Children who spend too much time sitting still have a greater risk of depression in early adulthood, researchers have discovered.
The Lancet Psychiatry study revealed an additional 60 minutes of light activity a day at age 12 (such as walking or doing chores) was associated with a 10% reduction in depressive symptoms at age 18.
UCL PhD student Aaron Kandola, the study’s lead author, said the findings show any degree of physical activity that reduces the time people spend sitting down is likely to be beneficial for their mental health.
“We should be encouraging people of all ages to move more, and to sit less, as it’s good for both our physical and mental health,” he stated.
An extra 60 minutes of light activity a day at age 12
led to a 10% fall in depressive symptoms at age 18
The research team used data from 4,257 adolescents, who have been participating in longitudinal research from birth as part of the University of Bristol’s Children of the 90s cohort study. The children wore accelerometers to track their movement for at least 10 hours over at least three days, at ages 12, 14 and 16.
The accelerometers reported whether the child was engaging in light activity, moderate-to-physical activity (such as running or cycling), or if they were sedentary.
Depressive symptoms, such as low mood, loss of pleasure and poor concentration, were measured with a clinical questionnaire.
Between the ages of 12 and 16, total physical activity declined across the cohort, which was mainly due to a decrease in light activity and an increase in sedentary behaviour.
The researchers found that every additional 60 minutes of sedentary behaviour per day at age 12, 14 and 16 was associated with an increase in depression score of 11.1%, 8% or 10.5%, respectively, by age 18.
Those with consistently high amounts of time spent sedentary at all three ages had 28.2% higher depression scores by age 18.
Meanwhile, every additional hour of light physical activity per day at age 12, 14 and 16 was associated with depression scores at age 18 that were 9.6%, 7.8% and 11.1% lower, respectively.
“Worryingly, the amount of time that young people spend inactive has been steadily rising for years, but there has been a surprising lack of high quality research into how this could affect mental health. The number of young people with depression also appears to be growing and our study suggests that these two trends may be linked,” Kandola said.