To our knowledge, this is the first study describing variations of sleeping patterns and emotionality during the Covid-19 pandemic in adolescents with AN. Considering sleeping patterns, findings of the current study revealed increased insomnia severity and a tendency for longer sleep latency and later wake time associated with the pandemic period. This finding is in line with prior research carried out on the adult general population during the quarantine period, mainly showing a decrease of sleep quality , ,  and an increase in insomnia rate and severity , . Some studies in adults  and adolescents ,  also described significant changes in sleep timing, with later bedtime and wake up time, confirming our data. However, contrary to the previously mentioned studies, we did not find an increase in sleep duration in our sample of adolescents with AN. The absence of this protective factor  and the finding of increased sleep difficulties in people with higher levels of depression, anxiety and stress symptomatology , may instead be related to raising fears of long-term consequences on mental health of adolescents with AN in the course of their disease. Indeed, it has been suggested that sleep alterations, and particularly insomnia, may persist after an acute stress phase and are often precursors of psychiatric disorders and suicide in adults , . In adolescents, the increased risk of psychiatric disorders, such as depression, and substance use, has been associated with a worse regulation of risk-taking behaviors, and with potential negative impacts on school performance as well , . Other studies suggest that sleep alterations are precursors and severity markers in AN –. Although our study did not find a significant augmentation in AN severity during the pandemic, the significantly ascending evolution kinetics of insomnia and the sleep alterations observed throughout this period may raise fears of an increase in the incidence and severity of these adolescents in the coming months. Sleep quality seem to highly relate to emotionality, in particular, poorer sleep is strongly associated to diminish experiencing positive emotions , which could explain the increased sleep disturbances found here.
In line with the study Lin and colleagues , our findings also revealed, more than an increase in negative emotions, a significant decrease in the experience of positive emotions in adolescents with AN during the pandemic, especially emotions of joy and tenderness. So far, research on Covid-19 pandemic essentially showed an increase in negative emotions , , while its impact on positive emotions in youth with AN is still limited . The same trend is found in the literature regarding the interaction between sleep and emotionality, with the influence on positive emotions being largely unexplored. Few studies however found sleep duration to be positively associated with happiness, and that lower sleep quality is associated with unhappiness , .
According to the positive psychology framework, positive emotions such as joy, not only are necessary for managing present challenges such as a pandemic period, but they also build resilience crucial for managing future adversity. Positive psychology suggests that patients may be able to change their behaviors and broaden their perception when experiencing some degree of positive emotion. This effect could have important implications for EDs, as there is experimental evidence suggesting patients have cognitive inflexibility and attention to detail rather than the big picture . Therefore, facilitating positive emotional states and broadening problem-solving skills seem highly relevant to aid individuals with ED . Given the negative impact of the pandemic on these two related clinical variables in AN (sleep and positive emotionality) and on the ascending evolution kinetics of these difficulties throughout this period, knowledge about interventions targeting these aspects and decrease the impact of Covid-19 at a short, medium and long-term, seem fundamental for clinicians –.
To reduce sleep alterations, sleep health education and sleep hygiene should be the first priority to prevent long-term adverse outcomes associated with chronic insomnia and mental health problems . Sleep hygiene refers to ensuring bright light exposure during the day but not during the night to enhance sleep-inducing melatonin production, not drinking caffeinated coffee or tea in the evening, reducing alcohol intake, not exercising immediately prior to bedtime, avoiding clock-watching during the night, and ensuring an optimal room and body temperature to fall asleep. For patients with chronic insomnia, the Cognitive and Behavioral Therapy for Insomnia (CBT-I), the first-line treatment for insomnia, should be made more widely available , . The key elements of this effective insomnia treatment are sleep hygiene, stimulus control; relaxation interventions; cognitive reappraisal (challenging and replacing dysfunctional ideas about sleep problems and its causes); paradoxical intention (asking individuals to try to stay awake instead of trying to fall asleep), and sleep restriction (restricting the time spent in bed based on the individual's average current nightly sleep duration). Mindfulness, the practice of paying attention to the present moment, purposefully and nonjudgmentally, has been gaining popularity as adjunct treatment for adults and adolescents with a range of physical and mental health problems. Mindfulness-based interventions show promising results in various areas including the treatment of sleep disorders in adolescence , , and CBT-I shows promising effects also for children and adolescents .
The Covid-19 pandemic is an unprecedented, traumatic event significantly affecting the mental health of people with ED, possibly through the exacerbation of emotion regulation difficulties. The findings of the current study may further provide clues to a model to guide clinicians in the management of AN patients, suggesting the therapeutic need targeting the antecedents that trigger negative emotions, such as sleep troubles, and increase therapeutic interventions that enhance positive emotions , such as reappraisal strategies. The positive psychology frameworks support the development of mental health strategies that focus on promoting competence, resilience, and a sense of efficacy, at both individual and collective levels. Consistent with this, adaptive emotional coping strategies, such as reappraisal, can be an important resilience factor in reducing the negative impact of the pandemic . While shedding light on the link between sleep and emotionality in AN in this particular context, this study presents several limitations. The design did not allow us to confirm the potential causal links between sleep disturbances, emotionality, mental health, and severity of AN in our sample of adolescents. Although using standardized and reliable measures, the lack of more objective measures of sleep would allow us to confirm and specify subjective sleep disturbances. In conclusion, this study confirmed that sleep disturbances are associated to emotionality in adolescents with AN, in particular regarding the Covid-19 pandemic. The impact of these disturbances on global mental health and AN severity, well established in the literature, leads us to emphasize the importance of their management using valid and effective tools. This encourages further research on the effectiveness of therapeutic tools such as CBT-I, mindfulness based-interventions and reappraisal strategies in AN, consistent with the positive psychology framework. This perspective may be successfully incorporated into crisis response and recovery phases of disaster mental health efforts to address the need of adolescents suffering from AN, which seems particularly urgent given the trend confirmed from our data, and which is likely to continue long after the acute phase.