A recent investigation led by Sweden’s Karolinska Institute has discovered that too much screen time negatively influences sleep quality, increasing a teenager’s risk of depressive symptoms – especially in girls.
Study Overview
The study surveyed 4,810 students in Sweden, aged 12 to 16, during the school year and collected data on screens, sleep, and depression levels. The results showed that greater screen time led to worse sleep hours and quality within 3 months. The increase in screen time was often associated with longer sleep onset, which disrupts the circadian rhythms of sleep.
Gender-Specific Findings
The research demonstrated age and gender differences in the associations between screen time, quality of sleep, and depression
Girls: In girls, sleep disturbance mediated 38%–57% of the relationship between screen time and depressive symptoms, indicating that sleep disturbances likely play a larger role in contributing to depression development among female adolescents.
Boys: For boys, screen time also contributed to sleep disturbances; however, sleep disturbances did not subsequently relate to greater depressive symptoms. The researchers argue that, given the lack of sleep, boys may be more inclined to exhibit externalizing symptoms, unlike girls who demonstrate harm through internalizing behaviors.
What Needs to Change
In light of these findings, the Swedish Public Health Agency advised in September 2024 that young people keep leisure screen use to two to three hours a day, to support mental health and sleep.
The study points out that it is important for adolescents to balance their screen time with activities that support improved mental health and sleep in a healthy manner.
