From May 1, 2022, to May 15, 2022, we conducted a municipal-wide web-based questionnaire survey in Shanghai, China. Individuals were eligible to participate if they were currently the caregivers of a child or adolescent (aged 4 to 17 years). Data were collected through the Wenjuanxing online questionnaire platform, on which only a fully completed questionnaire can be uploaded. An invitation letter, detailing the research aim and providing a QR code automatically generated by Wenjuanxing, was issued on widely used social platforms. Snowball sampling method and convenient sampling method were used [15]. Any individual interested in the study could use the QR code and fill in the questionnaire. In addition, we have taken a number of questionnaire quality-control measures, including the following: respondent as caregiver, who should be older than 20 years old; respondents with Shanghai internet protocol addresses; each social account can only fill in the questionnaire once; and respondents who took less than 2 minutes to complete the questionnaire were excluded.

This study was approved by the Ethics Committee of Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine (Approval Number: XHEC-C-2022-043). Appropriate ethical considerations were applied during all the stages of this study. Participation in the study was entirely voluntary. The survey questionnaire was distributed among respondents who provided their informed consent on the first page and clicking on the “agree” button after reading about the purpose of the survey. The questionnaire was anonymous to ensure the confidentiality and reliability of data.

Descriptive statistics were generated for respondent characteristics and CEFIS Exposure subscale scores. Caregiver and child age, as continuous variables, were presented as median with interquartile range, and were analyzed by the Wilcoxon rank sum test. Categorical variables are presented as numbers and percentages and were compared between poor psychosocial health (PSC-17 score ≥15) and good psychosocial health (PSC-17 score <15) groups using Pearson χ² test or Fisher exact test. P values for trends were calculated using mental health as a binary categorical variable—event=PSC-17 score ≥15 (1), nonevent=PSC-17 score <15 (0)—and Pearson χ2 trend test. To further examine potential risk and protective factors for mental health, univariate and multivariate logistic regression were performed. All respondent characteristic variables were included and adjusted in the multivariate logistic regression; unadjusted odds ratios, adjusted odds ratios (aORs), and their 95% CIs were calculated. All analyses were performed with SAS 9.4 (SAS Institute, Inc) and R statistical software (version 3.6.3; R Development Core Team). Statistical significance was set at P<.05, and all tests were 2-tailed.

A total of 2540 valid questionnaires were returned. Questionnaires completed in <180 seconds were excluded, and 2493 valid questionnaires were finally analyzed. In total, 38.31% (955/2493) of the participants were male (Table 1), and 73.20% (n=1825) had 1 child (aged <18 years). In total, 52.55% (n=1310/2493) of the children were boys, and their average age was 10.99 (SD 4.18) years. Interactions with friends or peers and parents reportedly deteriorated in 64.22% (n=1601/2493) and 20.70% (n=516/2493) of the children, respectively.

The mean CEFIS score was 11.5 (SD 2.49). The scores for individual CEFIS item are summarized in Figure 1.

As shown in Table 2, the proportion of positive screening scores on the global PSC-17 scale was 16.5% (411/2493). The internalizing, attention, and externalizing problem subscales had positive screening rates of 17.3% (431/2493), 10.9% (272/2493), and 8.9% (221/2493), respectively. Caregivers’ gender, number of children (younger than 18 years old), CEFIS score, child age, child’s length of daily exposure to screens for learning and recreation during closure, length of exercise per day, sleep, interaction with friends/peers and interaction with parents compared to pre-closure were significantly associated with psychosocial problems (Table 1).

Multivariate logistic regression analysis showed that, compared with male caregivers, female caregivers were less likely to report psychosocial problems in children and adolescents (aOR 0.68; 95% CI 0.53-0.88). Older children and those with lower CEFIS scores were less likely to have psychological problems (aOR 1.15; 95% CI 1.10-1.21). Compared with children with screen times <1 hour per day for recreation, those using screens for >3 hours had higher odds of psychological distress (aOR 2.09; 95% CI 1.47-1.97). Compared with children who spent <0.5 hour exercising, those who spent 0.5-1 hour exercising had lower odds of psychological problems (aOR 0.70; 95% CI 0.52-0.94). Children who spent 1-2 hours exercising showed a trend toward lower odds of psychological problems. Children with worse sleep compared with preclosure and worse interactions with friends or peers and parents were more likely to have psychological problems (Table 3).

This study examined the impact of the COVID-19 crisis on a sample of children and adolescents in Shanghai during the lockdown in the first half of 2022. This was the first study to assess the mental health of children and adolescents using the PSC-17 in China. Nearly one-sixth (16.5%, 411/2493) of the children and adolescents were reported to be with psychosocial function problems by their caregivers, which was similar to the results of a US study [20]. In another study, 18% of urban school-age children (5-11 years old) were at risk according to the total PSC-17 score, while 18% were at risk according to the PSC-17 internalizing symptoms subscale score [19]. Given the mental health impact on children and adolescents of COVID-19 exposure, measures should be taken to help families and parents optimize child health and development [21].

Psychological problems of children and adolescents varied cross different gender of reporting caregivers. Female caregivers reported less psychosocial problems in their children. The results were similar to those by Dave et al [22] but in contrast to the findings from Hagerman [23]. Dave et al [22] reported higher scores for externalizing behaviors, such as conduct problems and hyperactivity, among children (according to their fathers). Because of the stay-at-home policy, many fathers spent more time with their children, were involved in looking after them, and were more sensitive to externalizing behaviors than mothers, who were often the primary caregivers. The results showed that older children had fewer psychological problems. A possible reason for this might be that younger children were more susceptible to the crisis situation [24]. Those caregivers who had more than one child (younger than 18 years old) reported more psychological problems of their children. The reason might be that large families with more children living in cramped conditions might be under additional stress, including parenting-related stress, abuse, violence against children [25], and an increased risk of COVID-19 infection [26]. Government and community efforts are needed that target those at-risk households.

COVID-19 exposure was a risk factor for psychological problems of children and adolescents. The results of our study indicated severe COVID-19 exposure in our sample and increased risks of psychological problems. To eliminate COVID-19, stringent measures were implemented in Shanghai. Transport restrictions resulted in inconvenience in everyday life. Schools were closed, and children’s education was disrupted. Everyone, except essential workers, had to stay at home. Some families had difficulty obtaining essentials such as food, medicine, health care, and so on. Moreover, the shutdown had economic repercussions for many families, such as decreased income or unemployment. The infected families and those in which someone was serving as an essential worker outside the home had more difficulties with parenting and meeting the growth and developmental demands of their children. Government and community efforts are needed that target at-risk households. Children who are separated from their caregivers also require particular attention, including those infected with or suspected of being infected with COVID-19, those who are quarantined in local hospitals or medical observation centers, and those whose caregivers are infected with COVID-19 [27].

In this study, the rate of psychosocial problems increased with recreational screen time, consistent with other studies [28]. School closures and strict containment measures have led to more families relying on technology and digital solutions for their children’s learning, entertainment, and connection to the outside world [28,29]. Many children and adolescents are spending more time online, allowing for social interactions in some cases but also increasing the risk of cyberbullying, cybercrime, privacy infringements, and screen fatigue [10,30,31]. It has been proved that cyberchondria partially mediated the relationships between perceived severity of the COVID-19 pandemic and depression, anxiety, and stress in China [32]. As screen time increased, so too did sedentary behavior [33], which was associated with poor behavioral conduct or prosocial behavior and reduced sleep duration [34,35]. Worse sleep was a risk factor for the development of psychosocial problems in our study. Therefore, for children and adolescents, the time spent being sedentary should be limited, particularly the amount of recreational screen time [36]. Mutually agreed rules, limits, and parental monitoring of screen time were perceived as likely to be effective [37]. Interactive games and exercises can serve as a supplement for filling the time previously spent on screen.

Children and adolescents who spent 1-2 hours exercising showed a trend toward lower odds of psychological problems, and exercise for less than 30 minutes per day had a high probability of psychosocial problems. Psychosocial problems were linked to lower levels of physical activity [38-40]. Greater levels of physical activity are associated with improved physical fitness, bone health, cognitive outcomes, and mental health (reduced symptoms of depression) and less adiposity [36]. The World Health Organization recommends that children and adolescents perform at least 60 minutes of moderate-to-vigorous–intensity (mostly aerobic) physical activity per day. Vigorous-intensity aerobic activities, as well as those that strengthen muscle and bone, should be performed on at least 3 days a week [36]. High-quality physical education and supportive environments can promote physical and health literacy for long-lasting, healthy, active lifestyles [41]. Special attention should be paid to long-duration exercise. Previous studies had showed exercise durations of >3 hours were associated with worse mental health than exercising for 45 minutes [42]. In this study, exercise durations of 30 minutes to 1 hour were shown to be better for the psychosocial function of children and adolescents. Moreover, excessive exercise might cause fatigue and worsen mental health of children and adolescents [43].

In total, 27.9% of the caregivers reported that their interactions with children improved, which was significantly associated with lower positive screening scores. The stay-at-home policy might promote stronger relationships of children and adolescents with their parents [25] and has shown to improve their mental health [44]. Previous studies have reported that parent-child activities and exercises together can improve interactions between caregivers and children and amplifies the beneficial effects of sleep on mental health [45]. For example, mindfulness-promoting exercises (ie, yoga and tai chi) could be performed indoors by parents and children together [42]. In total, 64.2% (1601/2493) of the children and adolescents reported worse relationships with friends and classmates, and these children and adolescents were more likely to have poor mental health. There is an urgent need to increase the social interactions of children and adolescents during lockdown. Communities could redesign neighborhoods to provide children with spaces to play together and enjoy interactions [10]. Studies have shown that digitalized social contact can mitigate the potentially harmful effects of physical distancing on young people [9]. Specifically, active use of social media, for example, engaging in direct communication (ie, messaging) or posting directly on another person’s social media profile, can increase well-being and help maintain personal relationships. Time-limited and active use of social media for contact with peers might be beneficial for the mental health of children and adolescents.

This study had several limitations. First, its cross-sectional nature limits the ability to establish a causal relationship between risk factors and mental health. Furthermore, there were no preclosure PSC-17 data for Chinese children and adolescents, so we could not determine whether the psychosocial problems detected in the participants were intensified during COVID-19 exposure. Second, the data were collected online because of the COVID-19 pandemic, and caregivers whose lives were severely disrupted and had limited time online might have been less likely to finish the questionnaire. Third, data for the main variable of interest, psychosocial functioning, were obtained from caregivers of the children and adolescents, which may cause bias. When compared to self-report or direct observation of youth behaviors, caregiver report may not be as accurate.

In this cross-sectional study conducted during a wave of COVID-19 infection in Shanghai, in which stringent responses were implemented, we found that the prevalence of psychosocial problems among children and adolescents was relatively high. Daily life of the children and adolescents changed a lot, including screen time, exercise, sleep, and interaction with parents and peers. Younger children, more COVID-19 exposure, more recreational screen time, and worse sleep were risk factors for poor psychosocial functioning. In particular, exercise durations of 1-2 hours and better interactions with friends or peers and parents benefit the psychosocial function of children and adolescents. The findings suggest that it is necessary for governments, communities, schools, and families to take appropriate countermeasures to reduce the impact of the lockdown measures on daily life and its subsequent influence on mental health of children and adolescents, which can be provided as suggestions on maintaining the mental health when similar public health emergencies occur in the future, leading to the stringent lockdown. In addition, it will be necessary to conduct longitudinal studies to clarify whether psychosocial problems are reduced, maintained, or intensified over time, as well as to identify subgroups of young people most at risk.