Australasian Science: Australia's authority on science since 1938

Night Phone Use Harms Adolescent Mental Heath

Late-night mobile phone use by adolescents is directly linked to poor quality sleep, leading to poorer mental health outcomes, reduced coping and lowered self-esteem according to the first longitudinal study that has investigated how night phone use and mental health were connected.

“We have demonstrated how poor sleep is the key link connecting an increase in night-time mobile use with subsequent increases in psychosocial issues,” said lead researcher Dr Lynette Vernon of Murdoch University.

“Heavy mobile phone use becomes a problem when it overtakes essential aspects of adolescent life. In this case, we see issues when it overtakes time set aside for sleep. We found that late night phone use directly contributed to poor sleep habits, which over time led to declines in overall well-being and mental health.”

The research was part of the Youth Activity Participation Study, which surveyed 1100 students from 29 Australian schools annually from Year 8 until Year 11. Students were asked what time of the night they received or sent text messages and phone calls, and their perceptions of their sleep quality. The researchers also investigated adolescents’ symptoms of depressed mood, involvement in delinquency or aggression, and their coping and self esteem over time.

In Year 8, more than 85% of students owned a mobile phone and around one-third of these students reported they never texted or received phone calls after lights out. Three years later, however, 93% of the students owned mobiles and 78% of these Year 11 students reported late night mobile use.

“We found that those teenagers who start out as relatively ‘healthy’ in terms of their late-night mobile use early in high school tend to show steeper escalations in their late-night mobile use over the next several years,” said study co-author Dr Kathryn Modecki of Griffith University. “This means that even when teens appear to have their technology and sleep under control early on, they still require monitoring and education as they mature.”

“Students with high initial levels of night-time mobile phone use also tended to have higher initial levels of poor sleep behaviour,” Vernon said. “As their levels of mobile phone use grew over time, so did their poor sleep behaviour.”

“What is especially compelling,” Modecki added, “is that these increases in poor sleep, in turn, led to rises in depressed mood and externalising behaviours, and declines in self-esteem and coping 1 year later.”

Vernon said that although these results were concerning, the answer was not as simple as just banning adolescent phone use. “These results demonstrate the importance of adults ‘meeting teens where they are,’ enforcing electronic curfews, and teaching good sleep habits during the high school years.”

The study has been published in Child Development.