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Keywords:

  • anxiety;
  • bedroom;
  • depression;
  • insomnia;
  • media use;
  • sleep habits

Summary

  1. Top of page
  2. Summary
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusions
  8. References

This postal questionnaire study investigated the use of media in the bedroom and its relationships with sleep habits and symptoms of insomnia. The sample comprised 2500 individuals aged 16–40 years drawn randomly from the Norwegian national register. A total of 816 (34.0%) completed and returned the questionnaire. Respondents were asked how often they used computers, television sets, DVD players, game consoles and mobile telephones and listened to music/radio in their bedrooms. They also reported sleep habits on weekdays and at weekends/days off and symptoms of insomnia. After controlling for gender, age, anxiety and depression, the respondents who used a computer in the bedroom ‘often’ compared to ‘rarely’ rose later on weekdays and at weekends/days off, turned off the lights to go to sleep later at weekends/days off, slept more hours at weekends/days off and had a greater discrepancy between turning off the lights to go to sleep on weekdays and at weekends/days off. Respondents who used a mobile telephone in their bedrooms at night ‘often’ compared to ‘rarely’ turned off the lights to go to sleep later on weekdays and at weekends/days off, and rose later at weekends/days off. No such differences were found with the use of the other media. There were also no significant differences in symptoms of insomnia. This study indicates that the use of computers and mobile telephones in the bedroom are related to poor sleep habits, but that media use in the bedroom seems to be unrelated to symptoms of insomnia.


Introduction

  1. Top of page
  2. Summary
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusions
  8. References

With the increase in use of various electronic media, such as television, computers, video games, mobile telephones and audio devices, it is becoming increasingly important to investigate how media use is affecting individuals’ lifestyles. One important avenue for research on this topic is to investigate whether media use is related to poor sleep habits and symptoms of insomnia.

Most of the sparse research on the relationship between media use and sleep has focused on the effect of media use on sleep among children and adolescents. It has been found that children with a television set in their bedrooms go to bed later on both weekdays and at weekends, and spend fewer hours in bed on weekdays, compared to children who do not have a television set in their bedrooms. Also, children with a gaming console in their bedrooms go to bed later at weekends and spend fewer hours in bed on weekdays, compared to children without a gaming console in their bedrooms (Van Den Bulck, 2004). The same tendency has been found with the use of mobile telephones. Research has shown that the more children used their mobile telephones after lights out, the more likely they were to feel tired at 1-year follow-up (Van Den Bulck, 2007). Among adolescents, the amount of time spent multi-tasking in late evenings, including media use (television, mobile telephone, online computer use, computer games, listening to music) has been found to be related negatively to the number of hours of sleep obtained on school nights (Calamaro et al., 2009).

Very few studies have investigated the association between media use and sleep in adults. One study found that the more hours adults spent watching television and using the internet before sleep, the more likely they were to report insufficient sleep (Suganuma et al., 2007). However, a different study found that good sleepers and poor sleepers did not differ on the average number of days per week they watched television in bed (Gellis and Lichstein, 2009). Because of such inconsistent findings, and because of the scarcity of studies investigating the relationship between media use and sleep among adults, more research is warranted.

In addition to having focused mainly on children and adolescents, studies in the field have also often neglected to control for variables which may be related to media use, sleep habits and symptoms of insomnia, such as gender, age, anxiety and depression. For example, research on adolescents has shown that girls generally talk more on the telephone and use online instant messaging more often than boys, while boys play video games more often than girls (Ohannessian, 2009). It is well documented that women have a greater risk of insomnia compared to men (Ford and Kamerow, 1989; Sivertsen et al., 2009; Zhang and Wing, 2006). The relationship between insomnia and depression and anxiety is also well established (Taylor et al., 2005). In several studies, age has been associated with sleep habits and insomnia. Adolescents and young adults seem to have a greater general preference for staying up late and to rise late (Roenneberg et al., 2004). The prevalence rate of insomnia increases with age (Sivertsen et al., 2009). Media use may also be more prevalent in younger compared to older adults (Suganuma et al., 2007). Based on these findings, gender, age, anxiety and depression should consequently be controlled for in studies of the relationship between media use and sleep, as they may be possible confounders.

In this study we investigated the relationship between media use and sleep habits and symptoms of insomnia in a randomized sample of Norwegians aged 16–40 years. We investigated whether use of computers, television, DVD players, video game consoles, mobile telephones and audio devices in the bedroom would be associated with the time at which respondents went to bed on weekdays and at weekends/days off, when they rose on weekdays and at weekends/days off, the number of hours of sleep they had on weekdays and at weekends/days off, the differences between getting up and going to sleep on weekdays versus at weekends/days off, as well as with symptoms of insomnia.

Methods

  1. Top of page
  2. Summary
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusions
  8. References

Participants

A representative sample comprising 2500 Norwegians between the ages of 16 (including 15-year-olds who turned 16 that year) and 40 years were selected randomly from the national register. Anonymous self-report questionnaires were distributed to the sample by postal mail. Respondents had the option of completing the questionnaire on paper and returning it in an enclosed prepaid envelope, or completing the questionnaire online. Due to failure to locate addresses, 101 questionnaires were returned by the postal service. A total of 816 questionnaires were completed and returned, yielding a response rate of 34.0%. The participants consisted of 56.1% women and 43.9% men. Mean age was 27.9 [standard deviation (SD) = 7.4] years. The study was approved by the Regional Committees for Medical and Health Research Ethics in western Norway.

Measures

Media use

Participants were asked to indicate how often they used a computer in their bedrooms, watched television in their bedrooms, used a DVD player in their bedrooms, used a game console in their bedrooms, used a mobile telephone in their bedrooms at night and listened to music/radio in bed. Participants responded on a scale which contained the following alternatives: ‘every day’, ‘4–6 days per week’, ‘2–3 days per week’, ‘1 day per week’, ‘1–3 days per month’, ‘more rarely than 1 day per month’ and ‘never’. Table 1 shows the percentages of use of all types of media.

Table 1.   Percentages for use of each media type in the bedroom for all respondents
FrequencyComputerTVDVDGamesMobileMusic
Never48.075.275.991.526.044.9
<1 day per month11.33.38.62.59.114.0
1–3 days per month5.93.25.71.76.07.1
1 day per week4.72.02.80.73.95.4
2–3 days per week5.54.22.60.95.27.5
4–6 days per week5.83.21.50.57.07.5
Every day18.79.03.02.242.713.5
Sleep habits

Participants indicated at what hour they switched off the lights and tried to go to sleep on weekdays, at what hour they usually got up on weekdays, how many hours of sleep they usually had per day on weekdays, at what hour they switched off the lights and tried to go to sleep at weekends/days off, at what hour they usually got up at weekends/days off, and how may hours of sleep they usually had per day at weekends/days off.

Bergen Insomnia Scale (BIS)

BIS (Pallesen et al., 2008) measures symptoms of insomnia using six items on which participants indicate how many days per week during the last month they experienced problems with different aspects of sleep. Internal consistency (Cronbach’s alpha) for the BIS scale in this study was 0.83. The total composite score ranged from 0 to 42.

Hospital Anxiety and Depression Scales (HADS)

HADS (Zigmond and Snaith, 1983) measures anxiety (seven items) and depression (seven items). On each item participants indicate which of four response alternatives (ranging from 0 to 3) they agree mostly with concerning statements about non-vegetative symptoms of anxiety and depression. Thus, each scale yields a score ranging from 0 to 21. Internal consistency (Cronbach’s alpha) in this study was 0.73 for the anxiety subscale and 0.77 for the depression subscale.

The participants were also asked to provide information about their gender and age.

Statistics

The data were analysed using Predictive Analytics SoftWare (PASW) Statistics release version 17.0 for Windows (SPSS Inc., 2009). Gender was coded 1 = men, and 2 = women. All media variables were dichotomized because they failed to show normal distributions. The first category was named ‘rarely’, and comprised the response alternatives ‘1 day per week’, ‘1–3 days per month’, ‘more rarely than 1 day per month’ and ‘never’. The second category was named ‘often’, and comprised the response alternatives ‘every day’, ‘4–6 days per week’ and ‘2–3 days per week’.

Pearson’s product–moment correlation coefficients were calculated for relationships between continuous variables, point-biserial correlations coefficients were calculated for relationships between dichotomous variables and continuous variables, and phi-coefficients were calculated for relationships between dichotomous variables.

Hierarchical multiple regression analyses were conducted in order to investigate how media use was associated with sleep habits and symptoms of insomnia. For each sleep variable, gender, age, depression and anxiety were entered into the first step of the regression analysis. In the second step, computer use, TV watching, DVD use, game-playing, mobile telephone use and listening to music were added.

Results

  1. Top of page
  2. Summary
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusions
  8. References

Background variables and media use

Descriptive statistics and intercorrelations between background and media use variables are presented in Table 2. Gender was correlated negatively with using a game console in the bedroom but positively with using a mobile telephone in the bedroom. Age was correlated negatively with all kinds of media use (computer, watching television, using a DVD player, using a game console, using a mobile telephone and listening to music) in the bedroom. Anxiety was correlated positively with using a computer, using a DVD player, using a mobile telephone and listening to music/radio in the bedroom. Finally, depression was correlated positively with using a DVD player in the bedroom.

Table 2.   Means, standard deviations (SD) and intercorrelations between background variables and media use
VariableMean (SD)123456789
  1. Gender was coded 1 = male, 2 = female.

  2. *P <0.05; **P <0.01.

GenderFemale n = 458, male n = 358        
Age27.86 (7.36)−0.06       
Anxiety5.04 (3.05)0.06−0.12**      
Depression2.96 (2.94)−0.08*0.030.58**     
Computer‘rarely’n = 568, ‘often’= 244−0.06−0.51**0.11**0.03    
TV‘rarely’n = 680, ‘often’n = 133−0.01−0.29**0.040.030.37**   
DVD‘rarely’n = 758, ‘often’n = 57−0.06−0.20**0.08**0.07*0.22**0.53**  
Games‘rarely’n = 782, ‘often’n = 29−0.11**−0.19**0.010.040.21**0.29**0.44** 
Mobile‘rarely’n = 366, ‘often’n = 4460.12**−0.23**0.060.000.19**0.15**0.12**0.04
Music‘rarely’n = 581, ‘often’n = 2320.03−0.37**0.10**0.000.43**0.22**0.18**0.19**0.20**

Background variables and sleep

Mean time for turning off the lights or to go to sleep was 23:20 hours (SD = 55.1 min) on weekdays, and 00:42 hours (SD = 81.1 min) at weekends/days off. The mean rise time was 07:03 hours (SD = 65.3 min) on weekdays and 09:38 hours (SD = 97.9 min) at weekends/days off. The respondents slept for an average of 07:06 hours (SD = 1.11 h) per night on weekdays, and 08:47 hours (SD = 1.47 h) per night at weekends/days off. The mean insomnia (BIS) score for the respondents was 11:02 hours (SD = 8.35).

The results of hierarchical multiple regression analyses are shown in Table 3. Women turned off the lights earlier on weekdays and at weekends/days off, and rose earlier at weekends/days off compared to men. Women also reported higher levels of insomnia symptoms than men. There was a negative association between age and the following variables: time for turning off the lights at weekends/days off, time rising from bed at weekends/days off, hours of sleep both on weekdays and at weekends/days off and the magnitude of the discrepancy between weekdays and weekends/days off concerning time for turning off the lights and rising.

Table 3.   Hierarchical multiple regression of background variables and media use predicting sleep habits and insomnia
 Lights off weekdaysRise time weekdaysLights off weekendsRise time weekendsHours of sleep weekdaysHours of sleep weekendsWeekday–weekend difference lights offWeekday–weekend difference rise time Symptoms of insomnia
βR2 changeβR2 changeβR2 changeβR2 changeβR2 changeβR2 changeβR2 changeβR2 changeβR2 change
  1. *< 0.05; **< 0.01; ***< 0.001.

Step 1
 Gender 1 = male, 2 = female−0.156***0.030***−0.0170.040***−0.144***0.108***−0.066*0.243***0.0520.070***−0.0190.084***−0.0520.128***−0.0540.155***0.102**0.277***
 Age−0.028−0.151***−0.299***−0.482***−0.201***−0.280***−0.360***−0.396***−0.020
 Anxiety0.109*0.112*0.0370.034−0.097*−0.012−0.0410.0440.305***
 Depression−0.087*0.005−0.0100.062−0.097*−0.0730.0510.0600.274***
Step 2
 Gender−0.174***0.032***−0.0180.019*−0.146***0.031***−0.064*0.032***0.0580.002−0.0130.010−0.0400.015*−0.0520.016**0.094**0.005
 Age0.034−0.080−0.195***−0.370***−0.187***−0.225***−0.279***−0.331***0.002
 Anxiety0.094*0.099*0.0210.025−0.094*−0.017−0.048−0.0440.299***
 Depression−0.0790.011−0.0060.059−0.099*−0.072−0.0490.0540.278***
 Computer, 1 = ‘rarely’, 2 = ‘often’0.0490.124**0.124**0.105**0.0330.094*0.115**0.0190.008
 TV, 1 = ‘rarely’, 2 = ‘often’−0.040−0.043−0.0100.0370.0220.0180.0230.070−0.007
 DVD, 1 = ‘rarely’, 2 = ‘often’0.0090.002−0.005−0.011−0.035−0.055−0.015−0.0120.007
 Games, 1 = ‘rarely’, 2 = ‘often’−0.038−0.029−0.0090.0330.0320.0130.0190.054−0.029
 Mobile, 1 = ‘rarely’, 2 = ‘often’0.156***0.0670.103**0.105**−0.0130.0050.0020.0600.052
 Music, 1 = ‘rarely’, 2 = ‘often’0.0560.0310.0660.054−0.0170.0290.0390.0330.036
 Modell R20.061***0.058***0.139***0.275***0.072***0.095***0.143***0.171***0.282***

Anxiety was associated positively with the time at which the respondents turned off the lights on weekdays, rise time on weekdays and symptoms of insomnia. Anxiety was associated negatively with hours of sleep on weekdays. Depression was associated negatively with sleep duration on weekdays, and associated positively with symptoms of insomnia.

Media use and sleep

On average, the respondents who used a computer in the bedroom ‘often’ compared to ‘rarely’ rose later on weekdays [07:09 hours, standard error (SE) = 7.0 min versus 06:51 hours (SE = 7.3 minutes)] and at weekends/days off (10:05 hours, SE = 9.8 min versus 09:41 hours, SE = 9.4 min), turned off the lights to go to sleep later at weekends/days off (00:56 hours, SE = 8.8 min versus 00:34 hours, SE = 8.5 min), slept longer at weekends/days off (08:38 hours, SE = 9.6 min versus 08:20 hours, SE = 9.3 min) and had a greater discrepancy between turning off the lights to go to sleep on weekdays and at weekends/days off (01:37 hours, SE = 6.9 min versus 01:21 hours, SE = 6.6 min). On average, the respondents who used a mobile telephone in the bedroom at night ‘often’ compared to ‘rarely’ turned off the lights to go to sleep later on weekdays (23:24 hours, 5.6 min) versus 23:07 hours, SE = 5.9 min) and at weekends/days off (00:53 hours, SE = 8.1 versus 00:36 hours, SE = 8.5) and rose later at weekends/days off (10:04 hours, SE = 9.0 min versus 09:43 hours, SE = 9.4 min). There was no difference between the ‘often’ and ‘rarely’ groups concerning TV use, DVD player use, game console use and listening to music/radio in bed in terms of sleep habits. Finally, there were no significant associations between the use of any of the media in the bedroom ‘often’ and ‘rarely’ and symptoms of insomnia.

Discussion

  1. Top of page
  2. Summary
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusions
  8. References

The results showed that men used game consoles in the bedroom significantly more often than did women. This finding is in line with previous research which has shown that men in general are more likely to play games compared to women (Lucas and Sherry, 2004). Hence, our finding concerning gender differences in bedroom behaviours in terms of game-playing is interpreted as a reflection of the general male preponderance in game-playing. Women, on the other hand, used mobile telephones in the bedroom more often than men. This is in line with the finding that young women have a greater rate of talking on the telephone far into the night compared to young men (Suganuma et al., 2007). Previous studies have also found that adolescent girls in general talk more on the telephone than boys (Ohannessian, 2009).

Age was associated negatively with use of all media in the bedroom. This is consistent with previous research (Lucas and Sherry, 2004; Suganuma et al., 2007), and is probably a result of a cohort effect with regard to electronic media use (Palfrey and Gasser, 2008). It is also probably the case that younger adults are more likely to have media devices in their bedrooms than somewhat older adults.

The respondents who used a computer or a DVD player and listened to music in the bedroom ‘often’ reported higher levels of anxiety compared to respondents who used those media in the bedroom ‘rarely’. A possible explanation for this is that individuals with high anxiety levels use media as a behavioural distraction to ease uncomfortable thoughts at night (Ree et al., 2005). Depression was correlated positively with using a DVD player in the bedroom. This may also be because depressed individuals watch movies or TV series at night as a means of self-distraction to help them fall asleep (Ree et al., 2005).

The results showed that women reported that they turned off the lights earlier on weekdays and at weekends/days off, and rose earlier at weekends/days off compared to men. This is consistent with findings that women prefer to wake up and go to bed earlier than do men (Adan and Natale, 2002). No gender difference was found for rise time on weekdays, however. This is probably because rise time on weekdays is controlled by external factors to a greater degree (e.g. work regulations) compared to at weekends/days off. Women also reported more symptoms of insomnia than did men, which is consistent with previous findings (Ford and Kamerow, 1989; Sivertsen et al., 2009; Zhang and Wing, 2006). Age was associated negatively with time for turning off the lights at weekends/days off, rise time at weekends/days off, hours sleep on both weekdays and at weekends/days off, and the magnitude of the discrepancy between weekdays and weekends/days off concerning time for turning off the lights and rising. These results are consistent with previous findings showing that very young adults have a later mid-point for sleep than somewhat older adults (Roenneberg et al., 2004). The current study, however, found no significant relationship between age and symptoms of insomnia. This runs counter to studies which have shown that the prevalence of insomnia increases with age (Sivertsen et al., 2009). The reason for this disparity in findings is due probably to the fact that the age span in our study was relatively restricted.

Both anxiety and depression were associated with poor sleep habits and symptoms of insomnia. This has also been found in numerous studies (Ford and Kamerow, 1989; Sivertsen et al., 2009; Taylor et al., 2005), and underlines the point that anxiety and depression should be controlled for in studies of media use and sleep. After controlling for gender, age, anxiety and depression, respondents who used a computer in their bedrooms ‘often’ compared to ‘rarely’ reported more variability in their sleep schedules. They rose later on weekdays and at weekends/days off, turned off the lights to go to sleep later at weekends/days off, slept more hours at weekends/days off and had a greater discrepancy between turning off the lights to go to sleep on weekdays and at weekends/days off. Previous findings have also shown that computer use at night is associated with poor sleep habits among adults. It has been suggested that computer use in the evening/night postpones going to bed (Suganuma et al., 2007). It is also possible that computer use induces pre-sleep cognitive activity, which may have an alerting effect (Harvey, 2000). Using a computer in the bedroom ‘often’ was, however, not associated with an increase or decrease in the number of hours respondents slept on weekdays, nor was it related to symptoms of insomnia. Similarly, respondents who reported using a mobile telephone in the bedroom at night ‘often’ compared to ‘rarely’ also reported that they turned off the lights to go to sleep later on weekdays and at weekends/days off, and rose later at weekends/days off. However, they did not report more or fewer hours of sleep on weekdays or at weekends/days off, or more symptoms of insomnia.

In summary, it seems that the use of computers and mobile telephones, particularly, in the bedroom is associated with poor sleep habits, as variation in sleep–wake schedules are likely to have detrimental effects on both sleep quality and wakefulness during the day (Dijk and Czeisler, 1995; Stepnaski and Wyatt, 2003; Wyatt et al., 1999). Hence, excessive use of computers and mobile telephones in the bedroom may cause delayed sleep phase. Studies have shown that delayed sleep phase may impair academic and work performance, in addition to social and family life (Alvarez et al., 1992). Delayed sleep phase has further been linked with depression (Kripke et al., 2006). Use of computers and mobile phones in the bedroom might indirectly, therefore, impair health, social and working/academic life. Further studies, preferably with longitudinal designs, should be conducted in order to investigate these relationships more precisely.

There was no difference between watching television, using a DVD player, playing games or listening to music ‘often’ and ‘rarely’ and sleep habits or symptoms of insomnia. It could be the case that such media use does not provide sufficient cognitive activation to curtail sleep onset (Harvey, 2000). However, further research that considers the content and activating properties of television programmes, movies, games and music should be conducted in order to investigate further the relationship between media use and sleep.

Strengths and limitations

The current study focused on the frequency of use of media, and not volume, i.e. the duration of media use. This is an important distinction, and care should be taken in generalizing our findings from frequency of media use to volume of media use. Frequency of media use may pertain more to the degree to which respondents have a habit of using media in the bedroom, while volume of media use may pertain more to how much time the media use displaces. In addition, volume of use may also be associated with the degree of cognitive activation that individuals experience, which in turn may affect sleep habits and/or insomnia. Future studies may therefore benefit from measuring both frequency and volume of media use in order to investigate their relative contributions to sleep habits and insomnia.

The current study was based on a cross-sectional design, hence no conclusions about cause and effects can be drawn. Nevertheless, we controlled for gender, age, anxiety and depression in the regression analysis, thereby precluding such central confounders from influencing our findings. The response rate was low, hence estimates of population parameters are associated with some uncertainty. However, several studies have emerged showing that a low response rate does not necessarily have a significant impact on the results (Curtin et al., 2000; Keeter et al., 2006). It should also be noted that the primary aim of the present study was to estimate relationships between different parameters and it is assumed that non-response has less influence on associations between variables than estimates of a single population parameter (Curtin et al., 2000). A strength of the current study is the relatively high number of respondents. As far as we know, this is the first study which has investigated the relationship between media use in the bedroom and sleep habits and insomnia in a general population sample.

Conclusions

  1. Top of page
  2. Summary
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusions
  8. References

The results of our study suggest that the use of computers and mobile telephones in the bedroom, but not watching television, using DVD players, using game consoles or listening to music in the bedroom, may be associated with poor sleep habits among adults, but not with symptoms of insomnia.

References

  1. Top of page
  2. Summary
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusions
  8. References
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