For the study, researchers asked 1,043 students between the ages of 18 and 30 at King's College London to complete two questionnaires about their sleep quality and smartphone usage. The findings revealed that around 40 percent of the students could be classified as “addicted” to smartphones -- and those students were more likely to report poor sleep quality.
More than two-thirds (68.7 percent) of students who were defined as smartphone addicts had trouble sleeping, compared with 57.1 percent of those who were not addicted to their device. Those most likely to exhibit addictive behaviors surrounding smartphone usage were those who used their phone after midnight or for four or more hours during the day.
“Our study provides further support to the growing body of evidence that smartphone ‘addiction’ has a negative impact on sleep”, said Dr Ben Carter, a co-author of the paper and senior lecturer at the Institute of Psychology, Psychiatry and Neuroscience at King’s. “The association is still significant even after adjusting for daily screen time use.”
The study found that people who put down their device more than a hour before they went to sleep were less likely to display an addictive relationship with their phone.
“Of those that stopped using their device more than an hour before bedtime, 23.8% exhibited addiction, compared to 42% of those stopping less than 30 minutes before bedtime,” the study authors wrote.
Establishing good sleep habits
Because sleep has such strong ties to mental health problems, the researchers say it’s important for young people to create and stick to a good sleep routine.
“The negative impact of smartphone use on sleep is very concerning from a mental health perspective,” said Dr Bernadka Dubicka, the chair of the faculty of child and adolescent psychiatry at the Royal College of Psychiatrists. “Many young people have struggled with their sleep and mental health during this pandemic and poor quality or insufficient sleep can be both a symptom and a cause of mental health problems.”
Avoiding smartphone usage -- or any LED spectrum light source -- before bed can help keep melatonin levels (often referred to as the “sleep hormone”) where they should be prior to sleep.
“Keeping a good sleep routine is vital for young people’s health and wellbeing and young people should try to limit their smartphone use late at night, for example, by charging their phone in a different room to their bedroom,” Dubicka said.