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Impacts of COVID-19 on children and adolescents: A systematic review analyzing its psychiatric effects

OBJECTIVE To summarize the most relevant data from a systematic review on the impact of COVID-19 on children and adolescents, particularly analyzing its psychiatric effects. METHODS This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and included experimental studies (randomized-individually or pooled-and non-randomized controlled trials), observational studies with a group for internal comparison (cohort studies-prospective and retrospective-and case-control) and qualitative studies in the period from 2021 to 2022. RESULTS The search identified 325 articles; we removed 125 duplicates. We selected 200 manuscripts, chosen by title and selected abstracts. We excluded 50 records after screening titles and abstracts, as they did not meet the inclusion criteria. We retrieved 150 records selected for a full reading. We excluded 90 text articles and we selected 25 records for the (n) final. Limitations: Due to the short period of data collection, from 2021 to 2022, there is a possibility of lack of relevant studies related to the mental health care of children and adolescents. In addition, there is the possibility of publication bias, such as only significant findings being published. CONCLUSION The impact of COVID-19 on the mental health of children and adolescents is of great concern to child and youth psychiatry. Situations such as fear, anxiety, panic, depression, sleep and appetite disorders, as well as impairment in social interactions caused by psychic stress, are punctual markers of pain and psychic suffering, which have increasing impacts on the mental health panorama of children and adolescents globally, particularly in vulnerable and socially at-risk populations.


INTRODUCTION
The outbreak of coronavirus disease 2019 (COVID-19) has caused pain and psychological suffering in children and adolescents, particularly considering the new variants of the disease [1]. Psychologically stressful situations are the main effects caused to populations under the influence of COVID-19, which can contribute to the development of post-traumatic stress symptoms, especially for vulnerable children/adolescents (C-A) in critical developmental stages, with variable prevalence, risk factors, and severity [2]. Recent studies highlight that C-A are more likely to have high rates of depressive or anxiety disorders, impairing family, school, cultural, and social interactions, with multiple and adverse consequences to mental health in the medium and long term [3,4].
Current studies have observed that parental stress, co-parenting, emotional well-being, and children and adolescents' adjustment were impacts that acted unfavorably in the COVID-19 pandemic [5,6]. These findings highlight the psychic burden and stress faced by caregivers of C-A with disabilities and compromised psychiatric development during the pandemic.
In this context, C-A with neurodevelopmental disorders (NDD) have higher levels of distress compared to typically developing children. Distress levels may be heightened by restrictions associated with the COVID-19 pandemic [7,8]. Parents' perceptions of how the pandemic has mitigated their mental health have implications for their well-being and that of their children, with a stronger association for low-income families [9].
Although parenting is essential for positive development, increased parental distress interferes with children's well-being. Sesso et al [10] warn that internalization problems in C-A with NDD were among the strongest predictors of parental stress during the pandemic lockdown. The dysfunctional interactions of a child are usually mediated by their internalizing/externalizing problems [11,12]. In this context, parents of children with NDD should be valued groups in public policies to promote mental health in the post-pandemic period [13].
It is also important to highlight that the prevalence of anxiety generally varies from 19% to 64% and depression from 22.3% to 43.7% among adolescents. Among children aged 5 to 12 years, the prevalence of anxiety ranges from 19% to 78%, while depression among adolescents ranges from 6.3% to 22.6% [14]. Among preschool-age children, some studies have found that behavioral and emotional problems worsen during the pandemic [4,15].
This paper aims to summarize the most relevant data on the impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic on C-A through a systematic review, particularly analyzing its psychiatric effects.

METHODS
A systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) protocol from 2021 to 2022. Qualitative studies, quantitative studies (e.g., prospective/retrospective cohorts, case-control studies), and experimental studies (randomized, pooled or individual, and non-randomized controlled trials) were included. Case reports, case studies, opinions, editorials, letters, and conference abstracts were excluded.

Search strategy
We searched the Web of Science Index Medicus, MEDLINE, WHO COVID-19 databases, EMBASE, Scopus, and Cochrane Library. Non-indexed databases, including MedRxiv preprint and Google Scholar, were also used. To identify missing documents, all systematic reviews and relevant comments were manually searched.

Types of participants
Studies on children and adolescents aged 3 to 19 years from 2021 to 2022, and which focused on psychiatric interventions in children and adolescents during the SARS-CoV-2 pandemic were included.

Selection of studies
Articles were included only if the study exclusively examined the mental health impacts of COVID-19 on children and adolescents from 2021 to 2022. Detailed inclusion and exclusion criteria are shown in Table 1. Using Covidence, a web-based tool that helps to identify studies and involves data extraction processes, two reviewers (MLRN and JPP) independently examined all potential articles. In the case of disagreement, both reviewers read the article and discussed it until a consensus was reached.

Data extraction
Relevant data were extracted from each study, including year and country of publication, study design, target population, pandemic exposure, interventions, and outcomes ( Table 2). One reviewer (NNRL) used a form that the research team developed to extract the data. A second reviewer (AOAR) verified the entire data extraction activity and verified its accuracy and completeness. Disagreements were resolved through discussion.

Quality assessment
The methodological quality of the studies was assessed using the Mixed Methods Assessment Tool.

Data analysis/synthesis
Data were aggregated and analyzed according to the results and objectives of the study. Therefore, the results were summarized according to the reported results and the study design (Table 2).

Risk of publication bias
The likelihood of a treatment effect reported in systematic reviews resembling the truth depends on the validity of the studies included in the analysis as certain methodological characteristics may be associated with effect sizes. Therefore, it was important to determine in the systematic reviews whether the sample of studies obtained was representative of all the research carried out on depression in childhood and adolescence in times of COVID-19. The possibility of bias resulting from a trend of only positive findings being published-known as the "file drawer effect"-was addressed using two methods: Calculating the fail-safe N and the p-curve approach. The fail-safe N is determined by calculating the number of studies with a mean null result needed to make the overall results insignificant. The p-curve was introduced to account for "p-hacking", a theory stating that researchers may be able to get most studies to find positive results across different reviews. The p-curve assesses the slope of the reported p-values to determine whether p-hacking has occurred.
The most significant findings of depression in children and adolescents impacted by COVID-19 were found in 24 studies, which required the p-value to be set at > 0.05. In addition, quarantine, sleep disturbances, post-traumatic stress symptoms, and the prevalence of anxiety were findings that validated the results. The p-curve was applied to explain p-hacking-to guarantee positive results. When calculating the p-curve, only 13 studies were included that examined the psychiatric impact on adolescents and children during the COVID-19 pandemic [2,3,6,7,[15][16][17][18][19][20][21][22][23]. The studies existing in the literature (P = 0.5328) indicating depression among children and adolescents have sufficient evidence in their findings, particularly because there were 11 studies on potential interventions to improve the mental health of children and adolescents [1,4,5,8,[9][10][11][12][13]23,24].
Clearly, solutions to the file drawer problem present an irritating and challenging issue for metaanalytic research and it will likely take a paradigm shift to truly address this problem, as authors who submit their literature reviews and methods only, abandoning conventional inferential statistics in favor of Bayesian Approaches, or the registration of studies and protocols online before conducting a study.

RESULTS
The search identified 325 articles, but 125 duplicates were removed. Therefore, 200 articles were selected, chosen by the title and abstract. Fifty articles were excluded after screening the titles and abstracts, as they did not meet the inclusion criteria. Consequently, a total of 150 articles were selected to be read in full. After that, 91 text articles were excluded, with 24 being selected for the final (n) (Figure 1).

Study results
We analyzed the studies thematically and divided them into two categories: (1) Psychiatric impact on children and adolescents in times of COVID-19; and (2) potential interventions to improve the mental health of children and adolescents.
A research study by Demaria and Vicari [2] and Sayed et al [3] showed that quarantine is a psychologically stressful experience. For children, missing school and interruptions in daily routines can have a negative impact on their physical and mental health. In this perspective, they pointed out that parents

Figure 1 Diagram of preferred reporting items for systematic reviews and meta-analyses (PRISMA).
could also pass on their psychological suffering to children and parent them inappropriately, contributing to the development of post-traumatic stress symptoms. In addition, if the C-A has a mental disorder, the psychic suffering of the parents tends to be greater and depends on the way children externalize their emotions [6,7]. Minozzi et al [14] highlight high rates of anxiety and depression among C-A. Among preschool children, they found aggravation of behavioral and emotional problems, while others did not. They found that psychological well-being had significantly worsened, especially among adolescents. Backer et al [15] demonstrate that the reduced number of social contacts associated with strict social distancing measures contributes to inflicting pain and psychic suffering in children and adolescents. The authors also point out that not wearing a mask; being a high school student [15] and spending less than 0.5 h exercising were positively associated with increased psychological distress [16].
A meta-analysis of 23 studies (n = 57927 children and adolescents from Turkey and China) showed combined prevalence of anxiety, post-traumatic stress symptoms, sleep disorders and depression. In addition, female sex and adolescents were more associated with depressive and/or anxious symptoms when compared to male sex or children, respectively[18].
Barros et al [19] showed high rates of nervousness (48.7%) and sadness (32.4%) among Brazilian adolescents. Individuals aged between 15-17 years; being female; having learning difficulties during the pandemic; having a family that faces financial difficulties; and individuals who previously had trouble sleeping or poor health were the most affected. In the study by Han and Song [20] economic difficulties during the pandemic were correlated with depression and suicidal ideation. Concerning their emotions, adolescents recognized anxiety about self-harm and harm to their loved ones, as well as mood swings in the family nucleus [21].
Globally, the increase in drug abuse has also been mapped in the literature, with alcohol and marijuana being the most used [7]. Almhizai et al [22] showed that the older age of children and adolescents was a risk factor for sleep disorders, malaise, and nervousness. The presence of a relative infected with COVID-19 was also associated with higher rates of anxiety, irritability, sadness, and sleep disorders. Finally, physical punishment and verbal threats had a more negative impact on the mental health promotion of C-A when compared to the pre-pandemic period.
Bussières et al [5] showed no association between the presence of previous chronic diseases (including NDD) and negative symptoms during the pandemic. Raffagnato et al [8] highlight that patients with internalizing disorders had better adaptation and lower rates of psychological distress when compared to patients with psychological distress.
In addition, the worsening of parents' mental health [10], school-age children belonging to urban racial and ethnical minorities [23], and physical inactivity [1,17] had a negative impact on the health of children and adolescents. Data from Li and Zhou[11] suggest that children less exposed to parental concerns (e.g., about finances, health and education) were less likely to have internalizing and externalizing problems [11]. It is crucial to promote family well-being through political practices and initiatives, including providing financial and care assistance to parents and supporting the mental and behavioral health of families [9]. In addition to focusing on symptom management, families can benefit from support aimed at the parent-child relationship. Insights and implications for practitioners are discussed [12]. Finally, promoting coping strategies for children and adolescents to deal with extreme situations (e.g., pandemics, wars, and natural disasters) is fundamental. Especially if the strategies encompass the communities/schools the children/adolescents attend[24].

DISCUSSION
The rapid spread of COVID-19 has significantly influenced the psychological state of children and adolescents. It is clear that poverty [19,20], hunger, housing insecurity, domestic violence, and sexual abuse [19], black children and adolescents, and homeless people living in favelas, especially older adolescents, need urgent mental health support. The physical restrictions of the COVID-19 pandemic and the social distancing measures have affected all domains of life. Anxiety, depression, drug abuse, sleep and appetite disorders, as well as impaired social interactions, are the most common presentations [4,13].
The frequency of mask use and time spent on schoolwork were factors associated with good mental health [16]. The prevalence of depression ranges from 13.5% to 81.0%. Analysis by age indicated that the prevalence of depression is higher in children aged 5-9 years and adolescents aged 12-18 years. Analysis by gender showed that the prevalence of depression in females was higher than in males. The prevalence of anxiety among children and adolescents was 45.6%. The prevalence of post-traumatic stress symptoms is statistically higher in vulnerable and/or socially at-risk children and adolescents. The prevalence of sleep disorders varies according to the stressor involved in family ties and the way they face COVID-19, as well as the economic situation and the healthcare system, which vary greatly between countries [17]. Parental anxiety has the greatest influence on a child's psychological symptoms, explaining about 33% of the variation in a child's overall symptoms [18,23].
Most studies point to negative symptoms being caused by social distancing in children and adolescents of vulnerable families, including restrictions on social life and personal freedom, as well as excessive contact with family members during stay-at-home periods [1,2,21].
It is important to highlight that children and adolescents in extreme poverty report a wide range of negative thoughts associated with the pandemic (for example, abandonment, helplessness, sadness, anguish, anxiety, and feelings of panic). The thoughts and feelings of such teenagers can be triggered by the fact that their survival is threatened [4,5].
Special populations, especially lesbian, gay, bisexual, transgender, and queer (LGBTQ) adolescents, have higher rates of pain and psychological distress that lead to anxiety, depression, compulsion, and post-traumatic stress disorder (PTSD). Additionally, coming into conflicts with parents due to gender issues is observed in the literature as a factor that worsens mental health in this population [7,22].

LIMITATIONS
Due to the short data collection period, from 2021 to 2022, relevant studies on how to care for the mental health of children and adolescents may be lacking. In addition, there is the possibility of publication bias, i.e., only significant findings being published.