INTRODUCTION
============

Children today are exposed to various and ubiquitous screen media devices.[@B1] There is no exception on this trend among young children, and the age of initial exposure to devices is becoming younger; at present, exposure begins at early infancy.[@B2] In Korea, 38% of infants aged less than 11 months had been exposed to screen media and the average time of their screen exposure is about 2.4 hours per day.[@B3] There is a considerable amount of discussion on the consequences of screen exposure on school-aged children and adolescents. Excessive screen use has been associated with aggressive behavior,[@B4] social and peer problems.[@B5] However, there are comparatively few studies on preschool-aged children, because the widespread exposure to screen media devices is relatively recent; assessing the use of screen by young children is difficult.[@B6] In addition, there is growing evidence that young children interact with screen differently than older children.[@B7] Preschool-aged children who are not yet in their teens are the first generation to have been influenced by the omnipresence of media devices since birth. Moreover, the limitations of physical and cognitive functions of young children affect screen usage pattern.[@B8]

Nevertheless, certain studies have addressed the effect of screen exposure on preschool-aged children. The excessive screen media use of infants and toddlers has been found to possibly lead to behavioral problems,[@B3] cognitive impairment and poor family functioning in the long term.[@B9] Livingstone[@B10] pointed out that the use of digital screen devices by young children, who lack the appropriate technical, critical, and social skills, poses a greater risk. Considering these adverse effects, the American Academy of Pediatrics (AAP) recommends that the screen time of 2- to 5-year-old children must be limited to an hour per day.[@B11] Therefore, it is important to understand what factors affect young children\'s television viewing habit. A perspective focused on preschool-aged children is needed for early and adequate intervention. Previous studies have also indicated the necessity for longitudinal or age group-based research.[@B8][@B12] Young children\'s screen use is influenced by various factors; it is more directly dependent on family environment, such as parental guidance, than school-aged children.[@B13]

In keeping with this demand, an observational prospective cohort study has begun for a longitudinal investigation of the use of screen media devices for children in Korea, which is among the leading countries of media accessibility. As part of the cohort, this study is conducted to explore the exposure status and related factors of the use of screen media devices among 2- to 5-year-old children.

It is known that maternal depression has diverse effects on child-parental relationship, attachment, family functioning, and poor child outcomes.[@B14][@B15] For example, children of depressed mothers are more likely to have greater social impairment[@B16] and depressive symptoms.[@B17] Because these changes that children experience can affect their media use,[@B12] it is reasonable to expect that maternal depression may influence children\'s screen time. However, relatively little attention has been given to the association between maternal depression and screen time in young children.[@B18] In line with this, our study hypothesized that young children with depressed mothers would be more likely to overuse screen media devices than those with non-depressed mothers. As this study was specifically aimed at 2- to 5-year-old children, it could contribute to designing an early intervention and verify its future effectiveness.

METHODS
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Participants
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This study used data from the Internet-Cohort for Understanding of internet addiction Risk factors/Rescue in Early livelihood (I-CURE) study. The I-CURE study is the first long-term observational prospective cohort study investigating the causes and effects of internet-related diseases and disorders in children and adolescents in Korea. Based on the I-CURE cohort, studies have been conducted on children\'s smartphone and Internet game addiction.[@B19][@B20] A population-based sample of 400 children aged 2 to 5 years from three cities (Suwon, Goyang, and Seongnam) in Gyeonggi-do, Korea was recruited and consented to participate. All parents gave written informed consent and participated voluntarily. Data were collected between December 1, 2015 through June 30, 2016. Subsequently, the parents of 380 children (95% of those consents) provided sufficient data to be included in our study.

Depression measure
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Maternal depression was measured by the Korean version of the Beck Depression Inventory II (K-BDI-II), a 21-item self-report depression questionnaire. In this study, women with high BDI scores (≥ 22) were regarded as depressed mothers, considering previous study on the general population[@B21] and excluding false positives that have little effect on the actual behavior change.

Media use measure
-----------------

Parents were asked to report whether they owned the following six types of media devices: smartphone, television, computers (including laptops), tablet computers, video gaming consoles (e.g., Microsoft Xbox, Sony PlayStation), and portable gaming devices (e.g., Nintendo DS, Sony PlayStation portable). Subsequently, the average amount of screen time that children spent on each type of media during the past month was obtained. Using the screen for more than 1 hour per day was classified as screen overuse. This cut-off value was in accordance with the current AAP recommendations for 2- to 5-year-old children.[@B11]

Covariates
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Parents reported their child\'s gender and birthdate, from which the child\'s age was calculated. Familial structure and socioeconomic level was assessed by parents\' report including child\'s main caregiver, parental education and employment status, and monthly household income.

Statistical analysis
--------------------

First, to determine the sociodemographic factors that related with a high K-BDI-II score, we compared the frequency of the K-BDI-II positive rate between sociodemographic subgroups using χ^2^ test, applying Fisher\'s exact test if expected cell values were below five. Second, using screen overuse for each device as the main outcome, we performed multivariable logistic regression analysis with independent variables including sociodemographic variables and depression. We used odds ratios (ORs) and 95% confidence intervals (CIs) for screen time and covariates. All statistical analyses were conducted using SPSS version 24 (IBM Corp., Armonk, NY, USA).

Ethics statement
----------------

The study was approved by the Institutional Review Board at the Ajou University School of Medicine (AJIRB-SBR-SUR-14-378). Informed consent was obtained from all participants when they were enrolled.

RESULTS
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Participants\' demographics and screen use characteristics
----------------------------------------------------------

[Table 1](#T1){ref-type="table"} presents the demographic data and screen use status of 380 participants. Nearly all the children (94.2%) were cared for mainly by their parents. Most parents obtained college education. Half of the respondents had a monthly household income of above KRW 4,000,000, which is close to the median household income of KRW 4,222,533 in Korea in the same year (2015).[@B22] Almost all households owned televisions (94.7%), smartphones (95.8%), and computers (90.3%). In contrast, about half of the households owned tablets (48.2%), and only a few of them had video game consoles (14.7%) and handheld game consoles (10.0%). Slightly less than half of the enrolled children overused (i.e., more than one hour a day) televisions (48.4%). Only a few of the children overused smartphones (10.0%), tablets (6.3%), computers (3.9%), and video game console (0.5%). None of the children overused handheld game consoles.

###### Characteristics of participants

![](jkms-33-e219-i001)

  Characteristics                 No. (%)                 
  ------------------------------- ----------------------- ------------
  Age, yr                                                 
                                  2                       58 (15.3)
                                  3                       167 (43.9)
                                  4                       116 (30.5)
                                  5                       39 (10.3)
  Sex                                                     
                                  Male                    198 (52.1)
                                  Female                  182 (47.9)
  Main caregiver                                          
                                  Parents                 358 (94.2)
                                  Grandparents            19 (5.8)
  Paternal education                                      
                                  High school or below    41 (10.8)
                                  College or above        339 (89.2)
  Maternal education                                      
                                  High school or below    41 (10.8)
                                  College or above        337 (88.7)
  Paternal employment status                              
                                  Unemployed              5 (1.3)
                                  Employed                375 (98.7)
  Maternal employment status                              
                                  Unemployed              244 (64.2)
                                  Employed                136 (35.8)
  Monthly household income, KRW                           
                                  \< 4,000,000            190 (50.0)
                                  ≥ 4,000,000             190 (50.0)
  Ownership of media devices                              
                                  Television              360 (94.7)
                                  Smartphone              364 (95.8)
                                  Tablet                  183 (48.2)
                                  Computer                343 (90.3)
                                  Video game console      56 (14.7)
                                  Handheld game console   38 (10.0)
  Screen overuse (≥ 1 hr/day)                             
                                  Television              184 (48.4)
                                  Smartphone              38 (10.0)
                                  Tablet                  24 (6.3)
                                  Computer                15 (3.9)
                                  Video game console      2 (0.5)
                                  Handheld game console   0 (0.0)

Comparison between depressed and non-depressed mother groups
------------------------------------------------------------

Fifty-six (14.7%) mothers of participants scored positively on the K-BDI-II. The children\'s age, sex, main caregiver, parental employment status, and monthly household income between the two groups showed no significant difference. Depressed mothers and their spouses tended not to receive higher education than their counterparts. Also, depressed mothers tended to have monthly household income of less than KRW 4,000,000 than non-depressed mothers ([Table 2](#T2){ref-type="table"}).

###### Comparison between depressed mother group and non-depressed mother group

![](jkms-33-e219-i002)

  Characteristics                 Non-depressed mother (n = 324)   Depressed mother (n = 56)   χ^2^        *P* value
  ------------------------------- -------------------------------- --------------------------- ----------- -----------
  Age, yr                                                                                      2.306       0.511
                                  2                                49 (15.1)                   9 (16.1)    
                                  3                                141 (43.5)                  26 (46.4)   
                                  4                                103 (31.8)                  13 (23.2)   
                                  5                                31 (9.6)                    8 (14.3)    
  Sex                                                                                          0.003       0.959
                                  Male                             169 (52.2)                  29 (51.8)   
                                  Female                           155 (47.8)                  27 (48.2)   
  Main caregiver                                                                               0.592       0.755
                                  Parents                          304 (93.8)                  54 (96.4)   
                                  Grandparents                     20 (6.2)                    2 (3.6)     
  Paternal education                                                                           13.779      \< 0.001
                                  High school or below             27 (8.3)                    14 (25.0)   
                                  College or above                 297 (91.7)                  42 (75.0)   
  Maternal education                                                                           4.538       0.033
                                  High school or below             32 (9.9)                    11 (19.6)   
                                  College or above                 292 (90.1)                  45 (80.4)   
  Paternal employment status                                                                   0.112       0.551
                                  Unemployed                       4 (1.2)                     1 (1.8)     
                                  Employed                         320 (98.8)                  55 (98.2)   
  Maternal employment status                                                                   2.317       0.128
                                  Unemployed                       203 (62.7)                  41 (73.2)   
                                  Employed                         121 (37.3)                  15 (26.8)   
  Monthly household income, KRW                                                                5.362       0.029
                                  \< 4,000,000                     154 (47.5)                  36 (64.3)   
                                  ≥ 4,000,000                      170 (52.5)                  20 (35.7)   

Association between maternal depression and children\'s screen overuse
----------------------------------------------------------------------

[Table 3](#T3){ref-type="table"} presents the association between children\'s screen overuse and variables, such as maternal depression or sociodemographic factors on logistic regression. The screen overuse of video and handheld game consoles was not included in the analysis because the number of participants in the video game console (2) and handheld game console overuse (0) group was insignificant ([Table 1](#T1){ref-type="table"}). After adjusting for other variables, positive maternal K-BDI-II was a significant risk factor that almost doubles the risk of children\'s television overuse (adjusted OR, 1.954; 95% CI, 1.050--3.635). However, such finding was not observed in smartphones, tablets, and computers. A monthly household income of above KRW 4,000,000 was associated significantly and negatively with children\'s tablet overuse (adjusted OR, 0.257; 95% CI, 0.083--0.800).

###### Association between demographic and depression variable and children\'s screen overuse

![](jkms-33-e219-i003)

  Characteristics                 Television             Smartphone   Tablet                 Computer                                                                                                                     
  ------------------------------- ---------------------- ------------ ---------------------- ---------- -------- ---------------------- ------- -------- ----------------------- ------- -------- ----------------------- -------
  Depression (K-BDI-II)                                                                                                                                                                                                   
                                  0--21                  Ref                                                                                                                                                              
                                  ≥ 22                   0.670        1.954 (1.050--3.635)   0.034      0.452    1.572 (0.661--3.739)   0.306   −0.644   0.525 (0.131--2.107)    0.363   0.916    2.499 (0.699--8.933)    0.159
  Age, yr                                                                                                                                                                                                                 
                                  2                      Ref                                                                                                                                                              
                                  3                      −0.386       0.680 (0.364--1.269)   0.226      0.600    1.821 (0.679--4.886)   0.234   −0.804   0.447 (0.127--1.576)    0.211   0.122    1.130 (0.219--5.831)    0.884
                                  4                      −0.446       0.640 (0.330--1.239)   0.186      −0.591   0.554 (0.163--1.880)   0.343   0.039    1.040 (0.295--3.666)    0.951   −0.938   0.391 (0.051--2.987)    0.366
                                  5                      −0.761       0.467 (0.198--1.103)   0.082      −0.837   0.433 (0.078--2.413)   0.340   −0.660   0.517 (0.080--3.319)    0.487   0.664    1.942 (0.287--13.159)   0.496
  Sex                                                                                                                                                                                                                     
                                  Male                   Ref                                                                                                                                                              
                                  Female                 0.162        1.176 (0.769--1.800)   0.455      −0.594   0.552 (0.265--1.152)   0.113   −0.568   0.567 (0.221--1.451)    0.236   −0.168   0.845 (0.271--2.636)    0.730
  Main caregiver                                                                                                                                                                                                          
                                  Parents                Ref                                                                                                                                                              
                                  Grandparents           0.097        1.102 (0.431--2.820)   0.839      0.188    1.206 (0.227--6.417)   0.826   0.285    1.330 (0.132--13.393)   0.809   0.419    1.521 (0.141--16.406)   0.772
  Paternal education                                                                                                                                                                                                      
                                  High school or below   Ref                                                                                                                                                              
                                  College or above       −0.018       0.982 (0.457--2.110)   0.963      −0.517   0.596 (0.219--1.622)   0.311   −0.486   0.615 (0.166--2.276)    0.466   1.022    2.779 (0.294--26.229)   0.372
  Maternal education                                                                                                                                                                                                      
                                  High school or below   Ref                                                                                                                                                              
                                  College or above       −0.618       0.539 (0.255--1.140)   0.106      −0.853   0.426 (0.162--1.119)   0.083   −0.883   0.413 (0.131--1.309)    0.133   −0.316   0.729 (0.131--4.062)    0.718
  Maternal employment status                                                                                                                                                                                              
                                  Unemployed             Ref                                                                                                                                                              
                                  Employed               −0.067       0.936 (0.580--1.509)   0.785      0.094    1.099 (0.485--2.492)   0.821   0.048    1.049 (0.380--2.895)    0.926   −0.723   0.485 (0.126--1.863)    0.292
  Monthly household income, KRW                                                                                                                                                                                           
                                  \< 4,000,000           Ref                                                                                                                                                              
                                  ≥ 4,000,000            −0.018       0.990 (0.629--1.558)   0.964      −0.503   0.604 (0.269--1.356)   0.222   −1.357   0.257 (0.083--0.800)    0.019   0.175    1.191 (0.375--3.776)    0.767

Adjusted with age, sex, main caregiver, maternal education, paternal education, maternal employment status, and monthly household income.

OR = odds ratio, CI = confidence interval, K-BDI = Korean Version of the Beck Depression Inventory, Ref = reference.

DISCUSSION
==========

This study was conducted to determine the association between maternal depression and children\'s screen overuse. As expected, children with depressed mothers were more likely to overuse television. This finding is consistent with the previous studies on preschool-aged children\'s television use.[@B18][@B23] Maternal depression is associated with negative parental behavior and weakens child behavior management.[@B14] It is also clear that such change of parental behavior has a significant impact on children\'s media use.[@B12] There are several suggestions on how this effect is mediated. Although this study did not directly measure parental television use, parents\' media use is an important determinant of their children\'s.[@B12] Parental time spent using screen devices is positively associated with preschool-aged children\'s screen time.[@B24] Meanwhile, there are consistent reports indicating that depressed adults tend to spend more time watching television.[@B25] Depressed mothers may use television as a coping mechanism, relieving their anhedonia and helping them avoid unpleasant emotions and stimuli.[@B26] Thus, children of depressed mothers watch more television because their mothers also do so. Moreover, depressed mothers tend to think that their children feel more pleasure from television than they can provide.[@B27] Therefore, it is reasonable to assume that depressed mothers find it hard to reduce their children\'s television viewing time, because they use television as a babysitter to replace their depressed self.

Maternal depression affects qualitative aspects of parenting and family functioning.[@B28] Maternal depressive symptoms, such as sadness, loss of energy, and irritability, can affect adversely the effective control of children\'s behavior and maintenance of positive parent-child attachment.[@B29] Thus, depressed mothers showed a more negative or coercive parenting behavior and less positive parenting behavior or engagement.[@B14] Predictably, maternal parenting behavior is related to the amount of time children spend watching television. Low parental engagement is associated with screen overuse in preschool-aged children.[@B7] Mothers\' authoritarian parenting styles are positively associated with their children\'s television watching time.[@B30] Authoritarian parents, one of the four classification of parenting styles identified by Baumrind,[@B31] tend to have less verbal give and take with their children, emphasize obedience without question, and more likely to be angry or critical toward their children. These characteristics are similar to those seen in the parenting patterns of depressed parents.[@B32] In particular, parenting attitudes that are similar to depressive parenting behaviors, such as less democratic parenting or weak parental attachment, are associated with screen overuse.[@B33] Hence, it is plausible that the parenting factors of depressed mothers can cause their children\'s screen overuse.

Contrary to expectations, the relationship between maternal depression and children\'s screen overuse was not present on other devices, except for television. This is a questionable result because it can be plausibly expected that changes in parental behavior, attachment, and family environment due to maternal depression will have similar effect on other screen devices, aside from television. This discrepancy might be understood in the context of the child\'s development. As the use of a certain screen device requires an adequate level of physical and cognitive functioning for the device, age-based developmental level of the child affects media usage pattern.[@B8][@B12]

Screen devices, such as computers and gaming consoles, require "active" manipulation. Users need to be attentive on the screen and perceive and respond appropriately to the stimuli appearing on the screen. The children must also have enough strength, agility, and motor coordination to handle the input devices, such as mouse devices and keyboards. In other words, children need adequate levels of cognitive and motor development to handle the devices. In the case of smartphones and tablets, motor function is relatively less important; however, the cognitive level of 3.5-year-old children is necessary to understand symbolic and icon-based information display.[@B34] Meanwhile, television is relatively a "passive" medium and requires less development of motor and cognitive functions. Young children may be exposed to "background" television, where they pay less overt attention to the content of television, unlike in "foreground" exposure.[@B35]

Because this study was derived from the baseline data collection of the I-CURE cohort, participants in the study were confined to children aged 2 to 5 years. Children in this age group can be too young to use a medium that requires "active" manipulation. According to the common sense media research study, 70% of screen use by children under 8 years old was through watching television or DVD, whereas their use of an "active" medium (e.g., computers, gaming consoles, and mobile devices) was a relatively small portion.[@B36] In this study, the overuse rate of other devices except television was less than 10%, suggesting that the association with maternal depression may not be evident because the overuse of "active" devices was exceptional in this age group covered by the study.

Several limitations of this study must be remarked. Children\'s screen use was measured by parental reporting, which is known to produce little overestimation compared with daily log or direct observation.[@B37] In addition, K-BDI-II was designed as a screening tool rather than a diagnostic tool; thus, it may not reflect accurately the depressive symptoms of the mother. Current screen overuse can cause various long-term effects as well as predict future screen overuse. Children\'s electronic media use has a dose-dependent association with an increase in emotional problems and poorer family functioning two years later,[@B38] and television exposure prior to age 3 is associated with attentional problems at age 7.[@B39] Moreover, greater television exposure in early childhood is linked to greater television viewing at school age.[@B40] However, this study is a cross-sectional study, which does not allow inferring any longitudinal causal relations. Subsequent studies based on this cohort are expected to elucidate the trajectory and long-term effects.

This study considers only the effects of maternal depression on the quantitative aspects of screen use. However, maternal depression also affects the qualitative features of children\'s media use. For example, depressed mothers were less likely to interact with their children during television use or seek information on proper media use.[@B27] Qualitative factors of screen use, such as children\'s attention or interaction with parents during television use, can also mediate the effect of children\'s media use.[@B35]

This study investigated the relationship between maternal depression and screen overuse in preschool-aged children. Maternal depression (K-BDI-II ≥ 22) is associated with television overuse in children aged 2 to 5 years but not with smartphones, tablets, and computers. This association may be derived from changes in parent-child relationship, parenting behavior, and family environment due to maternal depression. The reason this association does not appear in smartphones, tablets, and computers seems to be that the participants have not yet reached the level of cognitive and motor development sufficient to use devices that require active manipulation. This study not only provides a basis for future follow-up studies using the I-CURE cohort but also emphasizes that early intervention for maternal depression in young children is important in preventing screen overuse.

**Funding:** This research was supported by a grant from the Korean Mental Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HM14C2603).

**Disclosure:** The authors have no potential conflicts of interest to disclose.

**Author Contributions:** Conceptualization: Park S, Shin YM. Data curation: Chang HY, Yoo HJ, Kim S. Formal analysis: Kim S. Methodology: Park S, Chang HY, Park EJ, Jo W. Writing - original draft: Park S, Shin YM. Writing - review & editing: Chang HY, Jo W, Shin YM.
