Teenagers who spend more time on after-school activities and less than two hours of screen time after school are more mentally(心理上) healthy, according to a study published in the journal Preventive Medicine. The new study was carried out by researchers from the University of British Columbia.
The study used information collected from more than 28, 000 seventh-grade Canadian students between 2014 and 2018. The students first answered questions about their usage of screen time after school, including how much time they spent watching TV, Netflix or something else. Then, students reported how many days they had taken part in after-school activities such as sports or arts programmes. After that, researchers asked students to describe their state of mind. For example, when given a statement such as "I start most days thinking that I will have a good day", they could choose to what level they agreed with it on a scale(等级)．
Some of the results were expected, researchers said in the study. Students with no after-school activities usually had high levels of screen time, for example. And they expected girls would score higher on negative indicators(消极指标) of mental health, as earlier research had found that they tended to have higher levels of anxiety compared to boys.
What was noteworthy, researchers say, is that even among students who took part in after-school activities, 46% still went beyond the recommended screen time of two hours. At the same time, 67% of students who didn' t take part in after-school activities also had more than two hours of screen time. Together, this suggests high screen time among teenagers generally.
"The findings suggest that after-school activities are valuable for the happy growing of teenagers, " the study said. "While past studies have proved the importance of after-school activities for social and academic(学业的) development, the present study shows their importance for good mental health results. "
