Luigi De Gennaro

• Full Professor
• Professor (Full) at Sapienza University of Rome

To study the impact of the COVID‐19 pandemic on sleep and circadian rhythms—two fundamental pillars for health—the collaboration International COVID‐19 Sleep Study (ICOSS) was established. The present overview comprehensively discusses the findings from this collaboration. Involving sleep researchers across the globe, ICOSS used a harmonised questi...

Insomnia disorder (ID) is characterized by electroencephalographic indexes of hyperarousal, often associated with the underestimation of sleep duration (i.e., sleep state misperception). Albeit NREM sleep K-complexes (KCs) are involved in sleep protection and arousal, only a few studies investigated their alterations in ID with heterogenous finding...

The aim of the present study is to investigate differences in brain networks modulation during the pre- and post-sleep onset period, both within and between two groups of young and older individuals. Thirty-six healthy elderly and 40 young subjects participated. EEG signals were recorded during pre- and post-sleep onset periods and functional conne...

The gestational period is a sensitive time marked by significant changes that can affect women's sleep and dreaming processes, with an augmented frequency and recall of dreams suggesting that dreaming represents an adaptive mechanism of emotional regulation. This study investigates the relationship between pregnancy‐related variables, alexithymia,...

Dreams have always fascinated humans [...]

Study Objectives:Obstructive sleep apnea (OSA) is considered a risk factor for sleepiness at the wheel (SW) and near-miss accidents (NMA). To date, there are subjective and objective methods such as the Maintenance of Wakefulness Test (MWT) to investigate sleepiness. However, these methods have limitations. Therefore, a new analysis of the MWT was...

Introduction: Attentional Bias (AB) is the tendency among individuals with emotional dysregulation to preferentially allocate attention toward negative emotional stimuli rather than positive ones, influencing the encoding and consolidation of emotional events. Targeted Memory Reactivation (TMR) holds promise in memory enhancement by reactivating sp...

Purpose of review Dreaming has only recently become a topic of scientific research. This review updates current findings on dream studies, emphasizing recent research on the neural mechanisms of dreaming. Additionally, it summarizes new evidence on the functional role of dreams, including insights from studies on dreams and nightmares during the co...

The current study aimed (1) to provide an analysis of the frequency and prevalence of sleep disturbances in a large Italian sample of children and adolescents with ASD, detecting specific predictors of the presence/absence of sleep disorders, (2) to examine the phenomenon of co-sleeping within a subgroup of participants with ASD. A total of 242 chi...

Background Preliminary data suggests that obesity might hasten the decline in mRNA vaccine-induced immunity against SARS-CoV-2. However, whether this renders individuals with obesity more susceptible to long COVID symptoms post-vaccination remains uncertain. Given sleep’s critical role in immunity, exploring the associations between obesity, probab...

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 paras...

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...

Accurate measurement of habitual sleep duration (HSD) is crucial for understanding the relationship between sleep and health. This study aimed to assess the bias and agreement limits between two commonly used short HSD self-report methods, considering sleep quality (SQ) and social jetlag (SJL) as potential predictors of bias. Data from 10,268 parti...

Human sleep physiology is strongly affected by age [...]

Sleep state misperception (SSM) is a common issue in insomnia disorder (ID), causing a discrepancy between objective and subjective sleep/wake time estimation and increased daytime impairments. In this context, the hyperarousal theory assumes that sustained central nervous system activation contributes to the SSM. This study investigates factors in...

Background Delaying school start times has been proposed as a potential solution to address chronic sleep curtailment among adolescents and its negative consequences on their physical and mental well-being. This study investigates the impact of delayed school start times due to the COVID-19 pandemic on academic achievement. Subjects and Methods Tw...

Diagnostic manuals describe insomnia disorder (ID) characterised by fatigue and sleepiness as diurnal consequences of nocturnal symptoms. However, patients with ID do not frequently report sleepiness in the clinical setting. The present study aimed to investigate subjective sleepiness in ID measured through the Epworth Sleepiness Scale (ESS) and it...

Insomnia is the most reported sleep disorder in industrialized countries, affecting, in the chronic form, around 10% of the European population. In Italy, such a percentage seems to be even higher. Although insomnia can be an independent disorder, it is frequently described as comorbid condition and may precipitate, exacerbate, or prolong a broad r...

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 s...

Multiple Sclerosis (MS) is a neurodegenerative disease that mainly affects young adults. The high prevalence of the disease and its impact on patients' quality of life led to priority being given to the etiopathogenesis of the disease to identify possible modifiable factors and consequent effective intervention strategies. Recent hypotheses suggest...

Study objectives: Preliminary evidence suggests that the risk of Long COVID is higher among people with pre-existing medical conditions. Based on its proven adjuvant role in immunity, habitual sleep duration may alter the risk for developing Long COVID. The objective of this study was to determine whether the odds of Long COVID are higher amongst...

The Coronavirus 2019 (COVID‐19) pandemic significantly influenced physical and mental health worldwide. The present study aimed to investigate changes in sleep problems across three waves of the COVID‐19 pandemic, and to identify potential predictors of the inter‐individual variability around these changes, with a particular focus on the role of de...

The present literature points to an alteration of the human K‐complex during non‐rapid eye movement sleep in Alzheimer's disease. Nevertheless, the few findings on the K‐complex changes in mild cognitive impairment and their possible predictive role on the Alzheimer's disease conversion show mixed findings, lack of replication, and a main interest...

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...

Electroencephalography (EEG) studies of dreaming are an integral paradigm in the study of neurocognitive processes of human sleep and consciousness, but they are limited by the number of observations that can be collected per study. Dream studies also involve substantial methodological and conceptual variability which poses problems for the integra...

The imposition of lockdowns during the COVID-19 pandemic placed individuals under conditions of environmental stress, threatening individual and collective wellbeing. This study aimed to investigate the temporal effects of isolation and confinement during and after the Italian lockdown on decision-making, risk propensity, and cognitive control proc...

Background: The COVID-19 pandemic and related restriction measures have affected our daily life, sleep, and circadian rhythms worldwide. Their effects on hypersomnolence and fatigue remain unclear. Methods: The International COVID-19 Sleep Study questionnaire which included items on hypersomnolence such as excessive daytime sleepiness (EDS), and...

Sleep changes significantly throughout the human lifespan. Physiological modifications in sleep regulation, in common with many mammals (especially in the circadian rhythms), predispose adolescents to sleep loss until early adulthood. Adolescents are one-sixth of all human beings and are at high risk for mental diseases (particularly mood disorders...

In recent years, transcranial electrical stimulation techniques have demonstrated their ability to modulate our levels of sleepiness and vigilance. However, the outcomes differ among the specific aspects considered (physiological, behavioural or subjective). This study aimed to observe the effects of bifrontal anodal transcranial direct current sti...

Short nighttime sleep duration impairs the immune response to virus vaccination, and long nighttime sleep duration is associated with poor health status. Thus, we hypothesized that short (<6 h) and long (>9 h) nighttime sleepers have a higher post-COVID risk than normal nighttime sleepers, despite two doses of mRNA vaccine (which has previously bee...

COVID-19 has challenged the health workforce worldwide. In this cross-sectional study with a retrospective assessment, we explored the impact of the pandemic on mental health and sleep among a sample of Italian nurses and medical doctors. A total of 287 healthcare workers (212 nurses and 75 physicians) completed a web survey on socio-demographic, p...

The present study had two main aims. First, to investigate whether shift/night workers had a higher prevalence and severity of COVID-19 compared with day workers. Second, to investigate whether people regularly working in face-to-face settings during the pandemic exhibited a higher prevalence and severity of COVID-19 compared with those having no n...

Background Transcutaneous auricular vagus nerve stimulation (taVNS) stimulating the auricular branch of the vagus nerve along a well-defined neuroanatomical pathway, has promising therapeutic efficacy. Potentially, taVNS can modulate autonomic responses. Specifically, taVNS can induce more consistent parasympathetic activation and may lead to incre...

After the appearance of a novel coronavirus (2019-nCoV) during 2019, the virus has spread with alarming speed and a pandemic quickly developed [...]

Background: Sleep talking (ST) is characterized by the production of unaware verbal vocal activations (VBs) during sleep. ST seems potentially linked to linguistic and memory consolidation processes. However, sleep and dream characteristics and the relationship between verbal vocalizations (VBs) and cognitive functions are still unknown. Our study...

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 t...

Rapid eye movement (REM) sleep behaviour disorder is a REM sleep parasomnia characterised by the loss of the physiological muscle atonia during REM sleep, resulting in dream enactment behaviours that may cause injuries to patients or their bed partners. The nocturnal motor episodes seem to respond to the dream contents, which are often vivid and vi...

Sleep parasomnias have drawn the interest of sleep experts because they represent a valuable window to directly monitor dream activity and sleep mentation associated with nocturnal events. Indeed, parasomnias and their manifestations are helpful in investigating dream activity and features, overcoming methodological limits that affect dream study....

Evidence on the relation between binge-watching and sleep quality is still scarce and inconsistent and none has taken into account both the healthy and pathological dimensions of the phenomenon. This study aimed at filling this gap by investigating both aspects in healthy participants with high and low sleep quality. Further, we aimed at identifyin...

Many people report suffering from post‐acute sequelae of COVID‐19 or “long‐COVID”, but there are still open questions on what actually constitutes long‐COVID and how prevalent it is. The current definition of post‐acute sequelae of COVID‐19 is based on voting using the Delphi‐method by the WHO post‐COVID‐19 working group. It emphasizes long‐lasting...

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 ri...

Abstract Purpose: Obstructive sleep apnea (OSA) may increase the risk of severe COVID-19; however, the level of potential modulation has not yet been established. The objective of the study was to determine the association between high risk of OSA, comorbidities, and increased risk for COVID-19, hospitalization, and intensive care unit (ICU) treatm...

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 s...

There has been increasing concern about the long‐term impact of coronavirus disease 2019 (COVID‐19) as evidenced by anecdotal case reports of acute‐onset parkinsonism and the polysomnographic feature of increased rapid eye movement sleep electromyographic activity. This study aimed to determine the prevalence and correlates of dream‐enactment behav...

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 focuss...

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 d...

Aim of the present study is to investigate the alterations of brain networks derived from EEG analysis in pre- and post-sleep onset conditions after 40 h of sleep deprivation (SD) compared to sleep onset after normal sleep in 39 healthy subjects. Functional connectivity analysis was made on electroencelographic (EEG) cortical sources of current den...

Endowed with inherent flexibility, wearable robotic technologies are powerful devices that are known to extend bodily functionality to assist people with spinal cord injuries (SCIs). However, rather than considering the specific psychological and other physiological needs of their users, these devices are specifically designed to compensate for mot...

Introduction A growing number of studies have demonstrated that the coronavirus disease-19 (COVID-19) pandemic has severely affected sleep and dream activity in healthy people. To date, no investigation has examined dream activity specifically in COVID-19 patients. Methods As part of the International COVID-19 Sleep Study (ICOSS), we compared 544...

Spinal cord injuries (SCI) are disruptive neurological events that severly affect the body leading to the interruption of sensorimotor and autonomic pathways. Recent research highlighted SCI-related alterations extend beyond than the expected network, involving most of the central nervous system and goes far beyond primary sensorimotor cortices. Th...

This protocol paper describes the second survey produced by the International Covid Sleep Study (ICOSS) group with the aim to examine the associations between SARS-CoV-2 infection and sleep, sleepiness, and circadian problems as potential predisposing factors for more severe COVID-19 disease profile and for development of Long-COVID in the general...

Study Objectives Sleep talking (ST) has been rarely studied as an isolated phenomenon. Late investigations over the psycholinguistic features of vocal production in ST pointed to coherence with wake language formal features. Therefore, we investigated the EEG correlates of Verbal ST as the overt manifestation of sleep-related language processing, w...

Objectives Sleep is important for human health and well-being. No previous study has assessed whether the COVID-19 pandemic impacts sleep and daytime function across the globe. Methods This large-scale international survey used a harmonised questionnaire. Fourteen countries participated during the period of May–August 2020. Sleep and daytime probl...

The effects of the COVID-19 pandemic on sleep have been widely documented, but longitudinal evaluations during different phases of the “COVID-19 era” are needed to disentangle the specific consequences of the r145estrictive measures on sleep variables. The aim of this study was to assess the immediate effect of the lockdown’s end on sleep and sleep...

Insomnia (ID) is the most common sleep disorder; however pathogenetic mechanisms underlying ID symptoms are not fully understood. Adopting a multifactorial view and considering ID a condition that involves interregional neuronal coordination would be useful to understand the ID pathophysiology. Functional connectivity (FC) may help to shed light on...

Recent literature shows that the Coronovirus-19 (COVID-19) pandemic has provoked significant changes in dreaming. The current study intends to provide an update about dream variable changes during the second wave of COVID-19. A total of 611 participants completed a web survey from December 2020 to January 2021. Statistical comparisons showed that s...

Importance: The association of fast backward-rotating shift work (ie, anticlockwise sequence of afternoon, morning, and night shifts) with subjective and objective measures of sleep-wake quality, daytime attention, and tiredness of health care workers has not yet been established. Objective: To investigate the association of shift rotation directi...

Purpose Lifestyle and work habits have been drastically altered by restrictions due to the COVID-19 pandemic. Whether the associated changes in sleep timing modulate the risk of suffering from symptoms of insomnia, the most prevalent sleep disorder, is however incompletely understood. Here, we evaluate the association between the early pandemic-ass...

A large body of evidence has documented the impact of the global COVID‐19 outbreak – and especially the lockdown period – on sleep quality and quantity. Here, we present the first Italian longitudinal study on sleep and COVID‐19 considering four different time points collected during lockdown (from 29 March 2020 to 3 May 2020) and a subsequent foll...

Underlying neural mechanisms and cognitive implications of non-Rapid Eye Movement (NREM) sleep in isolated REM sleep behavior disorder (iRBD) are not yet fully elucidated. This study aims to evaluate brain metabolic connectivity of the anterior default mode network (ADMN) underlying a waveform that is an hallmark of NREM sleep, namely K-complex (KC...

Objective The COVID-19 pandemic has strongly affected daily habits and psychological wellbeing, and many studies point to large modifications in several sleep and sleep-related domains. Nevertheless, pre-sleep arousal during the pandemic has been substantially overlooked. Since hyperarousal represents one of the main factors for the development and...

Healthy aging is characterized by macrostructural sleep changes and alterations of regional electroencephalographic (EEG) sleep features. However, the spatiotemporal EEG pattern of the wake-sleep transition has never been described in the elderly. The present study aimed to assess the topographical and temporal features of the EEG during the sleep...

Objective Many have reported odd dreams during the pandemic. Given that dreams are associated with mental health, understanding these changes could provide crucial information about wellbeing during the pandemic. This study explored associations between COVID-19 and dream recall frequency (DRF), and related social, health, and mental health factors...

Recent evidence showed that EEG activity alterations that occur during sleep are associated with structural, age-related, changes in healthy aging brains, and predict age-related decline in memory performance. Alzheimer’s disease (AD) patients show specific EEG alterations during sleep associated with cognitive decline, including reduced sleep spin...

Study Objectives Individual circadian type is a ubiquitous trait defining sleep, with eveningness often associated with poorer sleep and mental health than morningness. However, it is unknown whether COVID-19 pandemic has differentially affected sleep and mental health depending on the circadian type. Here, the differences in sleep and mental healt...

Background: Several studies highlighted that sleepiness affects driving abilities. In particular, road traffic injuries due to excessive daytime sleepiness are about 10–20%. Considering that aging is related to substantial sleep changes and the number of older adults with driving license is increasing, the current review aims to summarize recent st...

Insomnia and obstructive sleep apnea (OSA) are two prevalent sleep disorders which share nocturnal sleep disturbances, impairments to daytime activity and quality of life, and high healthcare and social costs [...]

Importance and Study Objective The COVID-19 pandemic has produced unprecedented changes in social, work, and leisure activities, which all have had major impact on sleep and psychological well-being. This study documented the prevalence of clinical cases of insomnia, anxiety, and depression and selected risk factors (COVID-19, confinement, financia...

The restrictions imposed by the Italian government because of the coronavirus outbreak have been shown to be demanding on the Italian population. Data were collected at four different time points from 29 March 2020 to 3 May 2020 and during the final follow-up survey on 12 October 2020. In the present study, we provided longitudinal evidence on the...

The Coronavirus 2019 pandemic strongly affected our sleep and dream activity. Many cross‐sectional studies highlighted increased dream recall frequency, and revealed a great presence of pandemic‐related oneiric contents. Here, we present the first prospective study carried out on an Italian sample. One‐hundred subjects were requested to fill out a...

Introduction Non-rapid eye movement (NREM) parasomnias are defined as abnormal nocturnal behaviors that typically arise from the NREM sleep stage 3 during the first sleep cycle. The polysomnographic studies showed an increase in sleep fragmentation and an atypical slow wave activity (SWA) in participants with NREM parasomnias compared to healthy co...

Purpose Obstructive sleep apnea (OSA) may increase the risk of severe COVID-19; however, the level of potential modulation has not yet been established. The objective of the study was to determine the association between high risk of OSA, comorbidities, and increased risk for COVID-19, hospitalization, and intensive care unit (ICU) treatment. Meth...

Some studies highlighted that patients with narcolepsy type-1 (NT1) experience high lucid dream frequency, and this phenomenon has been associated with a creative personality. Starting from the well-known “pandemic effect” on sleep and dreaming, we presented a picture of dream activity in pharmacologically treated NT1 patients during the Italian lo...

A growing body of evidence consistently describes the side‐effects of coronavirus disease 2019 lockdown on mental health and sleep quality. We conducted a longitudinal web‐based survey of 217 Italian participants at two time points: lockdown and subsequent follow‐up. To thoroughly investigate lockdown‐related changes in sleep quality, we first eval...

The multifactorial nature of Alzheimer’s disease (AD) has led scientific researchers to focus on the modifiable and treatable risk factors of AD. Sleep fits into this context, given the bidirectional relationship with AD confirmed by several studies over the last years. Sleep disorders appear at an early stage of AD and continue throughout the enti...

AD patients undergo a slowing of waking EEG rhythms since prodromal stages, which could be ascribed to poor sleep quality. We examined the relationship between wake and sleep alterations by assessing EEG activity during (NREM/REM) sleep and (pre-sleep/post-sleep) wakefulness in AD, MCI and healthy controls. AD and MCI show high sleep latency and le...

Rotating shifts (mostly 8- or 12-h) are common among nurses to ensure continuity of care. This scheduling system encompasses several adverse health and performance consequences. One of the most injurious effects of night-time shift work is the deterioration of sleep patterns due to both circadian rhythm disruption and increased sleep homeostatic pr...

Literature supports the existence of a significant relationship between sleep quality/quantity and empathy. However, empathic ability and empathic propensity are distinct constructs. Expression of empathic propensity depends on the subjective cognitive costs attributed to the empathic experience. Studies on the effects of the experimental reduction...

Increasingly, refined virtual reality (VR) techniques allow for the simultaneous and coherent stimulation of multiple sensory and motor domains. In some clinical interventions, such as those related to spinal cord injuries (SCIs), the impact of VR on people′s multisensory perception, movements, attitudes, and even modulations of socio-cognitive asp...

We have entered an era of a steep increase in the absolute and relative number of older people. This well-come phenomenon represents a major challenge for health care. However, maturational changes in sleep associated with aging do not easily appear as main factors, even though sleep alterations in the aging process lead to many detrimental consequ...

Dream research has advanced significantly over the last twenty years, thanks to the new applications of neuroimaging and electrophysiological techniques. Many findings pointed out that mental activity during sleep and wakefulness shared similar neural bases. On the other side, recent studies have highlighted that dream experience is promoted by sig...