A preliminary study of the personality of the nightmare sufferer: relationship to schizophrenia and creativity?

Factor Analysis and Validation of the Disturbing Dream and Nightmare Severity Index in an Inpatient Sample

STUDY OBJECTIVES

The Disturbing Dream and Nightmare Severity Index (DDNSI) has been used widely in research and clinical practice without psychometric evidence supporting its use in clinical samples. The present study aimed to explore and confirm the factor structure of the DDNSI in an inpatient sample. We also sought to test the measure's construct validity.

METHODS

Two samples of U.S. inpatients including adult (N = 937) and adolescent (N = 274) participants provided data on nightmares (i.e. DDNSI), sleep quality (i.e. the Pittsburgh Sleep Quality Index) and related psychopathology symptoms (e.g. depression, posttraumatic stress disorder, anxiety).

RESULTS

Exploratory and confirmatory factor analyses found the six original items of the DDNSI to load onto a single latent factor.

CONCLUSIONS

The DDNSI was found to be a valid measure of nightmare frequency and distress, as it was significantly correlated with the items related to disturbing dreams, and the DDNSI was able to differentiate between nightmares and psychopathology symptoms. Though this research comes nearly two decades after the initial creation and use of the DDNSI, it provides a foundation for the scientific rigor of previous and future studies on nightmares using the DDNSI.

The Parasomnias and Sleep Related Movement Disorders—A Look Back at Six Decades of Scientific Studies

The objective of this article is to provide a comprehensive personal survey of all the major parasomnias with coverage of their clinical presentation, investigation, physiopathogenesis and treatment. These include the four major members of the slow-wave sleep arousal parasomnias which are enuresis nocturna (bedwetting), somnambulism (sleepwalking), sleep terrors (pavor nocturnus in children, incubus attacks in adults) and confusional arousals (sleep drunkenness). Other parasomnias covered are sleep-related aggression, hypnagogic and hypnopompic terrifying hallucinations, REM sleep terrifying dreams, nocturnal anxiety attacks, sleep paralysis, sleep talking (somniloquy), sexsomnia, REM sleep behavior disorder (RBD), nocturnal paroxysmal dystonia, sleep starts (hypnic jerks), jactatio capitis nocturna (head and total body rocking), periodic limb movement disorder (PLMs), hypnagogic foot tremor, restless leg syndrome (Ekbom syndrome), exploding head syndrome, excessive fragmentary myoclonus, nocturnal cramps, and sleep-related epileptic seizures. There is interest in the possibility of relationships between sleep/wake states and creativity.

Treatment of Nightmares in Psychiatric Inpatients With Imagery Rehearsal Therapy: An Open Trial and Case Series

Objectives: This study sought to assess the utility of Imagery Rehearsal Therapy (IRT) for nightmares in an inpatient psychiatric setting. Although IRT enjoys a substantial evidence base for efficacy in various populations, data with psychiatric inpatients are lacking. Participants: Participants were 20 adult psychiatric inpatients (11 male, 9 female; mean age=43.4), in an extended stay psychiatric inpatient facility. All participants were diagnosed with multiple, treatment resistant, comorbid conditions, including mood disorders, anxiety disorders, personality disorders, and substance-related disorders. Patients with active psychosis or significant cognitive impairment were excluded. Methods: This was an open trial utilizing a case series design. In addition to routine hospital treatment that included psychotherapeutic and pharmacological interventions, participants received IRT over a span of 3 weeks in 4 small group sessions. Included were education about sleep and nightmares, instruction in writing new dream narratives and practicing guided imagery, and support via further consultation and trouble-shooting. Patients were referred by their psychiatrist or were self-referred, with approval from their treatment teams. Results: Results showed significant aggregate reductions in nightmare frequency and intensity, as well as improvement in sleep overall. Patients also improved on a variety of other symptom measures, including suicidal ideation. No adverse reactions were observed. The present report includes a sampling of individual case vignettes to illustrate variability in treatment response. Conclusions: This study provides preliminary evidence that IRT can be used safely and effectively in a hospital environment to benefit patients suffering from serious mental illnesses, often in the midst of significant life crises. It is not possible in this preliminary study to conclude that IRT specifically (as opposed to other aspects of hospital treatment) produced these outcomes. Larger, controlled trials are needed to establish a causal connection between IRT and nightmare reduction.

Relations among Nightmare Frequency and Ego Strength, Death Anxiety, and Sex of College Students

The present study was designed to investigate empirically the relationship between self-reports of nightmare frequency and ego strength and death anxiety in both men and women. In addition, the interrelations among these variables were assessed. 20 undergraduates with high frequencies of nightmares and 20 with low frequencies (10 men and 10 women per group) were administered the Barron Ego Strength Scale and a death anxiety scale. Significant differences were found between nightmare groups on the Barron scale for men and women but none on the death anxiety scale either by nightmare frequency or sex. A significant negative correlation of -.47 between death anxiety and ego strength was found for women and in one high frequency group. Women with high frequencies of nightmares showed the highest correlation, -.83. These data suggest that nightmare frequency may be a mediating factor in the relationship between ego strength, death anxiety, and sex of subject.

The factor structure, reliability and validity of the Chinese version of the Van Dream Anxiety Scale

BACKGROUND/PURPOSE

Dream emotions and contents are associated with psychological well-being. Dream disturbances, such as frequent nightmares and dream anxiety, are associated with a variety of psychopathological conditions. Therefore, it is important to consider nightmares and the resulting dream anxiety. To address this issue, the Van Dream Anxiety Scale (VDAS) was designed especially for measuring nightmare frequency and dream anxiety caused by frightening dreams. As a Chinese version of VDAS may be helpful in promoting study of nightmare and dream anxiety among Chinese population, in the current study, we sought to develop a Chinese version of the VDAS (CVDAS).

METHODS

We translated the VDAS into Chinese. To evaluate its validity and reliability, a sample of 1,081 Chinese college students from two universities answered the CVDAS, GAD-7, PHQ-9 and EPQ-R-N. Ninety of them answered the CVDAS twice. We also conducted exploratory factor analysis (EFA) to explore the structure of CVDAS.

RESULTS

Excellent internal consistency (Cronbach's alpha coefficient was 0.926), split-half reliability (equal-length Spearman-Brown coefficient was 0.938) and good test-retest reliability (the intraclass correlation coefficient was 0.942 and t=-1.478, P=0.143) of the CVDAS was presented. Exploratory factor analyses indicated a two-factor structure: sleep-related disturbances caused by nightmares and dysfunction caused by nightmares. Convergent and divergent validities were acceptable.

CONCLUSION

The CVDAS shows promise for the measurement of nightmare frequency and specific dream anxiety in Chinese population. Future study should confirm the reliability and validity in the clinical population and further improve this scale.

Cognitive Style and Perception: The Relationship of Boundary Thinness to Visual-Spatial Processing in Dreaming and Waking Thought

The present study investigated empirically whether individuals with thin boundaries as determined by high scores on the Hartmann Boundary Questionnaire (HBQ) [1] demonstrated heightened access to imagistic stimuli than thick boundary individuals. Two independent samples, visual art students and Wall Street brokers, were administered the Rorschach, a sleep and dreaming questionnaire, and a subliminal perception task which involved the presentation of both a subliminal and supraliminal stimulus. As expected, the majority of the visual artists scored thin boundaried and the majority of Wall Street brokers scored thick boundaried on the HBQ. Boundary thinness on the HBQ was positively correlated with Rorschach boundary disruption, higher dream recall, greater reported dream salience, and increased access to subliminal activation. These data are consistent with previous data [2] and support the contention that boundaries are a useful variable in conceptualizing how individuals process imagistically-based emotionally-toned information.

The Relation of Fantasy Proneness, Psychological Absorption, and Imaginative Involvement to Nightmare Prevalence and Nightmare Distress

The present study prospectively investigated the relationship between nightmare prevalence, nightmare distress, and waking imaginative involvement. One hundred and sixteen individuals completed self-report indices of fantasy proneness, psychological absorption, and daydreaming as well as a sleep and dreaming questionnaire and a nightmare distress measure. Participants then kept a dreaming and nightmare log for 21 consecutive nights. As predicted, both nightmare prevalence and nightmare distress were associated with higher levels of fantasy proneness, psychological absorption, and a guilty-dysphoric daydreaming style but not with positively-toned daydreams or a highly distractible daydreaming style. Further, these results were not due to higher levels of overall dream recall. Last, these effects were additive as high scores on either fantasy proneness or absorption added significantly higher incremental validity to the prediction of nightmare prevalence and distress than just from the dysphoric daydreaming measure alone. The results are discussed within the context of emerging etiological theories of nightmare production.

Nightmares: Under-Reported, Undetected, and Therefore Untreated

OBJECTIVE

Nightmares are a robust and modifiable predictor of increased suicidality and poor psychiatric outcomes, yet nightmare screening and treatment remain rare, even in sleep centers. This paper aims to examine what proportion of nightmare sufferers have discussed nightmares with a healthcare provider, as well as possible explanations for low rates of nightmare complaints.

METHODS

The present study utilized a large United States community sample recruited through mTurk and a student sample recruited from a large public university in the Southeast United States. In Study 1, participants (n = 809) were asked whether they had discussed nightmares with a healthcare provider. In Study 2 participants (n = 747) were asked whether they believed nightmares were treatable in addition to whether or not they had discussed nightmares with a healthcare provider.

RESULTS

Of the participants in Study 1 experiencing clinically significant nightmare symptoms only 37.8% of participants reported discussing their nightmares with a healthcare professional. In Study 2 only 11.1% of participants with significant nightmares reporting having told a healthcare provider about their nightmares. Further, of these individuals with clinically significant nightmare symptoms, less than one-third believed that nightmares were treatable. Higher nightmare severity was associated with a greater likelihood of reporting nightmares to a healthcare physician as well as with lower beliefs that nightmares are treatable.

CONCLUSIONS

Our findings suggest that nightmares are rarely reported to healthcare providers, which may explain the underutilization of nightmare treatments. Given the poor outcomes associated with nightmares, nightmare screening is warranted.

Nightmares affect the experience of sleep quality but not sleep architecture: an ambulatory polysomnographic study

BACKGROUND

Nightmares and bad dreams are common in people with emotional disturbances. For example, nightmares are a core symptom in posttraumatic stress disorder and about 50% of borderline personality disorder patients suffer from frequent nightmares. Independent of mental disorders, nightmares are often associated with sleep problems such as prolonged sleep latencies, poorer sleep quality, and daytime sleepiness. It has not been well documented whether this is reflected in objectively quantifiable physiological indices of sleep quality.

METHODS

Questionnaires regarding subjective sleep quality and ambulatory polysomnographic recordings of objective sleep parameters were collected during three consecutive nights in 17 individuals with frequent nightmares (NM) and 17 healthy control participants (HC).

RESULTS

NM participants reported worse sleep quality, more waking problems and more severe insomnia compared to HC group. However, sleep measures obtained by ambulatory polysomnographic recordings revealed no group differences in (a) overall sleep architecture, (b) sleep cycle duration as well as REM density and REM duration in each cycle and (c) sleep architecture when only nights with nightmares were analyzed.

CONCLUSIONS

Our findings support the observation that nightmares result in significant impairment which is independent from disturbed sleep architecture. Thus, these specific problems require specific attention and appropriate treatment.

Childhood parasomnias and psychotic experiences at age 12 years in a United Kingdom birth cohort

STUDY OBJECTIVES

To examine associations between specific parasomnias and psychotic experiences in childhood.

DESIGN

Birth cohort study. Information on the presence of frequent nightmares in children was obtained prospectively from mothers during multiple assessments conducted when children were aged between 2.5 and 9 y. Children were interviewed at age 12 y about nightmares, night terrors, sleepwalking, and psychotic experiences (delusions, hallucinations, and thought interference) occurring in the previous 6 mo.

SETTING

Assessments were completed in participants' homes or a University clinic within the UK.

PATIENTS OR PARTICIPANTS

There were 6,796 children (3,462 girls, 50.9%) who completed the psychotic experiences interview.

MEASUREMENTS AND RESULTS

Children who were reported by their mothers as experiencing frequent nightmares between 2.5 and 9 y of age were more likely to report psychotic experiences at age 12 y, regardless of sex, family adversity, emotional or behavioral problems, IQ and potential neurological problems (odds ratio (OR) = 1.16, [95% confidence intervals (CI) = 1.00, 1.35], P = 0.049). Children reporting any of the parasomnias at age 12 y also had higher rates of concurrent psychotic experiences than those without such sleeping problems, when adjusting for all confounders (OR = 3.62 [95% CI = 2.57, 5.11], P < 0.001). Difficulty getting to sleep and night waking were not found to be associated with psychotic experiences at age 12 y when controlling for confounders.

CONCLUSION

Nightmares and night terrors, but not other sleeping problems, in childhood were associated with psychotic experiences at age 12 years. These findings tentatively suggest that arousal and rapid eye movement forms of sleep disorder might be early indicators of susceptibility to psychotic experiences.

Bad dream frequency in older adults with generalized anxiety disorder: prevalence, correlates, and effect of cognitive behavioral treatment for anxiety

This study investigated the relation between generalized anxiety disorder (GAD) and frequency of bad dreams in older adults. A secondary analysis from a randomized clinical trial comparing cognitive behavioral therapy (CBT) for anxiety to enhanced usual care (EUC) assessed bad dream frequency at baseline, post treatment (3 months), and at 6, 9, 12, and 15 months. Of 227 participants (mean age = 67.4), 134 met GAD diagnostic criteria (CBT = 70, EUC = 64), with the remaining 93 serving as a comparison group. Patients with GAD had significantly more bad dreams than those without, and bad dream frequency was significantly associated with depression, anxiety, worry, and poor quality of life. CBT for anxiety significantly reduced bad dream frequency at post treatment and throughout follow up compared to EUC.

Sleep and borderline personality disorder: a review

Sleep problems are very common among psychiatric patients. Borderline personality disorder, as a common and severe mental disorder, is associated with different types of sleep disturbances, such as disturbances of sleep continuity, altered REM sleep regulation and nightmares. These disturbances are the result of interaction of the personality traits, concomitant and comorbid diseases and environmental factors. Despite the high prevalence of sleep related disorders in BPD patients, this aspect of BPD is still neglected in clinical and research settings. To date there has been little agreement on sleep characteristics of BPD among different studies, and presence of some uncontrolled confounding factors, make interpretation of the results difficult. However, it seems that appropriate diagnosis and treatment of sleep disorders in BPD patients might lead to better outcome. This article aimed to review the current literature of sleep studies in BPD. Some recommendations and suggestions were made for future researches in this field.

Sleep and dreaming in patients with borderline personality disorder: a polysomnographic study

Previous research has demonstrated disturbances in sleep continuity in subjects with borderline personality disorders (BPD). Moreover, depression-like sleep abnormalities like reduced REM latency have been found in BPD subjects, even without comorbid major depression disorder. Yet it is still unknown what the effect is of co-morbid posttraumatic stress disorder on sleep continuity and dream content in BPD patients group. The present study compared 27 unmedicated female BPD subjects and healthy controls. The patients exhibited increased sleep fragmentation, increased REM density, and reduced REM latency. The findings were independent from co-morbid posttraumatic stress response (PTSD), which was present in 33% of the patient sample. Negatively toned dreams obtained by REM awakenings and nightmares were also reported more often by the patients-also irrespective of co-morbid PTSD-whereas dreams of specific BPD behavior, like self-mutilation, were rare. Taking these finding into account, one might productively investigate whether the sleep abnormalities improve during successful treatment of BPD and whether efficient methods for treating nightmares can be beneficial for this patient group.

The effects of music relaxation and muscle relaxation techniques on sleep quality and emotional measures among individuals with posttraumatic stress disorder

Posttraumatic stress disorder (PTSD), an anxiety disorder with lifetime prevalence of 7.8%, is characterized by symptoms that develop following exposure to traumatic life events and that cause an immediate experience of intense fear, helplessness or horror. PTSD is marked by recurrent nightmares typified by the recall of intrusive experiences and by extended disturbance throughout sleep. Individuals with PTSD respond poorly to drug treatments for insomnia. The disadvantages of drug treatment for insomnia underline the importance of non-pharmacological alternatives. Thus, the present study had three aims: first, to compare the efficiency of two relaxation techniques (muscular relaxation and progressive music relaxation) in alleviating insomnia among individuals with PTSD using both objective and subjective measures of sleep quality; second, to examine whether these two techniques have different effects on psychological indicators of PTSD, such as depression and anxiety; and finally, to examine how initial PTSD symptom severity and baseline emotional measures are related to the efficiency of these two relaxation methods. Thirteen PTSD patients with no other major psychiatric or neurological disorders participated in the study. The study comprised one seven-day running-in, no-treatment period, followed by two seven-day experimental periods. The treatments constituted either music relaxation or muscle relaxation techniques at desired bedtime. These treatments were randomly assigned. During each of these three experimental periods, subjects' sleep was continuously monitored with a wrist actigraph (Ambulatory Monitoring, Inc.), and subjects were asked to fill out several questionnaires concerned with a wide spectrum of issues, such as sleep, depression, and anxiety. Analyses revealed a significant increase in objective and subjective sleep efficiency and a significant reduction in depression level following music relaxation. Moreover, following music relaxation, a highly significant negative correlation was found between improvement in objective sleep efficiency and reduction in depression scale. The study's findings provide evidence that music relaxation at bedtime can be used as treatment for insomnia among individuals with PTSD.

Frequent nightmares in children: familial aggregation and associations with parent-reported behavioral and mood problems

STUDY OBJECTIVES

To conduct a systematic investigation on the prevalence, correlates, and familial aggregation of frequent nightmares in children, and to scrutinize the associations between frequent nightmares and parent-reported behavioral and mood problems in children.

DESIGN

A cross-sectional study was conducted by collecting the data on sociodemographic, sleep, behavioral, and family-related information from a total of 6359 children (age: mean [SD]=9.2 [1.8] years; girls: 49.9%) and their reported biological parents.

SETTING

Community.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Prevalence of frequent nightmares with a criterion of at least once per week was 5.2%. Multinomial regression analysis indicated that monthly family income, paternal and maternal nightmares, insomnia symptoms, parasomniac symptoms, and daytime consequences were significantly associated with nightmares in children. Frequent nightmares in children were significantly associated with hyper-activity (odds ratio [OR]=1.68, 95% CI 1.16-2.44), frequent temper outbursts/mood disturbance (OR=1.76, 95%CI 1.27-2.44), and poor academic performance (OR=1.62, 95% CI 1.11-2.36), after controlling for potential confounding factors. Approximately 20% of children with frequent nightmares experienced comorbid frequent insomnia. Comorbid nightmares and insomnia were associated with increased odds of hyperactivity (OR=4.13, 95% CI 2.13-8.00) and frequent temper outbursts/mood disturbance (OR=2.41, 95%CI 1.27-4.60).

CONCLUSIONS

Frequent nightmares in children are associated with a constellation of child-, sleep-, and family-related factors, including comorbid sleep problems, such as insomnia and parasomnia, family economic status, and parental predisposition. Frequent nightmares are independently associated with emotional and behavioral problems in children.

Prevalence and correlates of frequent nightmares: a community-based 2-phase study

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.

Longitudinal study of nightmares in children: stability and effect of emotional symptoms

Nightmares are defined as dreams with strong negative emotions which awaken the dreamer and are common during childhood: cross-sectional data shows the highest prevalence rates between the ages of five and ten. The present longitudinal study was designed to study the stability of nightmares over the course of 2 years. Sleep questionnaires and Strengths and Difficulties Questionnaires were completed by 851 10-years-old children and their parents, separately. In the total sample, nightmares occurred often in 2.5% (parental estimates) to 3.5% (self estimates of the children). The findings indicate that nightmare stability is considerably high, i.e., nightmare occurrence was predicted by the prevalence the year before (in addition to the concurrent amount of emotional symptoms). Children with 'chronic' nightmares showed more psychopathological symptoms. It would be interesting to follow-up these children in order to investigate whether childhood nightmares are also predictive for adult psychopathology.

Unusual sleep experiences, dissociation, and schizotypy: Evidence for a common domain

This paper reviews studies that have examined associations between unusual sleep experiences (including nightmares, vivid dreaming, narcolepsy symptoms, and complex nighttime behaviors) and dissociation and schizotypy. Using correlational studies and structural analyses, evidence is provided that unusual sleep experiences, dissociation, and schizotypy belong to a common domain. It is demonstrated that unusual sleep experiences show specificity to dissociation and schizotypy compared to other daytime symptoms (e.g., anxiety, depression, substance use) and other sleep disturbances (e.g., insomnia, lassitude/fatigue). The paper also outlines the methodological limitations of the existing evidence and makes suggestions for future research. Finally, three models for the overlap of daytime and nighttime symptoms are reviewed, including biological abnormalities, trauma, and personality traits. Although further research is needed, it is suggested that daytime and nighttime symptoms result from problems with sleep-wake state boundaries, which may be precipitated by stress or trauma. In addition, association between daytime and nighttime symptoms can be attributed to the higher order personality trait of Oddity.

Dream Anxiety Disorders (Nightmares): A Review

Knowledge of the aetiology, epidemiology and treatment of nightmares has improved with more accurate definition of the problem. This review summarizes what is known about nightmares and their relationship with other medical and psychiatric disorders. Treatment methods are discussed, with particular reference to behavioural methods, which have become increasingly popular in recent years. Further research is suggested in order to determine the most efficient method of treating distressing nightmares.

Nightmares: A new neurocognitive model

Nightmares are a prevalent parasomnia associated with a range of psychiatric conditions and pathological symptoms. Current knowledge about how nightmares are produced is still influenced by neo-psychoanalytic speculations as well as by more recent personality, evolutionary and neurobiological models. A majority of these models stipulate some type of emotionally adaptive function for dreaming, e.g., image contextualization, affect desomatization, mood regulation or fear extinction. Nightmares are widely seen to be either an intensified expression of an emotionally adaptive function or, conversely, as evidence of its breakdown. Our recent, affective network dysfunction (AND) model, integrates the tenets of many prior models in proposing that nightmares reflect problems with the fear extinction function of dreaming. This new model accounts for a wide range of dysphoric dream imagery (bad dreams, idiopathic nightmares, post-traumatic nightmares) and incorporates recent findings in the areas of brain imaging, sleep physiology, PTSD, anxiety disorders and the consolidation and extinction of fear memories.

Anxiety and hostility in the manifest dreams of schizophrenic patients

Aside from delusions, hallucinations, and thought disorders, affective disturbances belong to the most prominent symptoms of the schizophrenic process. However, nearly no empirical work has been done on the systematic investigation of the dream affects of patients with schizophrenia. We compared 96 dreams of 19 patients with schizophrenia and an equal number of dreams of 19 healthy controls collected over an 8-week period by means of the Gottschalk-Gleser Analysis Scales. Additionally, central psychopathological syndromes were measured by means of the AMDP-scales each day a patient reported a dream. Although cluster analyses showed general similarities in the organization of dream affects in the two groups, we found differences between patient and control groups in the frequency and intensity of anxious and hostile affects. As in delusions of persecution, patients experience themselves in their dreams more frequently as victims of hostility from outside, which corresponds well with a significantly higher intensity of threat anxieties (death, mutilation). On the other hand, value anxieties (guilt and separation) are found less frequently in the dreams of patients with schizophrenia pointing, together with a less differentiated organization of the dream affects, to the typical affective flattening of residual syndromes.

Nightmares: familial aggregation and association with psychiatric disorders in a nationwide twin cohort

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.

Nightmares and schizotypy

In order to explore the proposed relationship between nightmare occurrence and schizotypy, 30 frequent-nightmare subjects (at least one occurrence per week) and 30 low-nightmare controls, all of whom were female college students, were compared on several converging measures of schizotypal signs and behaviors. Consistent with previous research, frequent nightmare subjects demonstrated greater deviance on psychometric scales of schizotypy, and reported significantly greater schizotypal symptomatology on a structured clinical interview, than controls did. In addition, nightmare subjects produced similar electrodermal habituation patterns to auditory orienting stimuli as those that have been documented in schizophrenia-spectrum disorders. The results suggest that nightmare experience may be a useful conjoint behavioral indicator for the early detection of schizophrenia-spectrum psychopathology.

Nightmares in psychiatry

Nightmares are frightening dreams awakening the dreamer. In psychiatry they are often considered as an indication of psychopathology or even as a feature of schizophrenia. Assumptions are made that nightmares occur more often in psychiatric patients than in the normal population and that they are accompanied by an elevated anxiety level in the daytime. From a psychophysiological point of view nightmares possibly are derailed attemps of problem solving, of overcoming frightening experiences. In this review the importance of nightmares as symptom in psychiatry is assessed. It appears that they are no indication of an elevated anxiety level in the day-time or of psychopathology in general, and they are no criterium for the diagnosis of schizophrenia either.

Relations among nightmare frequency and ego strength, death anxiety, and sex of college students

The present study was designed to investigate empirically the relationship between self-reports of nightmare frequency and ego strength and death anxiety in both men and women. In addition, the interrelations among these variables were assessed. 20 undergraduates with high frequencies of nightmares and 20 with low frequencies (10 men and 10 women per group) were administered the Barron Ego Strength Scale and a death anxiety scale. Significant differences were found between nightmare groups on the Barron scale for men and women but none on the death anxiety scale either by nightmare frequency or sex. A significant negative correlation of -.47 between death anxiety and ego strength was found for women and in one high frequency group. Women with high frequencies of nightmares showed the highest correlation, -.83. These data suggest that nightmare frequency may be a mediating factor in the relationship between ego strength, death anxiety, and sex of subject.

Predisposition for nightmares: a study of hypnotic ability, vividness of imagery, and absorption

The relationships of nightmare frequency to hypnotic ability, vividness of visual imagery, and the tendency to become absorbed in fantasy-like experiences were examined. Subjects were 841 undergraduate university students who participated in group tests of hypnotic ability, after which they estimated the number of nightmares that they had experienced in the prior year. In addition, 406 of the subjects completed Marks' Vividness of Visual Imagery Questionnaire, and Rotenberg and Bowers' Absorption scale. Of the subjects, 76% reported experiencing at least one nightmare in the prior year; 8.3% indicated one or more per month. Individuals with frequent nightmares scored higher on hypnotizability, vividness of visual imagery, and absorption.

Validity of the MMPI narcissistic personality disorder scale

The MMPI Narcissistic Personality Disorder Scale, the Tennessee Self-concept Scale, and a Profile Questionnaire were administered to 100 undergraduate students in the Los Angeles area. The MMPI scale significantly differentiated between people on the Tennessee Self-concept Scale, involvement in a satisfying love relationship, and frequency of nightmares. These findings are consistent with the theories of Kohut and Kernberg.