Nightmares in People with COVID-19: Did Coronavirus Infect Our Dreams?

The relationships between insomnia, nightmares, and dreams: A systematic review

Insomnia and nightmares are both prevalent and debilitating sleep difficulties. The present systematic review aims to document the relationships between insomnia and nightmares in individuals without a concomitant psychopathology. The relationships between insomnia and dreams are also addressed. PsycINFO and Medline were searched for papers published in English or French from 1970 to March 2023. Sixty-seven articles were included for review. Most results support positive relationships between insomnia variables and nightmare variables in individuals with insomnia, individuals with nightmares, the general population, students, children and older adults, and military personnel and veterans. These positive relationships were also apparent in the context of the COVID-19 pandemic. Some psychological interventions, such as Imagery Rehearsal Therapy, might be effective in alleviating both nightmares and insomnia symptoms. Regarding the relationships between insomnia and dreams, compared with controls, the dreams of individuals with insomnia are characterized by more negative contents and affects. The results show that insomnia and nightmares are connected and may be mutually aggravating. A model is proposed to explain how insomnia might increase the likelihood of experiencing nightmares, and how nightmares can in turn lead to sleep loss and nonrestorative sleep.

How COVID-19 Affected Sleep Talking Episodes, Sleep and Dreams?

BACKGROUND

The COVID-19 pandemic increased symptoms of stress and anxiety and induced changes in sleep quality, dream activity, and parasomnia episodes. It has been shown that stressful factors and/or bad sleep habits can affect parasomnia behaviors. However, investigations on how COVID-19 has affected sleep, dreams, and episode frequency in parasomnias are rare. The current study focuses on the impact of the pandemic on a specific parasomnia characterized by speech production (sleep talking, ST).

METHODS

We selected 27 participants with frequent ST episodes (STs) during the pandemic and compared them with 27 participants with frequent STs from a previous study conducted during a pre-pandemic period. All participants performed home monitoring through sleep logs and recorded their nocturnal STs for one week.

RESULTS

We observed a higher frequency of STs in the pandemic group. Moreover, STs were related to the emotional intensity of dreams, independent of the pandemic condition. The pandemic was associated with lower bizarreness of dreams in the pandemic group. There were no differences in sleep variables between the two groups.

CONCLUSION

Overall, these results suggest a stressful effect of COVID-19 on the frequency of STs. Both the pandemic and the frequency of STs affect qualitative characteristics of dreams in this population.

The Aftermath of COVID-19: Exploring the Long-Term Effects on Organ Systems

BACKGROUND

Post-acute sequelae of SARS-CoV-2 infection (PASC) is a complicated disease that affects millions of people all over the world. Previous studies have shown that PASC impacts 10% of SARS-CoV-2 infected patients of which 50-70% are hospitalised. It has also been shown that 10-12% of those vaccinated against COVID-19 were affected by PASC and its complications. The severity and the later development of PASC symptoms are positively associated with the early intensity of the infection.

RESULTS

The generated health complications caused by PASC involve a vast variety of organ systems. Patients affected by PASC have been diagnosed with neuropsychiatric and neurological symptoms. The cardiovascular system also has been involved and several diseases such as myocarditis, pericarditis, and coronary artery diseases were reported. Chronic hematological problems such as thrombotic endothelialitis and hypercoagulability were described as conditions that could increase the risk of clotting disorders and coagulopathy in PASC patients. Chest pain, breathlessness, and cough in PASC patients were associated with the respiratory system in long-COVID causing respiratory distress syndrome. The observed immune complications were notable, involving several diseases. The renal system also was impacted, which resulted in raising the risk of diseases such as thrombotic issues, fibrosis, and sepsis. Endocrine gland malfunction can lead to diabetes, thyroiditis, and male infertility. Symptoms such as diarrhea, nausea, loss of appetite, and taste were also among reported observations due to several gastrointestinal disorders. Skin abnormalities might be an indication of infection and long-term implications such as persistent cutaneous complaints linked to PASC.

CONCLUSIONS

Long-COVID is a multidimensional syndrome with considerable public health implications, affecting several physiological systems and demanding thorough medical therapy, and more study to address its underlying causes and long-term effects is needed.

Viral simulations in dreams: The effect of the COVID-19 pandemic on threatening dream content in a Finnish sample of diary dreams

Previous research indicates that the COVID-19 pandemic has affected dreaming negatively. We compared 1132 dreams collected with prospective two-week dream diary during the pandemic to 166 dreams collected before the pandemic. We hypothesized that the pandemic would increase the number of threatening events, threats related to diseases, and the severity of threats. We also hypothesized that dreams that include direct references to the pandemic will include more threatening events, more disease-related threats, and more severe threats. In contradiction with our hypotheses, results showed no differences between pandemic and pre-pandemic samples in the number of threats, threats related to diseases, or severe threats. However, dreams with direct references to the pandemic had more threats, disease-related threats, and severe threats. Our results thus do not suggest a significant overall increase in nightmarish or threatening dream content during the pandemic but show a more profound effect on a minority of dreams.

Parasomnias During the COVID-19 Pandemic

COVID-19 had a massive impact on sleep, resulting in overall increase of sleep disturbances. During lockdown many factors contributed to sleep disturbances, in particular changes in sleep-wake habits and stress. This article will describe the frequency and features of the principal parasomnias and the impact of the pandemic and the government restriction measures on sleep. Among different pathophysiological hypotheses, we will discuss the role of stress, considered as an expression of the allostatic load. Finally, during the pandemic, parasomnias were mainly investigated by questionnaires, with controversial results; video-polysomnographic studies are crucial to obtain a definitive diagnosis, even in critical conditions.

Nightmare frequency is a risk factor for suicidal ideation during the COVID-19 pandemic

The association between nightmare frequency (NMF) and suicidal ideation (SI) is well known, yet the impact of the COVID-19 pandemic on this relation is inconsistent. This study aimed to investigate changes in NMF, SI, and their association during the COVID-19 pandemic. Data were collected in 16 countries using a harmonised questionnaire. The sample included 9328 individuals (4848 women; age M[SD] = 46.85 [17.75] years), and 17.60% reported previous COVID-19. Overall, SI was significantly 2% lower during the pandemic vs. before, and this was consistent across genders and ages. Most countries/regions demonstrated decreases in SI during this pandemic, with Austria (-9.57%), Sweden (-6.18%), and Bulgaria (-5.14%) exhibiting significant declines in SI, but Italy (1.45%) and Portugal (2.45%) demonstrated non-significant increases. Suicidal ideation was more common in participants with long-COVID (21.10%) vs. short-COVID (12.40%), though SI did not vary by COVID-19 history. Nightmare frequency increased by 4.50% during the pandemic and was significantly higher in those with previous COVID-19 (14.50% vs. 10.70%), during infection (23.00% vs. 8.10%), and in those with long-COVID (18.00% vs. 8.50%). The relation between NMF and SI was not significantly stronger during the pandemic than prior (rs = 0.18 vs. 0.14; z = 2.80). Frequent nightmares during the pandemic increased the likelihood of reporting SI (OR = 1.57, 95% CI 1.20-2.05), while frequent dream recall during the pandemic served a protective effect (OR = 0.74, 95% CI 0.59-0.94). These findings have important implications for identifying those at risk of suicide and may offer a potential pathway for suicide prevention.

Associations between changes in habitual sleep duration and lower self-rated health among COVID-19 survivors: findings from a survey across 16 countries/regions

BACKGROUND

Self-rated health (SRH) is widely recognized as a clinically significant predictor of subsequent mortality risk. Although COVID-19 may impair SRH, this relationship has not been extensively examined. The present study aimed to examine the correlation between habitual sleep duration, changes in sleep duration after infection, and SRH in subjects who have experienced SARS-CoV-2 infection.

METHODS

Participants from 16 countries participated in the International COVID Sleep Study-II (ICOSS-II) online survey in 2021. A total of 10,794 of these participants were included in the analysis, including 1,509 COVID-19 individuals (who reported that they had tested positive for COVID-19). SRH was evaluated using a 0-100 linear visual analog scale. Habitual sleep durations of < 6 h and > 9 h were defined as short and long habitual sleep duration, respectively. Changes in habitual sleep duration after infection of ≤ -2 h and ≥ 1 h were defined as decreased or increased, respectively.

RESULTS

Participants with COVID-19 had lower SRH scores than non-infected participants, and those with more severe COVID-19 had a tendency towards even lower SRH scores. In a multivariate regression analysis of participants who had experienced COVID-19, both decreased and increased habitual sleep duration after infection were significantly associated with lower SRH after controlling for sleep quality (β = -0.056 and -0.058, respectively, both p < 0.05); however, associations between current short or long habitual sleep duration and SRH were negligible. Multinomial logistic regression analysis showed that decreased habitual sleep duration was significantly related to increased fatigue (odds ratio [OR] = 1.824, p < 0.01), shortness of breath (OR = 1.725, p < 0.05), diarrhea/nausea/vomiting (OR = 2.636, p < 0.01), and hallucinations (OR = 5.091, p < 0.05), while increased habitual sleep duration was significantly related to increased fatigue (OR = 1.900, p < 0.01).

CONCLUSIONS

Changes in habitual sleep duration following SARS-CoV-2 infection were associated with lower SRH. Decreased or increased habitual sleep duration might have a bidirectional relation with post-COVID-19 symptoms. Further research is needed to better understand the mechanisms underlying these relationships for in order to improve SRH in individuals with COVID-19.

Long COVID, the Brain, Nerves, and Cognitive Function

SARS-CoV-2, a single-stranded RNA coronavirus, causes an illness known as coronavirus disease 2019 (COVID-19). Long-term complications are an increasing issue in patients who have been infected with COVID-19 and may be a result of viral-associated systemic and central nervous system inflammation or may arise from a virus-induced hypercoagulable state. COVID-19 may incite changes in brain function with a wide range of lingering symptoms. Patients often experience fatigue and may note brain fog, sensorimotor symptoms, and sleep disturbances. Prolonged neurological and neuropsychiatric symptoms are prevalent and can interfere substantially in everyday life, leading to a massive public health concern. The mechanistic pathways by which SARS-CoV-2 infection causes neurological sequelae are an important subject of ongoing research. Inflammation- induced blood-brain barrier permeability or viral neuro-invasion and direct nerve damage may be involved. Though the mechanisms are uncertain, the resulting symptoms have been documented from numerous patient reports and studies. This review examines the constellation and spectrum of nervous system symptoms seen in long COVID and incorporates information on the prevalence of these symptoms, contributing factors, and typical course. Although treatment options are generally lacking, potential therapeutic approaches for alleviating symptoms and improving quality of life are explored.

Longitudinal Findings on the Oneiric Activity Changes Across the Pandemic

Purpose

COVID-19 pandemic waves have strongly influenced individuals' behaviors and mental health. Here, we analyzed longitudinal data collected in the Spring 2020 and 2021 from a large Italian sample with the aim of assessing changes in dream features between the first and third wave. Specifically, we evaluated the modifications of pandemic dream activity as a function of the general distress variations over time. Also, we detected the best explanatory variables of nightmare frequency and distress.

Materials and Methods

Participants previously involved in the web survey during the first wave of the pandemic were asked to complete a new online survey on sleep and dream features available in Spring 2021 (N=728). Subjects decreasing their level of psychological general distress in the third (T3) vs the first (T1) pandemic wave were defined as "Improved" (N=330). In contrast, participants with an unchanged or increased level of general distress were defined as "Not Improved" (N=398).

Results

Statistical comparisons revealed that dream recall frequency, nightmare frequency, lucid dream frequency, and emotional intensity show a reduction in T3 than T1. Moreover, the Improved group is characterized by lower nightmare rate and nightmare distress than Not Improved people. Our findings confirmed that beyond the trait-like variables (ie, age, sex), specific sleep-related measures are related to nightmare features. In particular, poor sleep hygiene was one of the best determinants of nightmare distress among Not Improved subjects.

Conclusion

Our findings revealed that people experienced an adaptation to the pandemic during the third wave. We also strengthen the notion that nightmares and their variations over time are strongly related to human well-being, suggesting that specific trait-like and sleep-related factors could modulate the relationship between mental health and nightmare features.

Sleep disturbance and anxiety symptoms among asymptomatic COVID-19 carriers in Shanghai, China: the mediating role of entrapment and defeat

BACKGROUND

The COVID-19 pandemic increases the risk of psychological problems, especially for the infected population. Sleep disturbance and feelings of defeat and entrapment are well-documented risk factors of anxiety symptoms. Exploring the psychological mechanism of the development of anxiety symptoms is essential for effective prevention. This study aimed to examine the mediating effects of entrapment and defeat in the association between sleep disturbance and anxiety symptoms among asymptomatic COVID-19 carriers in Shanghai, China.

METHODS

A cross-sectional study was conducted from March to April, 2022. Participants were 1,283 asymptomatic COVID-19 carriers enrolled from the Ruijin Jiahe Fangcang Shelter Hospital, Shanghai (59.6% male; mean age = 39.6 years). Questionnaire measures of sleep disturbance, entrapment, defeat, anxiety symptoms, and background characteristics were obtained. A mediation model was constructed to test the mediating effects of entrapment and defeat in the association between sleep disturbance and anxiety symptoms.

RESULTS

The prevalence rates of sleep disturbance and anxiety symptoms were 34.3% and 18.8%. Sleep disturbance was positively associated with anxiety symptoms (OR [95%CI] = 5.013 [3.721-6.753]). The relationship between sleep disturbance and anxiety symptoms (total effect: Std. Estimate = 0.509) was partially mediated by entrapment (indirect effect: Std. Estimate = 0.129) and defeat (indirect effect: Std. Estimate = 0.126). The mediating effect of entrapment and defeat accounted for 50.3% of the association between sleep disturbance and anxiety symptoms.

CONCLUSION

Sleep disturbance and anxiety symptoms were prevalent among asymptomatic COVID-19 carriers. Entrapment and defeat mediate the association between sleep disturbance and anxiety symptoms. More attention is needed to monitoring sleep conditions and feelings of defeat and entrapment to reduce the risk of anxiety.

Delayed sleep-wake rhythm due to staying at home during the COVID-19 pandemic and sleep debt after returning to campus among Japanese nursing university students: A longitudinal study

This study aimed to investigate sleep problems during staying at home due to the coronavirus disease 2019 (COVID-19) pandemic and after returning to campus among university nursing students. We analyzed data from self-reported sleep surveys conducted during a nursing course at a university in Tokyo between 2019 and 2021. During staying at home due to COVID-19, we observed delayed sleep-wake rhythm, prolonged sleep duration on weekdays, a decreased sleep debt, improved daytime sleepiness, and worsened insomnia, especially in terms of difficulty initiating sleep (Study 1; 18 paired data). After returning to campus, we found advanced wake-up time, shortened sleep duration, increased sleep debt, worsened insomnia, and increased daytime sleepiness (Study 2; 91 paired data). The association between advanced midpoint of sleep and commute time over an hour (aOR, 3.29; 95%CI: 1.24-8.72) was confirmed. Furthermore, sleep paralysis and nightmares were more prevalent among nursing students with an advanced midpoint of sleep, whereas nursing students whose midpoint of sleep was delayed had higher daytime sleepiness after returning to campus. To maintain regular sleep-wake rhythms and sufficient sleep duration, the educational environment surrounding nursing university students (e.g., curriculum, class schedule, style of class) should be established considering their age-dependent biological rhythm in addition to sleep hygiene education for students.

Adolescent Victimization during COVID-19 Lockdowns and Its Influence on Mental Health Problems in Seven Countries: The Mediation Effect of Resilience

The objective of this study was to test the differences between the mean scores of victimization, an indicator of depression, stress, and anxiety (DASS), across seven countries (Australia, Chile, India, Indonesia, Mexico, Poland, and the Russian Federation) during the COVID-19 lockdowns. In addition, this study sought to analyze the mediator role of resilience in these relationships in the different countries. To this end, a structural equation model (SEM) was tested and differences across countries were considered through a multigroup analysis. Data for adolescent students from seven countries (n = 7241) collected by the Global Research Alliance showed that levels of anxiety, depression, and stress among adolescents were different in the countries assessed; all of them presented values above the mean of the indicator, with Chile and Russia having the highest values. Regarding the prevalence of exposure to violence, the mean across all countries studied was 34%, with the highest prevalence in Russia and India. At the global level, an adequate adjustment was observed in the SEM mediation model considering all countries. However, a mediator effect of resilience was only observed in the relationship between victimization and the indicator of DASS in Chile, Indonesia, and Russia. The results are discussed, analyzing the relevance of resilience as a protective factor for mental health during COVID-19 lockdowns.

Effects of dysfunctional beliefs about sleep on sleep quality and mental health among patients with COVID-19 treated in Fangcang shelter hospitals

Introduction

With the COVID-19 pandemic in China, a large number of mild or ordinary confirmed cases have been sent to Fangcang shelter hospitals for treatment. We aimed to investigate the mental health condition of Fangcang patients 2 years after the pandemic when patients knew more about COVID-19 and the virus was less virulent. We focused on the effect of dysfunctional beliefs and attitudes about sleep on depression, anxiety, and insomnia.

Methods

A total of 1,014 patients from two large Fangcang shelter hospitals in Shanghai between 22 April and 8 May 2022 completed a set of questionnaires comprising: the Dysfunctional Beliefs and Attitudes about Sleep scale, the Generalized Anxiety Disorder scale, the Patient Health Questionnaire, and the Insomnia Severity Index scale.

Results

Results show that the positive screening rates for anxiety, depression, and insomnia among tested patients were 55.3, 27.0, and 47.8%, respectively. Patients were more likely to report higher anxiety, depression, and insomnia, and to endorse affective and sleep disorders if they were: female, aged 18-40 years, with undergraduate course or above, white-collar employees, or those who thought the pandemic would have severe economic effects. About 51.4% of the participants had dysfunctional beliefs about sleep to varying degrees. Compared with patients who had accurate beliefs about sleep, the ratios of insomnia, anxiety, and depression were significantly higher among patients with dysfunctional beliefs about sleep.

Discussion

Attention should be paid to the mental health problems of patients in Fangcang shelter hospitals. The results indicate that dysfunctional beliefs about sleep significantly increased anxiety, depression, and insomnia of Fangcang patients.

Converging theories on dreaming: Between Freud, predictive processing, and psychedelic research

Dreams are still an enigma of human cognition, studied extensively in psychoanalysis and neuroscience. According to the Freudian dream theory and Solms' modifications of the unconscious derived from it, the fundamental task of meeting our emotional needs is guided by the principle of homeostasis. Our innate value system generates conscious feelings of pleasure and unpleasure, resulting in the behavior of approaching or withdrawing from the world of objects. Based on these experiences, a hierarchical generative model of predictions (priors) about the world is constantly created and modified, with the aim to optimize the meeting of our needs by reducing prediction error, as described in the predictive processing model of cognition. Growing evidence from neuroimaging supports this theory. The same hierarchical functioning of the brain is in place during sleep and dreaming, with some important modifications like a lack of sensual and motor perception and action. Another characteristic of dreaming is the predominance of primary process thinking, an associative, non-rational cognitive style, which can be found in similar altered states of consciousness like the effect of psychedelics. Mental events that do not successfully fulfill an emotional need will cause a prediction error, leading to conscious attention and adaptation of the priors that incorrectly predicted the event. However, this is not the case for repressed priors (RPs), which are defined by the inability to become reconsolidated or removed, despite ongoing error signal production. We hypothesize that Solms' RPs correspond with the conflictual complexes, as described by Moser in his dream formation theory. Thus, in dreams and dream-like states, these unconscious RPs might become accessible in symbolic and non-declarative forms that the subject is able to feel and make sense of. Finally, we present the similarities between dreaming and the psychedelic state. Insights from psychedelic research could be used to inform dream research and related therapeutic interventions, and vice versa. We propose further empirical research questions and methods and finally present our ongoing trial "Biological Functions of Dreaming" to test the hypothesis that dreaming predicts intact sleep architecture and memory consolidation, via a lesion model with stroke patients who lost the ability to dream.

Presleep focusing on positive spontaneous thoughts enhanced the possibility of dreaming of them

Introduction

Dreaming is the subjective experience during sleep. A spontaneous thought is a thought that comes to one's mind involuntarily. This study investigated whether presleep focusing on a positive spontaneous thought enhanced the possibility of dreaming of the thought.

Methods

Ninety-seven participants were quasi-randomly assigned to an expression condition (focus on an spontaneous thought for 5-Min before sleeping; N = 45) and a control condition (think about anything for 5-Min before sleeping; N = 45). Participants completed a dream diary upon waking. Then, both participants themselves (the selfrating method) and external judges (the external-rating method) rated the correlation between the positive spontaneous thought and the dream.

Results

The result of the external-rating method indicated that presleep focusing on positive spontaneous thoughts enhanced the possibility of dreaming of the thoughts. In addition, the external-rating method found that presleep focusing on positive spontaneous thoughts enhanced the possibility of dreaming of thoughts that were related to the positive spontaneous thoughts but not the positive spontaneous thoughts themselves.

Discussion

These results supported the current concern theory which suggests that one's current concerns increase responses to cues related to the concerns implicitly. In addition, these results supported the continuity hypothesis which states that dreaming is in continuous with waking life, and thus the intensity of a daily concern may be related to the possibility of dreaming of the daily concern.

The role of sleep and dreams in long‐ COVID

Recent investigations show that many people affected by SARS-CoV2 (COVID-19) report persistent symptoms 2-3 months from the onset of the infection. Here, we report the Italian findings from the second International COVID-19 Sleep Study survey, aiming to investigate sleep and dream alterations in participants with post-acute symptoms, and identify the best determinants of these alterations among patients with long-COVID. Data from 383 participants who have had COVID-19 were collected through a web-survey (May-November 2021). Descriptive analyses were performed to outline the sociodemographic characteristics of long-COVID (N = 270, with at least two long-lasting symptoms) and short-COVID (N = 113, with none or one long-lasting symptom) participants. They were then compared concerning sleep and dream measures. We performed multiple linear regressions considering as dependent variables sleep and dream parameters discriminating the long-COVID group. Age, gender, work status, financial burden, COVID-19 severity and the level of care were significantly different between long-COVID and short-COVID subjects. The long-COVID group showed greater sleep alterations (sleep quality, daytime sleepiness, sleep inertia, naps, insomnia, sleep apnea, nightmares) compared with the short-COVID group. We also found that the number of long-COVID symptoms, psychological factors and age were the best explanatory variables of sleep and oneiric alterations. Our findings highlight that sleep alterations are part of the clinical presentation of the long-COVID syndrome. Moreover, psychological status and the number of post-acute symptoms should be considered as state-like variables modulating the sleep problems in long-COVID individuals. Finally, according to previous investigations, oneiric alterations are confirmed as a reliable mental health index.

An observatory on changes in dreaming during a pandemic: a living systematic review (part 1)

A 'new' way of dreaming has emerged during the pandemic, enhancing the interest of psychological literature. Indeed, during the years of the spread of coronavirus disease 2019 (COVID-19), many studies have investigated dream-related phenomena and dreaming functions. Considering the constant and rapid emergence of new results on this topic, the main aim of this study was to create an 'observatory' on the short- and long-term consequences of the COVID-19 pandemic on dreaming, by means of a living systematic review. The baseline results are presented, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines, to identify and discuss existing studies about dreams and dreaming during the COVID-19 pandemic published until February 2022. Web of Science, Embase, EBSCO, and PubMed were used for the search strategy, yielding 71 eligible papers included in the review. Our results show: (a) a more intense oneiric activity during lockdown; (b) changes in dreaming components (especially dream-recall and nightmare frequency); (c) a particular dreaming scenario ('pandemic dreams'); (d) an alteration of the dreaming-waking-life continuum and a specific function of dreaming as emotional regulator. Findings suggest that monitoring changes in dreaming provides important information about psychological health and could also contribute to the debate on the difficulties of dreaming, as well as sleeping, in particular during and after a period of 'collective trauma'.

M, T. F, M. M, A. S, G. H, M. J, L. G, L. B, T. Z. L, B. H, S. R, S. MR. 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.

Dreaming during the COVID-19 pandemic: A narrative review

According to several influential models, dreams can be affected by state- and trait-like factors, sleep features, and diurnal experiences. The COVID-19 pandemic globally affected daily habits, emotional experiences, and sleep. Previous studies suggested an influence of collective traumatic events on dreaming. Starting from these premises, several studies assessed the effect of the pandemic on dreams. This paper aims to review findings concerning the oneiric activity during the COVID-19 pandemic. We report pandemic-related changes in dreams and nightmares, and we consider the possible factors associated with dreaming. Moreover, we provide results about changes in the oneiric activity in different phases of the pandemic. The reviewed findings suggest a pandemic-related enhancement of dream and nightmare frequency, emotional intensity, and distressing contents, modulated by modifications in restrictive measures and associated with diurnal experiences, emotional status, and sleep pattern. We highlight several methodological issues and a large heterogeneity in the present literature, limiting results’ generalizability. However, we provide possible interpretations of the most consistent findings in light of the main theoretical frameworks about dreaming.

Dreams and nightmares during the pandemic

The pandemic caused by the coronavirus disease 2019 (COVID-19) had a huge impact on public mental health. This was also reflected in dreams. Not only did people start to remember more dreams, but dream content changed as themes like sickness, confinement, and—in the English-speaking world—even bugs began to dominate. This also led to an increase in nightmare frequency. There are various factors that contributed to this change in the dream landscape. Some people have started to sleep more and hereby spend more time in REM sleep, which is known to increase dream recall and further lead to bizarre and vivid dreams. On the other hand, stress and poor mental health had an impact on sleep, and sleep quality thus dropped in many individuals. Poor sleep quality can also lead to an increase in dream recall. Dreams are known to regulate mood, so the rise in dreams and the change in dream content could also reflect a reaction to the overall rise in stress and decline in mental health. Recent studies have shown that as the pandemic progresses, further changes in mental health, dream recall, and dream content arise, but data are still scarce. Further research could help understand the impact the pandemic still has on mental health and dreams, and how this impact is changing over the course of the pandemic.

What about dreams? State of the art and open questions

Several studies have tried to identify the neurobiological bases of dream experiences, nevertheless some questions are still at the centre of the debate. Here, we summarise the main open issues concerning the neuroscientific study of dreaming. After overcoming the rapid eye movement (REM) ‐ non‐REM (NREM) sleep dichotomy, investigations have focussed on the specific functional or structural brain features predicting dream experience. On the one hand, some results underlined that specific trait‐like factors are associated with higher dream recall frequency. On the other hand, the electrophysiological milieu preceding dream report upon awakening is a crucial state‐like factor influencing the subsequent recall. Furthermore, dreaming is strictly related to waking experiences. Based on the continuity hypothesis, some findings reveal that dreaming could be modulated through visual, olfactory, or somatosensory stimulations. Also, it should be considered that the indirect access to dreaming remains an intrinsic limitation. Recent findings have revealed a greater concordance between parasomnia‐like events and dream contents. This means that parasomnia episodes might be an expression of the ongoing mental sleep activity and could represent a viable direct access to dream experience. Finally, we provide a picture on nightmares and emphasise the possible role of oneiric activity in psychotherapy. Overall, further efforts in dream science are needed (a) to develop a uniform protocol to study dream experience, (b) to introduce and integrate advanced techniques to better understand whether dreaming can be manipulated, (c) to clarify the relationship between parasomnia events and dreaming, and (d) to determine the clinical valence of dreams.

The Oneiric Activity during and after the COVID-19 Total Lockdown in Italy: A Longitudinal Study

A growing body of evidence highlights that the COVID-19 pandemic affected oneiric activity. However, only a few studies have assessed the longitudinal changes in dream phenomenology during different phases of the pandemic, often focused on a limited number of dream variables. The aim of the present study was to provide an exhaustive assessment of dream features during total lockdown (TL) and a post-lockdown (PL) period characterized by eased restrictive measures in Italy. We performed a longitudinal study using a web-based survey to collect demographic, COVID-19 related, clinical, sleep, and dream data at TL and PL. Our final sample included 108 participants. The high frequency of poor sleep quality, anxiety, and depressive symptoms observed during TL remained stable at PL, while sleep latency (t = −4.09; p < 0.001) and PTSD-related disruptive nocturnal behaviors (t = −5.68; p < 0.001) exhibited a reduction at PL. A PL decrease in time spent with digital media was observed (t = −2.77; p = 0.007). We found a strong PL reduction in dream frequency (t = −5.49; p < 0.001), emotional load (t = −2.71; p = 0.008), vividness (t = −4.90; p < 0.001), bizarreness (t = −4.05; p < 0.001), length (t = −4.67; p < 0.001), and lucid dream frequency (t = −2.40; p = 0.018). Fear was the most frequently reported emotion in dreams at TL (26.9%) and PL (22.2%). Only the frequency of specific lockdown-related dream contents exhibited a reduction at PL. These findings highlight that the end of the home confinement had a strong impact on the oneiric activity, in the direction of reduced dream frequency, intensity, and lockdown-related contents. The co-occurrence of such changes with a decline in nocturnal PTSD-related symptoms, sleep latency, and time with digital media suggests an influence of post-traumatic stress levels, lifestyle modifications, and sleep pattern on dream changes during different phases of the pandemic. The stable prevalence of fear in dreams and the large frequency of poor sleep quality, depressive symptoms, and anxiety are probably related to the persistence of many negative consequences of the pandemic. Overall, these results are consistent with the continuity hypothesis of dreams.

Cognitive Impairment in Convalescent COVID-19 Patients Undergoing Multidisciplinary Rehabilitation: The Association with the Clinical and Functional Status

Background. Cognitive impairment has been reported in the aftermath of severe acute respiratory syndrome due to coronavirus 2 (SARS-CoV-2) infection. We investigated the possible association between cognitive impairment and the main clinical and functional status variables in a cohort of convalescent COVID-19 patients without premorbid diseases potentially affecting cognition. Methods. We consecutively screened for inclusion of convalescent COVID-19 patients referring to a post-acute care facility for pulmonary rehabilitation. All the enrolled patients were assessed for cognitive functions. We also investigated features of psychological distress (anxiety, depression, symptoms of posttraumatic stress disorder and quality of life) and cardiac and pulmonary functional status. Results. The 63 enrolled patients (mean age 59.82 ± 10.78, male gender = 47) showed a high frequency of depressive symptoms (76.2%) and anxiety (55.5%), and a high prevalence of symptoms of posttraumatic stress disorder (PTSD, 44.4%). About half of the total sample showed reduced cognitive efficiency (RCE, 44.4%) in the domains of spatial and verbal long-term memory and executive functions. Patients with RCE more frequently showed alteration of blood pressure (BP) circadian rhythm (p = 0.01), higher levels of D-Dimer (p = 0.03), had experienced a severe illness (p = 0.02), had longer disease duration (p = 0.04), more clinically relevant symptoms of PTSD (p = 0.02), more frequent cognitive complaints (p = 0.002), higher anxiety scores (p = 0.01) and lower quality of life (p = 0.02) than patients with normal cognitive efficiency. Conclusions. Our findings indicated a possible association between the RCE after COVID-19 and some cardiological variables, including some indirect measures of a residual autonomic disorder, such as the presence of an altered BP circadian rhythm. Future research studies with large samples are needed to provide valid conclusions.

Has the COVID-19 Pandemic Traumatized Us Collectively? The Impact of the COVID-19 Pandemic on Mental Health and Sleep Factors via Traumatization: A Multinational Survey

PURPOSE

The COVID-19 pandemic affects mental health and sleep, resulting in frequent nightmares. Therefore, identifying factors associated with nightmare frequency is important, as it can indicate mental health issues. The study aimed to investigate increases in nightmare frequency comparing the pre-pandemic and pandemic period, and identify its risk factors. Further, the mediating role of post-traumatic stress disorder symptoms between the pandemic and nightmares is explored.

PATIENTS AND METHODS

For this cross-sectional survey data were obtained via self-rating online survey (ICOSS: details in Partinen et al, 2021), which was open to anyone older than 18 years. The final volunteer sample consisted of 15,292 participants, divided according to their nightmare frequency (high: ≥1-2 nights/week; low: <1-2 nights/week). A total of 9100 participants were excluded if answers on variables of interest were missing or receiving rewards for participation. Chi-square tests identified changes of nightmare frequency. Predictors of high nightmare frequency were assessed using logistic regression and presented as Odds Ratios. Post-hoc mediation models were used to investigate the role of post-traumatic stress symptoms (PTSS).

RESULTS

The mean age was 41.63 (SD=16.55) with 64.05% females. High nightmare frequency increased significantly from 13.24% to 22.35% during the pandemic. Factors associated with it included self-reported PTSS (OR=2.11), other mental disorders and various sleep disorders or problems. Financial burden due to the pandemic, confinement, having had COVID-19, and work situation during the pandemic were associated with nightmare frequency, those relations were partly mediated through PTSS.

CONCLUSION

Our results display the pandemic influence on nightmare frequency, which in turn connects to multiple mental health and sleep factors. These relations were partly mediated through PTSS. The COVID-19 pandemic appears to have caused traumatization of a substantial proportion of society. Health care workers should consider nightmares in their screening routines, as it might indicate PTSS and/or other mental and sleep disorders.