Introduction

Mental health problems (which can include depression, anxiety and substance use disorders) are a leading cause of disability and mortality [1] and thus are a particular global public health concern. The global cost of mental health problems in 2010 was estimated to exceed US$ 2.5 trillion, with the cost predicted to rise to US$ 6.0 trillion by 2030 [2]. Current estimates suggest that 45% of adults in Australia [3] and 32% of adults in the US [4] will suffer from a mental health disorder in their lifetime, with anxiety disorders identified as the most common mental health issue amongst Australian [3] and US adults [4]. The cost of this illness impacts significantly on the public health system, families, as well as workplaces, with anxiety being linked to increased absenteeism and decreased productivity in the workplace [5]. Women are a high-risk group for developing anxiety, with women aged 25–34 years shown to be almost twice as likely to experience an anxiety disorder compared with men of the same age [3]. Further, the risk of anxiety has been shown to peak between the ages of 25–44 [3], which reflects the key childbearing years for women. Considering anxiety affects one’s quality of life and psychosocial functioning [6], with maternal anxiety also being shown to be a key predictor of child anxiety [7], it is important that strategies are identified to reduce the risk of anxiety in mothers.

Much evidence has suggested that physical activity (in particular that of which is undertaken during leisure-time) is beneficial for reducing anxiety symptoms [8,9]. However, mothers with young children (e.g. women with children aged under 5 years) often face great barriers to engaging in physical activity compared to the general population, and hence are more likely to be physically inactive [10]. Such barriers include lack of time and social support, and prioritising family commitments over their own personal well-being [11]. Thus, attempting to increase physical activity in mothers with young children may not be an effective means of reducing risk of anxiety. Additional behavioural strategies to reduce the risk of anxiety may need to be explored, such as reducing sedentary behaviour.

Sedentary behaviour is distinct from physical inactivity, being defined as sitting or reclining behaviours undertaken at or just above the resting metabolic rate [12]. Adults spend more than 50% of their waking time engaged in sedentary behaviour [13]. Although prevalence data for mothers specifically is limited, evidence shows that those aged 25–34 years (which is generally key childrearing age) spend the greatest amount of time in sedentary behaviour compared to any other age group. Television viewing and computer/internet use have been shown to be the most commonly reported sedentary behaviours amongst this age group [14]. Since parental screen time has been positively associated with preschool children’s screen time [15], targeting reductions in screen time amongst mothers may have positive impacts across two generations (i.e. mother and child).

A growing body of evidence shows that sedentary behaviour is linked to adverse health outcomes, including all-cause and cardiovascular disease mortality, independent of physical activity [16,17]. In terms of behaviour change, research has suggested that reducing sedentary behaviour may be viewed by adults as “easier” than increasing physical activity by adults, given that “lack of time” (the key barrier to being active) is not generally a barrier to reducing one’s sedentary behaviour [18], and that reducing sedentary behaviour is less physically demanding than increasing physical activity. Therefore, targeting reductions in sedentary behaviour may be more appealing and/or feasible for time-poor mothers with young children, compared to targeting increases in physical activity.

Sedentary behaviour has been recently positively linked to increased anxiety symptoms in the general population [19]. A systematic review of the association between sedentary behaviour and anxiety risk concluded that although there was a small amount of evidence to suggest a positive association between sitting time and anxiety risk, there was limited and inconsistent evidence for the relationship of other sedentary behaviours including screen time, television viewing time and computer use with anxiety risk [19]. For example, a previous study showed that television viewing and total screen-time were positively associated with anxiety symptoms, however, computer use was not [20]. In contrast, another study showed that computer use was positively associated with anxiety symptoms, however, TV viewing was not [21]. Given that individual sedentary behaviours (e.g. TV viewing, computer/device use) may have varying associations with anxiety symptoms due to the differences in contexts and purposes for engagement, it is essential to examine the link between individual sedentary behaviours, in particular screen-based entertainment such as television viewing and computer/device use, and anxiety risk.

No previous studies have investigated the link between more modern screen-based sedentary behaviours (i.e. tablet/device use) and anxiety risk, nor have any previous studies focussed on mothers with young children (a high-risk group for anxiety). Therefore, the aim of this study was to investigate the associations between screen-based sedentary behaviour (including TV/DVD viewing, and computer/e-games/device use) and anxiety symptoms, independent of physical activity, amongst mothers with young children.

Although research is currently limited and inconsistent regarding the link between screen-based sedentary behaviour (e.g. TV viewing, computer use) and anxiety risk, drawing on a larger and more consistent body of evidence indicating a positive association between screen-based sedentary behaviour and other mental health outcomes (particularly that of depression) [22], it was hypothesised that engagement in all screen-based sedentary behaviours would be associated with heightened anxiety symptoms, independent of physical activity, in the current study.

Materials and Methods

This study utilised cross-sectional survey data collected in 2013 and 2014 from 575 mothers (with children aged 2–5 years) as a part of the “Mums, Dads and Kids Study”.

Results

Table 1 presents the socio-demographic characteristics among participants. The mean age of participants was 37.18 (SD = 4.62) years. Most women (95%) were married or in a de facto relationship, and nearly three quarters (74%) of the sample had completed a tertiary degree. Overall, 29.4% of women were experiencing anxiety symptoms.

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Table 1. Socio-demographic characteristics of women (n = 528).

https://doi.org/10.1371/journal.pone.0155696.t001

Associations between screen-based sedentary behaviours and anxiety symptoms are presented in Table 2. In crude and adjusted models, computer/device use was positively associated with a higher likelihood of anxiety symptoms (B = 0.265 and 0.212 respectively). That is, in the adjusted model, every hour increase in computer/device use was associated with a 0.21 point increase in anxiety symptom score. A positive relationship was also shown for the association between overall screen time and anxiety symptoms in both crude and adjusted models (B = 0.131; B = 0.109 respectively). However, TV viewing was not associated with anxiety symptoms in either model.

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Table 2. Linear regression analyses examining associations between sedentary behaviours and anxiety symptoms.

https://doi.org/10.1371/journal.pone.0155696.t002

Interaction analyses showed no interactions between screen time, MVPA and anxiety symptoms in either the unadjusted or the adjusted models.

Discussion

The current study builds on the very small existing body of research investigating the relationship between sedentary behaviour and anxiety symptoms. To date, no other studies have investigated the link between modern screen-based sedentary behaviours (i.e. tablet/device use) and anxiety symptoms, nor have studies focussed on mothers with young children. Our findings showed that certain screen-based sedentary behaviours (i.e. computer/hand held device use and overall screen time) were positively linked to anxiety symptoms in mothers with young children, independent of physical activity.

Specifically, this study found that higher levels of computer and/or hand held device use were associated with heightened anxiety symptoms in mothers with young children. This is consistent with findings from one other cross-sectional study that suggested that computer use was positively associated with anxiety symptoms in Australian adults [21]. One potential explanation for this relationship is that women often use computers/devices to utilise social media sites such as Facebook, Instagram and Twitter, which may have negative emotional and mental health effects. For example, one study has shown that nearly 50% of female Facebook users felt “addicted” to Facebook, 77% reported being online longer than they intend to be, and one quarter lost sleep because of Facebook [27]. This suggests that engagement in social media may lead to addictive tendencies and thus heightened symptoms of anxiety. However, since the current study did not measure social media usage specifically, the purpose of participants’ computer/device use is unknown and thus not necessarily spent on such sites, and hence other explanations are equally plausible. An alternate explanation for the positive relationship between computer/devise use and anxiety symptoms in mothers with young children is that the time spent using the computer/devise may remove them from other responsibilities such as household chores, engaging with their children, etc., which may subsequently lead to feelings of stress and anxiety. However, only two previous studies have investigated the association between computer use and anxiety risk [20,21], both of which did not assess modern screen-based sedentary behaviour (e.g. devise/tablet/smartphone use which was assessed in the current study) and thus a recent review of the literature concluded that there was insufficient data (i.e. only two previous studies with inconsistent findings) to show evidence of a relationship between computer use and anxiety risk [19]. Therefore, further research is needed to confirm the findings of the current study.

In the current study, overall screen time was also found to be linked to heightened anxiety symptoms. These findings are consistent with two previous cross-sectional studies which suggested that higher levels of screen time (i.e. TV and computer use collectively) were associated with increased anxiety symptoms in both adolescents [28] and adults [20]. In contrast to these findings, one previous study has shown an inverse association between screen time (i.e. combined TV, computer and electronic games use) and risk of anxiety, suggesting that greater engagement in screen-based entertainment was linked to lower levels of anxiety symptoms [29]. However, that study included a sample of 5-year old children and therefore the conflicting findings may be explained by the different target groups included in studies. It may be that screen time is more likely to impact on adult’s anxiety risk compared to children’s. Nevertheless, since only four observational studies (three cross-sectional and one longitudinal) have examined the link between screen time and anxiety symptoms [20,28,29,30], with inconsistent results (and none of which have focussed specifically on mothers), further longitudinal and intervention studies are needed to confirm findings from this study.

Parental anxiety has been linked to poor parenting practices (such as over maternal criticism [31]), lower quality child-parent interactions (e.g. anxious mothers are often less engaged and more withdrawn from their children [32]), poorer child behavioural and emotional outcomes (e.g. hyperactivity, conduct and emotional problems) [33] and a significantly increased risk of anxiety developing in their children [34]. Such outcomes (e.g. poor parenting practices, lower quality child-parent interactions, child behavioural/emotional problems) could also be hypothesised to be linked to parental screen-time, although the current body of literature is scarce. Thus, if findings of the current study are confirmed, implementing strategies such as reducing mother’s screen-based sedentary behaviour may have broad implications for families.

This study found no association between TV viewing and anxiety symptoms in mothers with young children. Only three previous cross-sectional studies have investigated the association between TV viewing and anxiety risk [20,21,35]. Our findings are consistent with one of those studies which was conducted in Australian adults [21]. Although two previous studies have found a positive association between TV viewing and anxiety symptoms [20,35], on balance there appears to still be insufficient evidence for the relationship between TV viewing and anxiety risk [19]. One such explanation for the lack of association between TV viewing and anxiety symptoms in the current study is that mothers may use TV viewing as a form of relaxation. This hypothesis is supported by one previous study amongst disadvantaged women with depressive symptoms, whereby TV viewing was suggested to be a tool women used to “switch off” and divert negative thoughts [36].

Finally, the current study showed that there was no interaction between screen time and physical activity, suggesting that sedentary behaviour was linked to risk of anxiety symptoms, independent of physical activity. Although no other studies have examined the potential interaction between sedentary behaviour, physical activity and anxiety risk specifically, one previous study has shown that physical activity was inversely linked to risk of a mental disorder (depression and anxiety combined), independent of sedentary behaviour [30]. Collectively, these results indicate that physical activity and sedentary behaviour may both be linked to risk of mental illness/anxiety symptoms; however, these relationships are likely to be independent of one another.

Limitations of this study should be acknowledged. Firstly, the study design was cross-sectional which does not allow for causality to be determined. For example, it is not known whether screen time predicts anxiety symptoms or whether anxiety symptoms predict screen time. Secondly, the sample was highly educated, with 75% of women having completed a University degree. Considering less educated adults are more likely to engage in leisure-time sedentary behaviours and be at risk of anxiety [37], further studies including a more representative sample of the population are needed. Nevertheless, analyses did control for education in this study to reduce the potential of such confounding relationships. Finally, only two leisure-time sedentary behaviours were assessed and therefore it is still unknown as to whether work or transport-related sedentary behaviours are linked to anxiety symptoms.

A key strength of this study is that it examined modern screen-based sedentary behaviours including device use (e.g. tablets and smartphones), which no other studies examining the association between sedentary behaviour and anxiety have done. Furthermore, this study controlled for a number of confounding factors including MVPA, which enabled the association between sedentary behaviour and anxiety symptoms, independent of physical activity, to be demonstrated.