Table 2.

Summary of descriptive characteristics of the included studies according to main Data

Author Year/country Type of study	Target population and sample size	Screen type used	Types of behavioral disorders	Questionnaire	Finding
HUA CHEN et al., 2021,[11] Taiwan A longitudinal study	primary school students’ mean age was 10.32 years (n=535; 265 boys)	1. Smartphone 2. Social Media 3. Internet Gaming	Psychological distress (Depression, Anxiety, Stress)	DASS-21	Schoolchildren who increased their by 15 or 30 min daily on internet-related activities showed an increased level of psychological distress
Lin Wang et al., 2020, China[30] A cross-sectional study	Children (6-11 years old) and adolescents (12-16 years old). n=12186	Videogames	Psychosocial and behavioral problems	the Achenbach Child Behavior Checklist (CBCL).	The positive detection rate of psychological problems within Wuhan was greater than that outside Wuhan for schizoid, and depression in children, and for somatic complaints, immaturity, and delinquent behavior.
Chao Chen et al., 2019, China[15] A longitudinal study (Perspective)	Children (Mean [SD] age=10.83 [0.75] years) n=575	1. Smartphone Application 2. Internet Gaming	Psychological Distress	DASS 21, Smartphone Application-Based Addiction Scale	Cross-lagged models found that higher levels of problematic smartphone use were not significantly related prospectively to greater psychological distress before the COVID-19 outbreak, but this prospective relationship became significant during the COVID-19 outbreak.
			Problematic gaming	(SABAS), Internet Gaming Disorder Scale-Short Form	Whereas problematic gaming was associated prospectively with psychological distress before the COVID-19 outbreak (between Waves 1 and 2), this association became nonsignificant during the COVID-19 lockdown (between Waves 2 and 3).
Rita Monteiro et al., 2020, Portugal[31] A Cross-Sectional Study	Children aged from 6 months to 6 years, n=193	Exposure time (in hours) to television, cellphone, and Internet,	Behavioral and emotional symptoms on children	Baby Pediatric Symptom Checklist (BPSC), Preschool Pediatric Symptom Checklist (PPSC), Question about time use of screen time exposure	The findings revealed a modest relationship between children’s exposure time to screens and behavioral and emotional problems on children studied. It was also found that parents may play an important role in children’s behavioral and emotional adjustment during the confinement period.
Lisa S. Olive et al., 2020, Australi[10] A cross-sectional Study	n=2365, children aged ≤18 years,	Screen time	Mental health	DASS 21	Children’s sleep problems were significantly associated with increased mental health problems after accounting for socioeconomic status, physical activity, and screen time and Children more using screen time on the weekend.
Xuedi Li et al., 2020, Canada[32] A Cohort Study	Aged 2–18 years, n=2026	TV and digital media time, video games, electronic learning time, and video chatting time.	Depression-anxiety, conduct problems, Strengths and Weaknesses of Attention-Deficit/Hyperactivity Disorder (SWAN Symptoms and Normal Behavior Scale)	Strengths and Difficulties Questionnaire (SDQ), depression and anxiety), RCADS-P (Revised Children and Depression Scale–Parent Version) for older children, SCARED (Screen for Child Anxiety Related Disorders, TIDES (The Irritability and Dysregulation of Emotions questionnaire) was administered to measure. irritability	higher TV or digital media time was associated with higher levels of conduct problems and hyperactivity/inattention, higher levels of depression, anxiety, and inattention; higher levels of video game time were associated with higher levels of depression, irritability, inattention, and hyperactivity. Higher levels of electronic learning time were associated with higher levels of depression and anxiety.
Chika Ueno et al., 2020, Japan[33] A cross-sectional Study	959 children in four public elementary schools.	screen time	Behavioral problems	Self-administrative questionnaire	Time of spending on TV and/or video and video games significantly longer during school closure than after school reopened. children’s behavioral problems during school closure were associated with longer total screen time (OR: 1.2, 95%, [CI]: 1.14–1.28, P<0.001).
Brae McArthur et al., 2021, Canada[34] A cross-sectional Study	n=846, (child age 9–11)	Screen time	Depression-anxiety	Depression Short Form (CES-D-10), 6-item Spielberger State Anxiety Inventory Short Form (SSAI-SF)	After controlling for child sex, age, and anxiety symptoms pre-COVID-19, connectedness to caregivers and child sleep were negative, and child screen time duration positively predicted anxiety. Depressive symptoms pre-COVID-19, connectedness to caregivers were negative, and child screen time duration was significantly predicting depressive symptoms.
Li Duan et al., 2020, China[35] A cross-sectional	359 children and 3254 adolescents online	smartphone addiction, Internet Addiction	Depression	Spence Child Anxiety Scale, Child Depression Inventory, and Coping Style Scale	Seven significant factors associated with increased levels of anxiety, including female, resident in urban regions, and emotion-focused coping style. Nine factors are associated with increased levels of depression, such as smartphone addiction, Internet addiction, and residence in Hubei province. Two additional factors are associated with decreased levels of depressive symptoms: hours spent on Internet per day before the epidemic and the tendency to apply a problem-focused coping style.
Michelle Drouin et al., 2020, USA[36] A cross-sectional study	(n=260), children aged 0–19 years	social media, phone	Anxiety	Parent anxiety (PHQ-4) and other self-administrative questionnaire	On average, parents reported that both they and their children (especially teenagers aged 13–18) had increased technology and social media use since the beginning of social distancing. Moreover, even after controlling for demographic factors, structural equation models showed that parents and children with higher levels of anxiety (as reported by parents) were more likely to increase their technology use and use social media and phones to connect.
Zhaojun Teng et al., 2020, China[37] A longitudinal study	n=1,778, children and adolescents (875 children, 903 adolescents)	videogame use, Internet Gaming	Depression-anxiety	The Internet Gaming Disorder Scale-Short Form (IGDS9-, impacts caused by the COVID-19 pandemic on different life domains (i.e., study activities, sleep quality, lifestyle habits [e.g., eating habits, physical exercise, and entertainment], social activities, and family relationships), The Chinese version of the Depression Scale (CES-D) and anxiety	The results indicated that both videogame use and Internet Gaming Disorder increased significantly for adolescents. The cross-lagged panel model results suggested that depressive and anxiety symptoms positively predicted Internet Gaming Disorder and video game use (especially for boys), but not inversely.
Pooja S Tandon et al., 2020, USA[38] A cross-sectional study	children aged 6 to 10 years and adolescents 11 to 17 years, n=547	Screen time	Depression-anxiety	the Strengths and Difficulties Questionnaire (SDQ), and other questions related to mental health problems	Children reported a mean (SD) of 3.9 (2.2) d/wks. with at least 60 minutes of physical activity and 4.4 (2.5) h/d of recreational screen time. COVID-19 stressors were significantly associated with higher total difficulties for both younger and older groups. More screen time was correlated with higher total difficulties among younger and older children. There were no significant differences by sex.