97-114), treatment significantly reduced nights per week with nightmares (Cohen d = 1.24; P<.001) and number of nightmares per week (Cohen d = 0.85; P<.001) on the NFQ and improved sleep (on the PSQI, Cohen d = 0.67; P<.001) and PTSD symptoms (on the PSS, Cohen d = 1.00; P<.001 and on the CAPS, Cohen d = 1.53; P<.001). Control participants showed small, nonsignificant improvements for the same measures (mean Cohen d = 0.21). In a 3-point analysis (n = 66-77), improvements occurred in the treatment group at 3-month follow-up (treatment vs control group, Cohen d = 1.15 vs 0.07 for nights per week with nightmares; 0.95 vs -0.06 for nightmares per week; 0.77 vs 0.31 on the PSQI, and 1.06 vs 0.31 on the PSS) and were sustained without further intervention or contact between 3 and 6 months. An intent-to-treat analysis (n = 168) confirmed significant differences between treatment and control groups for nightmares, sleep, and PTSD (all P<.02) with moderate effect sizes for treatment (mean Cohen d = 0.60) and small effect sizes for controls (mean Cohen d = 0.14). Posttraumatic stress symptoms decreased by at least 1 level of clinical severity in 65% of the treatment group compared with symptoms worsening or not changing in 69% of controls (chi(2)(1) = 12.80; P<.001). CONCLUSIONS: Imagery rehearsal therapy is a brief, well-tolerated treatment that appears to decrease chronic nightmares, improve sleep quality, and decrease PTSD symptom severity.
A representative sample of 5,622 subjects between 15 and 96 years of age from the noninstitutionalized general population of France were interviewed by telephone concerning their sleeping habits and sleep disorders. The interviews were conducted using the Sleep-Eval knowledge-based system, a nonmonotonic, level 2 expert system with a causal reasoning mode. Questions investigated nightmares, based on the Diagnostic and Statistical Manual, fourth edition (DSM-IV), definition, psychopathological traits, and included 12 other groups of information, including sociodemographics, sleep-wake schedule, daytime functioning, psychiatric and medical history, and drug intake. The data from 1,049 subjects suffering from insomnia were considered for this analysis. Bivariate analyses, logistic regression analysis using the method of indicator contrasts for the investigation of independent variables, and calculation of significant odds ratios were performed. Nightmares were reported in 18.3% of the surveyed insomniac population and were two times higher in women than in men. The following factors were found to be significantly associated with nightmares 1) sleep with many awakenings, 2) abnormally long sleep onset, 3) daytime memory impairment following poor nocturnal sleep, 4) daytime anxiety following poor nocturnal sleep, and 5) being a woman. There was a strong association between the report of nightmares in women and the presence of either a depressive disorder, anxiety disorder, or both disorders together. When the effects of major psychiatric disorders were controlled for, nightmares were significantly associated with being a woman, feeling depressed after a poor night's sleep, and complaining of a long sleep latency. Nightmares can lead to a negative conditioning toward sleep and to chronic sleep complaints. Considering the frequency of nightmares in an adult insomniac population and the significant relationship between nightmares and certain subgroups, nightmares should receive more attention in patients, especially women complaining of disrupted sleep, as high rates of psychiatric disorders were found in this specific group.
STUDY OBJECTIVES: To determine the prevalence of frequent nightmares and their correlates in a large community-based cohort of middle-aged Hong Kong Chinese. DESIGN: A 2-phase design involving a cross-sectional survey of 8558 subjects (men, 47.6%) with a mean age of 40.9 years (SD 5.5, range 20-78) and subsequently followed by a detailed clinical evaluation of the psychopathology and personality profile of 252 subjects. SETTING: Community. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: The prevalence of frequent nightmares, as defined by at least once per week, was 5.1%. Female sex, low monthly family income, insomnia symptoms, sleep-disordered breathing symptoms, and sleep-related daytime consequences were significantly associated with nightmare frequency. The risk of having a psychiatric disorder was 5.74 times greater for subjects with frequent nightmares (95% confidence interval 2.03-16.26), especially mood disorders (odds ratio = 15.57, 95% confidence interval 3.77-64.37). After exclusion of concomitant psychiatric morbidities, subjects with frequent nightmares still scored significantly higher on neuroticism in the personality scale (p < 0.05). CONCLUSIONS: Frequent nightmares were not uncommon in the general population and were associated with a constellation of factors, including sociodemographic characteristics and comorbid sleep and psychiatric disorders. Moreover, frequent nightmares were independently related to the neuroticism personality trait, irrespective of psychiatric diagnosis. Prospective studies should be conducted to investigate various predisposing, precipitating, and perpetuating factors and the associated repercussions of nightmares.
BACKGROUND: The goal of this pilot study was to evaluate the effects of the cognitive-restructuring technique 'lucid dreaming treatment' (LDT) on chronic nightmares. Becoming lucid (realizing that one is dreaming) during a nightmare allows one to alter the nightmare storyline during the nightmare itself. METHODS: After having filled out a sleep and a posttraumatic stress disorder questionnaire, 23 nightmare sufferers were randomly divided into 3 groups; 8 participants received one 2-hour individual LDT session, 8 participants received one 2-hour group LDT session, and 7 participants were placed on the waiting list. LDT consisted of exposure, mastery, and lucidity exercises. Participants filled out the same questionnaires 12 weeks after the intervention (follow-up). RESULTS: At follow-up the nightmare frequency of both treatment groups had decreased. There were no significant changes in sleep quality and posttraumatic stress disorder symptom severity. Lucidity was not necessary for a reduction in nightmare frequency. CONCLUSIONS: LDT seems effective in reducing nightmare frequency, although the primary therapeutic component (i.e. exposure, mastery, or lucidity) remains unclear.
This study, for the first time, distinguishes between nightmares and bad dreams, measures the frequency of each using dream logs, and separately assesses the relation between nightmares, bad dreams, and well-being. Eighty-nine participants completed 7 measures of well-being and recorded their dreams for 4 consecutive weeks. The dream logs yielded estimated mean annual nightmare and bad-dream frequencies that were significantly (ps < .01) greater than the mean 12-month and 1-month retrospective estimates. Nightmare frequency had more significant correlations than bad-dream frequency with well-being, suggesting that nightmares are a more severe expression of the same basic phenomenon. The findings confirm and extend evidence that nightmares are more prevalent than was previously believed and underscore the need to differentiate nightmares from bad dreams.
STUDY OBJECTIVES: To examine the relationship between the frequency of nightmares and the risk of suicide. DESIGN AND SETTING: A prospective follow-up study in a general population of Finland starting in 1972. PARTICIPANTS: A total of 36,211 subjects (17,700 men and 18,511 women) aged 25-64 years at baseline. INTERVENTIONS: N/A. MEASUREMENTS: The study included self-administered questionnaires (mainly questions on socio-economic factors, medical history, health behavior, and psychosocial factors) and health examination at the local primary healthcare center. The frequency of nightmares was estimated. The subjects were followed until Dec. 31, 1995, or death. Information on deaths caused by suicide (n=159) or other self-inflicted injury was obtained from the National Death Register by computerized record linkage using the national personal identification code assigned to every Finnish resident. Using the Cox proportional hazards regression model we controlled for several potential confounding factors. RESULTS: The frequency of nightmares was directly related to the risk of suicide. Among subjects having nightmares occasionally the adjusted relative risk of suicide was 57% higher, and among those reporting frequent nightmares 105% higher compared with subjects reporting no nightmares at all. CONCLUSIONS: This is the first study to report a direct and graded association between the frequency of nightmares and death from suicide in a general population.
Although several studies have examined the prevalence of nightmares and their relationship to anxiety, this is the first to have used daily dream logs, rather than retrospective self-reports, to monitor nightmare frequency. 220 undergraduates were administered self-report measures of anxiety and for 2 weeks recorded the number of their nightmares in logs. 47% of Ss reported at least one nightmare during the study period. The dream logs yielded an estimated mean annual nightmare frequency of 23.6, which is 2.5 times as great as the estimate yielded by retrospective reports (p less than .01). Nightmare frequency and anxiety were uncorrelated. The findings indicate that nightmares are more prevalent than has been reported, and their frequency unrelated to self-reported anxiety.
UNLABELLED: This is the report of an open label clinical trial to evaluate the effects of nabilone, an endocannabinoid receptor agonist, on treatment-resistant nightmares in patients diagnosed with posttraumatic stress disorder (PTSD). METHODS: Charts of 47 patients diagnosed with PTSD and having continuing nightmares in spite of conventional antidepressants and hypnotics were reviewed after adjunctive treatment with nabilone was initiated. These patients had been referred to a psychiatric specialist outpatient clinic between 2004 and 2006. The majority of patients (72%) receiving nabilone experienced either cessation of nightmares or a significant reduction in nightmare intensity. Subjective improvement in sleep time, the quality of sleep, and the reduction of daytime flashbacks and nightsweats were also noted by some patients. The results of this study indicate the potential benefits of nabilone, a synthetic cannabinoid, in patients with PTSD experiencing poor control of nightmares with standard pharmacotherapy. This is the first report of the use of nabilone (Cesamet; Valeant Canada, Ltd., Montreal, Canada) for the management of treatment-resistant nightmares in PTSD.
OBJECTIVE: The authors conducted a 15-week randomized controlled trial of the alpha-1 adrenoreceptor antagonist prazosin for combat trauma nightmares, sleep quality, global function, and overall symptoms in active-duty soldiers with posttraumatic stress disorder (PTSD) returned from combat deployments to Iraq and Afghanistan. METHOD: Sixty-seven soldiers were randomly assigned to treatment with prazosin or placebo for 15 weeks. Drug was titrated based on nightmare response over 6 weeks to a possible maximum dose of 5 mg midmorning and 20 mg at bedtime for men and 2 mg midmorning and 10 mg at bedtime for women. Mean achieved bedtime doses were 15.6 mg of prazosin (SD=6.0) and 18.8 mg of placebo (SD=3.3) for men and 7.0 mg of prazosin (SD=3.5) and 10.0 mg of placebo (SD=0.0) for women. Mean achieved midmorning doses were 4.0 mg of prazosin (SD=1.4) and 4.8 mg of placebo (SD=0.8) for men and 1.7 mg of prazosin (SD=0.5) and 2.0 mg of placebo (SD=0.0) mg for women. Primary outcome measures were the nightmare item of the Clinician-Administered PTSD Scale (CAPS), the Pittsburgh Sleep Quality Index, and the change item of the Clinical Global Impressions Scale anchored to functioning. Secondary outcome measures were the 17-item CAPS, the Hamilton Depression Rating Scale, the Patient Health Questionnaire-9, and the Quality of Life Index. Maintenance psychotropic medications and supportive psychotherapy were held constant. RESULTS: Prazosin was effective for trauma nightmares, sleep quality, global function, CAPS score, and the CAPS hyperarousal symptom cluster. Prazosin was well tolerated, and blood pressure changes did not differ between groups. CONCLUSIONS: Prazosin is effective for combat-related PTSD with trauma nightmares in active-duty soldiers, and benefits are clinically meaningful. Substantial residual symptoms suggest that studies combining prazosin with effective psychotherapies might demonstrate further benefit.
STUDY OBJECTIVES: The purpose of this study was to investigate whether insomnia symptoms and nightmares are related to suicidal ideation independent of one another and independent of the symptoms of anxiety, depression, and posttraumatic stress disorder (PTSD). DESIGN: The study consisted of questionnaires examining insomnia symptoms and nightmares, and symptoms of depression, anxiety, and PTSD. The questionnaires were administered online. SETTING: University. PATIENTS OR PARTICIPANTS: 583 undergraduate students at a large, public university in southeastern United States. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Results indicated that both nightmares and insomnia symptoms were related to suicidal ideation, independent of one another. Nightmares, but not insomnia symptoms, were related to suicidal ideation after controlling for the symptoms of anxiety, depression, and PTSD. CONCLUSIONS: Nightmares may be more than a marker of PTSD and hence may be important in the identification of suicidal ideation.
Nightmares—vivid, emotionally dysphoric dreams—are quite common and are associated with a broad range of psychiatric conditions. However, the origin of such dreams remains largely unexplained, and there have been no attempts to reconcile repetitive traumatic nightmares with nontraumatic nightmares, dysphoric dreams that do not awaken the dreamer, or with more normative dreams. Based on recent research in cognitive neuroscience, sleep physiology, fear conditioning, and emotional-memory regulation, we propose a multilevel neurocognitive model that unites waking and sleeping as a conceptual framework for understanding a wide spectrum of disturbed dreaming. We propose that normal dreaming serves a fear-extinction function and that nightmares reflect failures in emotion regulation. We further suggest that nightmares occur as a result of two processes that we term affect load—a consequence of daily variations in emotional pressures—and affect distress—a disposition to experience events with high levels of negative emotional reactivity.