Nightmare Recall Research Articles

0662 Digital sleep-health surveillance: Population nightmare frequency is observable in social media

Abstract Introduction Nightmares are a critical component of multidimensional sleep health. Frequent nightmare recallers suffer reduced sleep length, depressed mood, and are more likely to be diagnosed with a psychiatric disorder in the future. Reliable population estimates of nightmare frequency are difficult to obtain and often restricted to rigid timepoints (e.g., once per year). Thus, there is a need for low-cost methods to track population levels of nightmare frequency and their dynamic changes over time. In the current study, we tracked dream content and nightmare frequency using a popular new approach – digital health surveillance – that analyzes language of public and freely-accessible social media posts to track population characteristics. Methods To evaluate whether social media could detect known changes in population sleep health, we extracted posts from r/Dreaming, a popular subreddit dedicated to dream sharing. Prior survey studies have shown a reliable increase in nightmare frequency during the first wave of the COVID-19 pandemic. Thus, we quantified the amount of nightmares posted on Reddit surrounding the World Health Organization’s (WHO) declaration of a COVID-19 as a global pandemic. Nightmares were identified using a word-search algorithm that identified nightmare-related words in a post title. Nightmare frequency was compared before and after the WHO declaration using a chi-squared analysis. Results The percentage of dreams posted on Reddit that were identified as nightmares was higher after the WHO declaration than before (p < .05). Additionally, the amount of anxiety in all dreams posted on Reddit was higher after the WHO declaration than before (p < .05). Weekly change in dream anxiety was positively correlated with the percentage of COVID-19 news headlines (p < .05). Conclusion We observed an increase in nightmares shared on Reddit immediately following the WHO’s declaration of COVID-19 as a global pandemic. This novel approach to tracking nightmares might offer the field of sleep medicine a low-cost and real-time system for monitoring population sleep health. Other recent work suggests this method might be viable for tracking other components of sleep health. Support (if any)

Altered parasympathetic activity during sleep and emotionally arousing wakefulness in frequent nightmare recallers

Nightmare disorder is characterized by dysfunctional emotion regulation and poor subjective sleep quality reflected in pathophysiological features such as abnormal arousal processes and sympathetic influences. Dysfunctional parasympathetic regulation, especially before and during rapid eye movement (REM) phases, is assumed to alter heart rate (HR) and its variability (HRV) of frequent nightmare recallers (NM). We hypothesized that cardiac variability is attenuated in NMs as opposed to healthy controls (CTL) during sleep, pre-sleep wakefulness and under an emotion-evoking picture-rating task. Based on the polysomnographic recordings of 24 NM and 30 CTL participants, we examined HRV during pre-REM, REM, post-REM and slow wave sleep, separately. Additionally, electrocardiographic recordings of resting state before sleep onset and under an emotionally challenging picture-rating task were also analyzed. Applying repeated measures analysis of variance (rmANOVA), a significant difference was found in the HR of NMs and CTLs during nocturnal segments but not during resting wakefulness, suggesting autonomic dysregulation, specifically during sleep in NMs. As opposed to the HR, the HRV values were not significantly different in the rmANOVA in the two groups, implying that the extent of parasympathetic dysregulation on a trait level might depend on the severeness of dysphoric dreaming. Nonetheless, in the group comparisons, the NM group showed increased HR and reduced HRV during the emotion-evoking picture-rating task, which aimed to model the nightmare experience in the daytime, indicating disrupted emotion regulation in NMs under acute distress. In conclusion, trait-like autonomic changes during sleep and state-like autonomic responses to emotion-evoking pictures indicate parasympathetic dysregulation in NMs.

Lucid dreaming increased during the COVID-19 pandemic: An online survey.

The COVID-19 pandemic changed people’s lives all over the world. While anxiety and stress decreased sleep quality for most people, an increase in total sleep time was also observed in certain cohorts. Dream recall frequency also increased, especially for nightmares. However, to date, there are no consistent reports focusing on pandemic-related changes in lucid dreaming, a state during which dreamers become conscious of being in a dream as it unfolds. Here we investigated lucid dreaming recall frequency and other sleep variables in 1,857 Brazilian subjects, using an online questionnaire. Firstly, we found that most participants (64.78%) maintained their lucid dream recall frequency during the pandemic, but a considerable fraction (22.62%) informed that lucid dreams became more frequent, whereas a smaller subset (12.60%) reported a decrease in these events during the pandemic. Secondly, the number of participants reporting lucid dreams at least once per week increased during the pandemic. Using a mixed logistic regression model, we confirmed that the pandemic significantly enhanced the recall frequency of lucid dreams (p = 0.002). Such increase in lucid dreaming during the pandemic was significantly associated with an enhancement in both dream and nightmare recall frequencies, as well as with sleep quality and symptoms of REM sleep behavior disorder. Pandemic-related increases in stress, anxiety, sleep fragmentation, and sleep extension, which enhance REM sleep awakening, may be associated with the increase in the occurrence of lucid dreams, dreams in general, and nightmares.

The autonomic activity of nightmare sufferers during sleep and emotion-evoking picture viewing

IntroductionIn nightmare disorder, dysfunctional emotion regulation goes along with poor subjective sleep quality, which is characterised by pathophysiological features such as abnormal arousal processes and sympathetic influences. Dysfunctional parasympathetic regulation, especially before and during REM phases, is assumed to alter heart rate (HR) and its variability (HRV) of frequent nightmare recallers.ObjectivesWe hypothesised that cardiac variability is attenuated in participants experiencing frequent nightmares as opposed to healthy control subjects during less deep sleep stages and an emotion-evoking picture-rating task.MethodsBased on the second-nights’ polysomnographic recordings of 24 nightmare disordered (NM) and 30 control (CTL) subjects, we examined HRV during pre-REM, REM, post-REM and slow wave sleep periods, separately. Additionally, ECG recordings of wakeful periods such as resting state before sleep onset and an emotional picture-rating task were also analysed.ResultsAccording to our results, a significant difference was found in the HR of the NM and CTL groups in the nocturnal segments but not during resting wakefulness before sleep onset, suggesting autonomic dysregulation, specifically during sleep in nightmare disorder. However, despite the accelerated HR of NM subjects at night, they did not exhibit lower HRV. Regarding the emotional task, we also found a contrast between the NM and CTL subjects’ HR and HRV, which might indicate altered processes of emotion regulation in nightmare disorder, but the two groups’ subjective picture ratings did not differ.ConclusionsIn summary, our study suggests that there might be some trait-like autonomic changes during sleep, but also state-like autonomic responses to emotion-evoking pictures in nightmare disorder.DisclosureNo significant relationships.

Stuck in a lockdown: Dreams, bad dreams, nightmares, and their relationship to stress, depression and anxiety during the COVID-19 pandemic.

An upsurge in dream and nightmare frequency has been noted since the beginning of the COVID-19 pandemic and research shows increases in levels of stress, depression and anxiety during this time. Growing evidence suggests that dream content has a bi-directional relationship with psychopathology, and that dreams react to new, personally significant and emotional experiences. The first lockdown experience was an acute event, characterized by a combination of several unprecedent factors (new pandemic, threat of disease, global uncertainty, the experience of social isolation and exposure to stressful information) that resulted in a large-scale disruption of life routines. This study aimed at investigating changes in dream, bad dream and nightmare recall; most prevalent dream themes; and the relationship between dreams, bad dreams, nightmares and symptoms of stress, depression and anxiety during the first COVID-19 lockdown (April-May 2020) through a national online survey. 968 participants completed an online survey. Dream themes were measured using the Typical Dreams Questionnaire; stress levels were measured by the Cohen's Perceived Stress Scale; symptoms of anxiety were assessed by Generalized Anxiety Disorder (GAD-7) scale; and symptoms of depression were assessed using the Quick Inventory of Depressive Symptomatology. 34% (328) of participants reported increased dream recall during the lockdown. The most common dream themes were centered around the topics of 1) inefficacy (e.g., trying again and again, arriving late), 2) human threat (e.g., being chased, attacked); 3) death; and 4) pandemic imagery (e.g., being separated from loved ones, being sick). Dream, bad dream and nightmare frequency was highest in individuals with moderate to severe stress levels. Frequency of bad dreams, nightmares, and dreams about the pandemic, inefficacy, and death were associated with higher levels of stress, as well as with greater symptoms of depression and anxiety. Results support theories of dream formation, environmental susceptibility and stress reactivity. Dream content during the lockdown broadly reflected existential concerns and was associated with increased symptoms of mental health indices.

Local Neuronal Synchronization in Frequent Nightmare Recallers and Healthy Controls: A Resting-State Functional Magnetic Resonance Imaging Study.

Nightmares are highly dysphoric dreams that are well-remembered upon awakening. Frequent nightmares have been associated with psychopathology and emotional dysregulation, yet their neural mechanisms remain largely unknown. Our neurocognitive model posits that nightmares reflect dysfunction in a limbic-prefrontal circuit comprising medial prefrontal and anterior cingulate cortices, hippocampus, and amygdala. However, there is a paucity of studies that used brain imaging to directly test the neural correlates of nightmares. One such study compared the regional homogeneity (ReHo) of resting-state functional magnetic resonance imaging blood-oxygen level-dependent signals between frequent nightmare recallers and controls. The main results were greater regional homogeneity in the left anterior cingulate cortex and right inferior parietal lobule for the nightmare recallers than for the controls. In the present study, we aimed to document the ReHo correlates of frequent nightmares using several nightmare severity measures. We acquired resting-state functional magnetic resonance imaging data from 18 frequent nightmare recallers aged 18–35 (3 males and 15 females) and 18 age- and sex-matched controls, as well as retrospective and prospective disturbed dreaming frequency estimates and scores on the Nightmare Distress Questionnaire. While there were inconsistent results for our different analyses (group comparisons, correlational analyses for frequency estimates/Nightmare Distress scores), our results suggest that nightmares are associated with altered ReHo in frontal (medial prefrontal and inferior frontal), parietal, temporal and occipital regions, as well as some subcortical regions (thalamus). We also found a positive correlation between retrospective disturbed dreaming frequency estimates and ReHo values in the hippocampus. These findings are mostly in line with a recent SPECT study from our laboratory. Our results point to the possibility that a variety of regions, including but not limited to the limbic-prefrontal circuit of our neurocognitive model, contribute to nightmare formation.

Long-term effects of treatment for chronic nightmares: is imagery rehearsal therapy robust in the COVID-19 pandemic?

Citation:Sierro C, Leslie W, Putois B. Long-term effects of treatment for chronic nightmares: is imagery rehearsal therapy robust in the COVID-19 pandemic? J Clin Sleep Med. 2020;16(11):1993.

Methodological Recommendations to Control for Factors Influencing Dream and Nightmare Recall in Clinical and Experimental Studies of Dreaming.

In order to ensure robust relationships between the dependent and independent variables in clinical dream/nightmare studies, the major factors which influence the frequency of reported dreams must be controlled. This article sets out methodological recommendations to both researchers seeking to ensure the equivalence of experimental groups of participants in group-matching designs, and to clinicians who wish to check that any change in frequency of reported nightmares over the course of a psychological or a pharmacological intervention is not caused by factors other than the experimental treatment itself. The main factors influencing the frequency of dream recall are presented: demographic variables, psychological characteristics, pathological dimensions, and substance consumption. A series of questionnaires is proposed for easily measuring these control variables.

Unaltered EEG spectral power and functional connectivity in REM microstates in frequent nightmare recallers: are nightmares really a REM parasomnia?

BackgroundFrequent nightmares show signs of hyperarousal in NREM sleep. Nevertheless, idiopathic nightmare disorder is considered a REM parasomnia, but the pathophysiology of REM sleep in relation to frequent nightmares is controversial. Cortical oscillatory activity in REM sleep is largely modulated by phasic and tonic REM periods and seems to be linked to different functions and dysfunctions of REM sleep. Here, we examined cortical activity and functional synchronization in frequent nightmare recallers and healthy controls, during phasic and tonic REM. MethodsFrequent nightmare recallers (N = 22) and healthy controls (N = 22) matched for high dream recall spent two nights in the laboratory. Phasic and tonic REM periods from the second nights' recordings were selected to examine differences in EEG spectral power and weighted phase lag index (WPLI) across groups and REM states. ResultsPhasic REM showed increased power and synchronization in delta and gamma frequency bands, whereas tonic REM featured increased power and synchronization in the alpha and beta bands. In the theta band, power was higher during tonic, and synchronization was higher during phasic REM sleep. No differences across nightmare and control participants or patterns representing interactions between the groups and REM microstates emerged. ConclusionsOur findings do not support the idea that abnormal REM sleep power and synchronization play a role in the pathophysiology of frequent nightmares. Altered REM sleep in nightmare disorder could have been confounded with comorbid pathologies and increased dream recall, or might be linked to more specific state factors (nightmare episodes).

0879 Nightmare Recall Rates Correlate with Hyperarousal in Trauma-exposed Individuals

0879 Nightmare Recall Rates Correlate with Hyperarousal in Trauma-exposed Individuals

Nightmare Severity Is Inversely Related to Frontal Brain Activity During Waking State Picture Viewing.

Growing evidence suggests that nightmares have considerable adverse effects on waking behavior, possibly by increasing post-sleep negative emotions. Dysphoric reactions to nightmares are one component of nightmare severity for which the neural correlates are unknown. Here, we investigate possible neural correlates of nightmare severity in a sample of individuals who frequently recall nightmares. Our principal measure of nightmare severity is nightmare distress as indexed by the Nightmare Distress Questionnaire (NDQ), and secondary measures are retrospective and prospective estimates of frequency of recalling dysphoric dreams (DD). We used high-resolution technetium 99m ethyl cysteinate dimer single photon emission computed tomography to assess regional cerebral blood flow (rCBF) while 18 individuals who were frequent nightmare recallers viewed negative and neutral pictures from the International Affective Picture System. We correlated rCBF with NDQ scores and DD recall frequency estimates. Negative correlations were observed between NDQ scores and rCBF during negative picture viewing in bilateral insula and anterior cingulate, right medial frontal gyrus, bilateral superior temporal gyrus, right inferior frontal and precentral gyri, and bilateral putamen. Retrospective DD recall correlated with rCBF activity primarily in regions overlapping those related to NDQ scores. Prospective DD recall was only weakly related to rCBF. Results for the neutral condition overlapped partially with those for the negative condition; in particular, NDQ and retrospective DD recall were related to rCBF in medial prefrontal and anterior cingulate gyri. Results point to a possible overlap in brain mechanisms involved in nightmare dysphoria (during sleep) and distress (during wakefulness) among individuals who frequently recall nightmares. They provide partial support for a neurocognitive model of nightmares. A commentary on this article appears in this issue on page 179.

Sleep spindles are altered in early- but not late-onset nightmare recallers

Nightmares are a common sleep disorder, defined as highly disturbing mentation which usually awakens the individual from rapid eye movement (REM) sleep. While nightmares are mainly a REM sleep phenomenon, Picard-Deland et al., (2017) recently showed an association between nightmare recall and sleep spindles, which are a non-rapid eye movement (NREM) oscillatory feature. Their results pointed to fewer slow spindles and a higher oscillatory frequency for fast spindles among frequent nightmare recallers compared with controls. To test the suggestion that nightmares stem from changes to emotional neural circuits arising in early childhood (Nielsen, 2017), including early changes in sleep spindles (Scholle et al., 2007), we investigated if the spindle features of early-onset nightmare recallers (ie, recalling nightmares since childhood) (N = 22), differed from those of late-onset nightmare recallers (ie, since adolescence or adulthood) (N = 11), or from those of controls (N = 23). A retrospective analysis of the sleep spindles of 56 participants who had undergone a polysomnographically-recorded morning nap revealed that Early starters uniquely exhibited lower slow spindle densities in five of six derivations (all p < 0.045) and higher fast spindle frequencies in all six derivations (all p < 0.015). These results add precision to previously reported findings for Nightmare recallers: spindle differences are shown to hold only for Early starters. The lifelong occurrence of nightmares may be closely tied to disruptions in the normal development of spindle generation processes occurring early in development.

Elevated perseveration errors on a verbal fluency task in frequent nightmare recallers: a replication.

A recent study reported that individuals recalling frequent idiopathic nightmares (NM) produced more perseveration errors on a verbal fluency task than did control participants (CTL), while not differing in overall verbal fluency. Elevated scores on perseveration errors, an index of executive dysfunction, suggest a cognitive inhibitory control deficit in NM participants. The present study sought to replicate these results using a French-speaking cohort and French language verbal fluency tasks. A phonetic verbal fluency task using three stimulus letters (P, R, V) and a semantic verbal fluency task using two stimulus categories (female and male French first names) were administered to 23 participants with frequent recall of NM (≥2 NM per week, meanage=24.4±4.0years), and to 16 CTL participants with few recalled NM (≤1 NM per month, meanage=24.5±3.8years). All participants were French-speaking since birth and self-declared to be in good mental and physical health apart from their NM. As expected, groups did not differ in overall verbal fluency, i.e. total number of correct words produced in response to stimulus letters or categories (P=0.97). Furthermore, groups exhibited a difference in fluency perseveration errors, with the NM group having higher perseveration than the CTL group (P=0.03, Cohen's d=0.745). This replication suggests that frequent NM recallers have executive inhibitory dysfunction during a cognitive association task and supports a neurocognitive model which posits fronto-limbic impairment as a neural correlate of disturbed dreaming.

Sleep spindle and psychopathology characteristics of frequent nightmare recallers

Idiopathic nightmares are a common disturbance of rapid eye movement sleep (REM) sleep, but studies of comorbid pathologies and sleep architecture suggest that non-REM (NREM) sleep is also affected. Sleep spindles are a NREM sleep characteristic associated with both pathophysiology and sleep-dependent memory consolidation, yet they have not been evaluated in frequent nightmare recallers. The morning naps of 38 participants with frequent idiopathic nightmares (mean age: 23.7 ± 3.78 years) and 25 age- and sex-matched controls (23.9 ± 3.65 years) were recorded and their sleep evaluated. A custom spindle detector assessed NREM sleep stage 2 (N2) sleep spindles on six electroencephalogram (EEG) derivations (F3, F4, C3, C4, O1, and O2) for density (number spindles/N2 time), mean frequency, and amplitude. Total spindles (10–16 Hertz (Hz) range), slow spindles (10–12.79 Hz), and fast spindles (12.8–16 Hz) were all assessed separately. Compared with the Control group, the Nightmare group had longer N2 sleep latency and a marginally greater %N2 sleep. The Nightmare group also had a lower than normal density of slow spindles in most EEG derivations, a higher density of fast spindles in frontal derivations, and an elevated fast spindle oscillatory frequency—“faster fast” spindles—mainly in central derivations. These differences withstood controls for pre-existing group differences in depression. Correlational analyses demonstrated a further pattern of group differences by which higher pathology scores were associated with higher slow spindle densities and slower spindle frequencies for the Nightmare but not the Control group. A similar pattern was observed for some dream content measures, ie, the Nightmare group showed positive correlations of slow spindle density with dreamed fear and word count and negative correlations with dreamed positive emotion. Conversely, the Control group showed opposite trends. Results thus demonstrate abnormalities in the composition of N2 sleep—and especially in N2 spindles—among frequent nightmare recallers and link these abnormalities to both trait (psychopathology) and state (dream content) factors. Spindle findings for psychopathology resemble, but are not identical with, previous findings for patients with major depression, social anxiety, and schizophrenia and are thus consistent with an explanation implicating spindles as trait markers of psychopathology. Correlational analyses go beyond a trait explanation to suggest several possible state-based explanations involving memory consolidation mechanisms, specifically, the possibility that spindles index either emotional or verbal task-based processes.

REM Sleep Theta Changes in Frequent Nightmare Recallers.

To replicate and expand upon past research by evaluating sleep and wake electroencephalographic spectral activity in samples of frequent nightmare (NM) recallers and healthy controls. Computation of spectral activity for sleep (non-REM and REM) and wake electroencephalogram recordings from 18 frequent NM recallers and 15 control participants. There was higher "slow-theta" (2-5 Hz) for NM recallers than for controls during wake, non-REM sleep and REM sleep. Differences were clearest for frontal and central derivations and for REM sleep cycles 2-4. There was also higher beta activity during NREM sleep for NM recallers. Findings partially replicate past research by demonstrating higher relative "slow-theta" (3-4Hz) for NM recallers than for controls. Findings are consistent with a neurocognitive model of nightmares that stipulates cross-state anomalies in emotion processing in NM-prone individuals.

NREM sleep spindles are associated with dream recall

Both rapid eye movement (REM) sleep dreaming and non-rapid eye movement (NREM) sleep spindles have been linked to processes of memory consolidation. However, relationships between the two phenomena have yet to be explored. In a heterogeneous sample of 53 healthy subjects who had participated in a memory consolidation protocol and who varied in their self-reported recall of dreams and nightmares, we assessed overnight polysomnography, N2 sleep spindle density, REM dream word count, and retrospective estimates of how often they recall dreams, bad dreams (dysphoric dreams, no awakening), and nightmares (dysphoric dreams, with awakenings). Fast spindle density positively correlated with all measures of dream recall but was most robustly associated with bad dream recall and REM dream word count. Correlations with bad dream recall were particularly strong for spindles occurring in sleep cycles 2 and 3 and correlations with word count for cycles 1, 4, and 5. While slow spindle density showed opposite correlation...

Disturbed dreaming during the third trimester of pregnancy

ObjectiveThe majority of women develop sleep impairments during pregnancy, but alterations in dream experiences remain poorly understood. This study aimed to assess prospectively and comparatively the recall of dreaming and of disturbed dreaming in late pregnancy. MethodsFifty-seven nulliparous, third-trimester pregnant women (mean age±SD, 28.7±4.06years) and 59 non-pregnant controls (mean age±SD, 26.8±4.21years) completed demographics and psychological questionnaires. A 14-day prospective home log assessed sleep and dream characteristics and the Sleep Disorders Questionnaire measured retrospective dream and disturbed dream recall. ResultsEven though pregnant and non-pregnant women showed similar prospective dream recall (P=0.47), pregnant women reported prospectively more bad dreams (P=0.004). More pregnant women (21%) than non-pregnant women (7%) reported a nightmare incidence exceeding moderately severe pathology (>1/week) (P=0.03). Pregnant women also reported overall lower sleep quality (P=0.007) and more night awakenings (P=0.003). Higher prospective recall of bad dreams (r=−0.40, P=0.002) and nightmares (r=−0.32, P=0.001) both correlated with lower sleep quality in pregnant women. ConclusionsLate pregnancy is a period of markedly increased dysphoric dream imagery that may be a major contributor to impaired sleep at this time. Further polysomnographic assessments of pregnant women are needed to clarify relationships between sleep and disturbed dream production in this population.

What physicians need to know about dreams and dreaming

An overview of the current status of dream science is given, designed to provide a basic background of this field for the sleep-interested physician. No cognitive state has been more extensively studied and is yet more misunderstood than dreaming. Much older work is methodologically limited by lack of definitions, small sample size, and constraints of theoretical perspective, with evidence equivocal as to whether any special relationship exists between rapid eye movement (REM) sleep and dreaming. As the relationship between dreams and REM sleep is so poorly defined, evidence-based studies of dreaming require a dream report. The different aspects of dreaming that can be studied include dream and nightmare recall frequency, dream content, dreaming effect on waking behaviors, dream/nightmare associated medications, and pathophysiology affecting dreaming. Whether studied from behavioral, neuroanatomical, neurochemical, pathophysiological or electrophysiological perspectives, dreaming reveals itself to be a complex cognitive state affected by a wide variety of medical, psychological, sleep and social variables.

The Nightmares of Sleep Apnea: Nightmare Frequency Declines with Increasing Apnea Hypopnea Index

To clarify the association of reported nightmare recall with polysomnographically defined obstructive sleep apnea (OSA) in a sleep laboratory population. This study included 393 individuals undergoing clinical polysomnography including a general intake questionnaire with questions on dream and nightmare recall frequency. Mean age was 50.5 and a range of 13 to 82 years, with 33% of the sample female and 67% male. Reported dream and nightmare recall were classified as infrequent when reported at less than once a month, or frequent when reported at a frequency greater than once per week. Mean Apnea-hypopnea Index AHI was 34.9 (std. 32.0) indicating a high frequency of severe (AHI > 30) OSA in this clinical study population. Both AHI and Apnea Index (AI) were significantly higher (p = 0.000) for the grouping reporting infrequent nightmare recall. As the AHI score increased, the percent of participants with frequent nightmare recall decreased linearly. Patients with higher AHI report a lower nightmare frequency, indicating that significant OSA suppresses the cognitive experience of nightmare recall. Depressed nightmare recall may occur secondary to the REMS suppression know to occur in patients with significant OSA.

Dream-associated Behaviors Affecting Pregnant and Postpartum Women

Evaluate the prevalence and phenomenology of dream-associated behaviors affecting pregnant and postpartum mothers. Episodes consist of anxious dreams and nightmares about the new infant that are accompanied by complex behaviors (motor activity, speaking, expressing emotion). Three-group design (postpartum, pregnant, null gravida), self-report, and repeated measures. Pregnancy and postpartum groups: completion of questionnaires in hospital room within 48 hours of giving birth and home telephone interviews; null gravida group: completion of questionnaires and interview in person or by telephone. Two hundred seventy-three women in 3 groups: postpartum: n = 202 (mean age = 29.7 +/- 4.94 years; 95 primiparas, 107 multiparas); pregnant: n = 50 (mean age = 31.1 +/- 5.44 years); null gravida: n = 21 (mean age = 28.5 +/- 6.34 years). Subjects completed questionnaires about pregnancy and birth factors, personality, and sleep and participated in interviews concerning the prevalence of recent infant dreams and nightmares, associated behaviors, anxiety, depression, and other psychopathologic factors. Most women in all groups recalled dreams (88%-91%). Postpartum and pregnant women recalled infant dreams and nightmares with equal prevalence, but more postpartum women reported they contained anxiety (75%) and the infant in peril (73%) than did pregnant women (59%, P < 0.05 and 42%, P < 0.0001). More postpartum (63%) than pregnant (40%) women reported dream-associated behaviors (P < 0.01), but neither group differed from null gravida women (56%). This was due to different distributions over groups of the behavior subtypes. Motor activity was present in twice as many postpartum (57%) as pregnant (24%) or null gravida (25%) women (all P < 0.0001). Expressing emotion was more prevalent among null gravida (56%) than postpartum women (27%) (P < 0.05) but was not different from pregnant women (37%). Speaking was equally prevalent among the 3 groups (12%-19%). Behaviors were associated with nightmares, dream anxiety and, among postpartum women, post-awakening anxiety (41%), confusion (51%), and a need to check on the infant (60%). Primiparas and multiparas differed in dream and nightmare recall but not in prevalence of dream-associated behaviors. The prevalent occurrence of pregnancy and postpartum infant dreams and associated behaviors may reflect the pervasive emotional influence of maternal concerns or changes instigated by severe sleep disruption, rapid eye movement sleep deprivation, and altered hormone levels.