The restraining measures due to the COVID-19 outbreak deeply affected the general population’s sleep health and psychological status. The current literature proposes young and older people as two particularly at-risk groups. However, the differential impact of the lockdown period in these specific age categories needs to be disentangled. Through a web-based survey adopting validated questionnaires, we evaluated and compared sleep quality/habits, insomnia, perceived stress, depression, and anxiety symptoms of Italian late adolescents (n = 670; mean age ± SD, 19.38 ± 0.74, 18–20 years) and elderly (n = 253; 68.18 ± 2.79, 65–75 years). Young respondents reported more severe insomnia symptoms, worse subjective sleep quality, longer sleep latency, higher daytime dysfunction, and a more prevalent disruption of sleep habits (bedtime, get-up time, nap) than the elderly. On the other hand, older participants showed shorter sleep duration, lower habitual sleep efficiency, and greater use of sleep medications. Finally, the younger population displayed higher levels of depression and perceived stress. Our findings indicate that the lockdown period had more pervasive repercussions on sleep and the mental health of late adolescents. The implementation of supportive strategies is encouraged for this vulnerable population group.

The COVID-19 pandemic led world authorities to adopt extraordinary measures to counteract the spread of the virus. The Italian government established a national lockdown from 9 March to 3 May 2020, forcing people in their homes and imposing social distancing. During the pandemic emergency, university students emerged as a vulnerable category. Indeed, higher rates of sleep problems and mental disorders were reported in this population. However, these outcomes were derived from cross-sectional investigations adopting retrospective assessments. Retrospective evaluations suffer from different biases, putatively leading to erroneous outcomes. To overcome this limitation, we adopted a between-subject approach comparing a sample of 240 Italian undergraduate university students assessed in 2016 (mean age ± standard deviation, 20.39 ± 1.42, range 18–25; 80.42% females), with an age/gender-matched sample of university students assessed during the third week of lockdown in Spring 2020. We evaluated sleep quality, insomnia symptoms, and depressive symptomatology using validated questionnaires. We found worse sleep quality, a delayed bedtime, and more severe insomnia and depression symptoms in the students sampled under COVID-19 restrictive measures. We suggest paying special attention to this at-risk population during the current pandemic emergency and applying preventive and supportive interventions to limit the exacerbation of sleep and psychological problems.

Rapid eye movement sleep is believed to reduce physiological reactivity to emotional experiences. While rapid eye movement sleep fragmentation has been associated with maladaptive emotional processing in clinical and animal models, its causal role has not been experimentally isolated in healthy humans. In this study, we tested whether selectively fragmenting rapid eye movement sleep impairs overnight psychophysiological habituation in healthy individuals, aiming to identify the cortical dynamics involved. Seventeen participants (mean age ± SD, 23.18 ± 3.94, 14 females) completed two counterbalanced conditions (fragmentation and control) each encompassing a baseline assessment of emotional memory/reactivity, a nocturnal polysomnography with or without wrist-applied vibrotactile stimulation during rapid eye movement sleep, a post-sleep emotional memory/reactivity reassessment, and a 48-h follow-up evaluation. Emotional memory was evaluated using an old/new paradigm, while emotional reactivity was assessed through self-report and physiological measures (electrodermal activity and heart rate deceleration–heart rate deceleration). The stimulation procedure elicited cortical arousal during rapid eye movement sleep, increasing rapid eye movement sleep fragmentation without altering total sleep time, sleep efficiency, and wake after sleep onset. Stimulations reliably induced a distinct cortical arousal signature, characterized by increased higher EEG frequencies (alpha, sigma, beta, gamma). rapid eye movement sleep fragmentation compromised heart rate deceleration habituation to emotional stimuli at both post-sleep assessments without impacting electrodermal response, self-report evaluation, and recognition memory. Crucially, the degree of impaired cardiac habituation at both timepoints was strongly predicted by the magnitude of stimulation-induced alpha power over parieto-occipital regions. These findings indicated the importance of unperturbed rapid eye movement sleep continuity for proper psychophysiological habituation to emotional events, suggesting alpha intrusions as a potential cortical correlate of impaired habituation.

Emotion reactivity refers to the activation, intensity and duration of emotional responses to internal or external stimuli. It can be differentiated from emotion regulation since the former is the very first response to an emotional trigger, and the latter can be defined as a tool for maintaining one's arousal in a window of tolerance. Since, to date, there are no Italian self‐report measures able to evaluate individuals' emotional reactivity, this study aimed to contribute to the Italian validation of the Perth Emotional Reactivity Scale–Short Form (PERS‐S). The PERS‐S is an 18‐item self‐report measure answered on a 5‐point Likert scale that generates six subscale scores and two composite scores, with higher scores indicating higher levels of reactivity. Data from 768 individuals showed that the PERS‐S had good to excellent goodness of fit. The internal consistency was high, with an overall reliability coefficient (Cronbach's α) of .87 and .86 for the negative and positive general scales, respectively. The PERS‐S also demonstrated appropriate convergent validity, showing significant correlations with conceptually related measures, and acceptable divergent validity, showing minimal correlations with unrelated constructs. Finally, we evaluated the Test–Retest Reliability by administering the PERS‐S to the same sample twice, with a 2‐week interval. The significant correlations between the two PERS‐S administrations suggest temporal stability. The Italian version of the PERS‐S will enrich the repertoire of self‐report measures for investigating the development and risk factors of mental health disorders and may have practical applications in clinical settings.

Summary: Targeted memory reactivation represents an established technique for promoting sleep‐dependent memory consolidation in laboratory studies. This investigation aimed to test the potentiality of a wearable electroencephalography‐based closed‐loop targeted memory reactivation system to boost vocabulary learning in home settings. In the evening, 24 adults (23.58 years ± 3.36 years, 19 females) were asked to learn the Italian translation of 40 pseudowords (test session). Subsequently, participants slept at their home wearing an electroencephalography headband (Dreem 2), and half of the pseudowords were acoustically re‐presented (cued) following the real‐time detection of slow waves. After the awakening, memory recall of the Italian translations was retested. The stimulation effect was evaluated by comparing the test–retest variations in memory accuracy between cued and uncued pseudowords. Moreover, we assessed the event‐related potentials and spectral perturbations induced by the cued stimuli during sleep, comparing the electrophysiological correlates of correctly translated pseudowords with incorrectly translated ones at the retest session. Closed‐loop targeted memory reactivation increased the translation accuracy for cued pseudowords (+8.6%), while no significant test–retest variation for uncued items was observed (−4.6%). Time–frequency analysis indicated a spectral power increase in the spindle frequency band coinciding with the second positive peak of the sound‐elicited slow wave as the correlate of successful morning recall. This study extended the targeted memory reactivation effectiveness in enhancing vocabulary learning to an ecological home environment, providing further support to the role of spindle activity in the targeted memory reactivation effect. A wearable closed‐loop targeted memory reactivation system could represent a memory‐enhancement tool in real‐world settings by promoting the hallmark sleep electroencephalographic rhythms of memory consolidation.

Background and aims Eveningness is distinctively associated with sleep disturbances and depression symptoms due to the misalignment between biological and social clock. The widespread imposition of remote working due to the COVID-19 pandemic allowed a more flexible sleep schedule. This scenario could promote sleep and mental health of evening-type subjects. We investigated the effect of working from home on sleep quality/quantity and insomnia symptoms within the morningness-eveningness continuum, and its indirect repercussions on depressive symptomatology. Methods 610 Italian office workers (mean age ± standard deviation, 35.47 ± 10.17 yrs) and 265 remote workers (40.31 ± 10.69 yrs) participated in a web-based survey during the second contagion wave of COVID-19 (28 November–11 December 2020). We evaluated chronotype, sleep quality/duration, insomnia, and depression symptoms through validated questionnaires. Three moderated mediation models were performed, testing the mediation effect of sleep variables on the association between morningness-eveningness continuum and depression symptoms, with working modality (office vs. remote working) as moderator of the relationship between chronotype and sleep variables. Results Remote working led to delayed bedtime and get-up time. Working modality moderated the chronotype effect on sleep variables, as eveningness was related to worse sleep disturbances and shorter sleep duration only among the office workers. Working modality moderated the mediation of sleep variables between chronotype and depression. The above mediation vanished among remote workers. Conclusions Remote working strikingly abolished the vulnerability to sleep problems of evening-type subjects, relieving their predisposition to depressive symptomatology. A working environment complying with individual circadian preferences might ensure an adequate sleep quantity/quality to late chronotypes, promoting their mental health. Statement of Significance The present study is the first to evaluate the different effect of pandemic-related remote working on sleep health/habits depending on the chronotype. We found longer sleep duration and improved sleep disturbances among evening-type subjects when working from home. This outcome could be ascribable to a better alignment between the endogenous circadian phase and the working schedule, as remote workers reported later bedtimes and get-up times. Moreover, we showed how improved sleep weakened the susceptibility to depressive symptomatology of evening-type people, highlighting an intriguing implication of working remotely on mental health in this category. Morningness-eveningness predisposition should be considered when designing remote working policies, in order to promote sleep and mental health of late chronotypes during the pandemic emergency, as well as in the post-covid era.