Active lifestyle may help reduce depression in adolescents

Sedentary behaviour displaces light activity throughout adolescence and is associated with a greater risk of depressive symptoms at 18 years of age, according to results of a recent study done in Southwest UK.

In the study, a significant reduction in total physical activity, measured as count per minute (CPM), was seen in adolescents between 12 years and 16 years of age (12 years, mean: 603.32 CPM; 16 years, mean: 474.83 CPM; p<0.0001). This was driven by decreasing durations of light activity (200–3599 CPM; eg, slow walking) (12 years, mean: 325.66 min/day; 16 years, mean: 244.94 min/day; p<0.0001) and increasing sedentary behaviour (≤199 CPM; eg, lying or sitting still) (12 years: 430.99 min/day; 16 years, 523.02 min/day; p<0.0001). [Lancet Psychiatry 2020;7:262-271]

Higher total physical activity (incidence rate ratio [IRR], 0.981; 95 percent confidence interval [CI], 0.963 to 0.100; p=0.0454), time in sedentary behaviour (IRR, 1.047; 95 percent CI, 1.014 to 1.081; p=0.0052), and time doing light activity (IRR, 0.949; 95 percent CI, 0.916 to 0.983; p=0.0040) were significantly associated with baseline depression measured by the short Moods and Feelings Questionnaire (MFQ) score, with adjustment for multiple covariates.

Sedentary behaviour increased by 11.1 percent, 8.0 percent and 10.7 percent among adolescents at 12 years, 14 years and 16 years of age, respectively. The increase was associated with higher Clinical Interview Schedule-Revised (CIS-R) depression scores at 18 years of age.

In contrast, CIS-R depression scores were lowered with an increase in light activity at 12 years, 14 years and 16 years of age (12 years: IRR, 0.904; 95 percent CI, 0.850 to 0.961; p=0.0012) (14 years: IRR, 0.922; 95 percent CI, 0.857 to 0.922; p=0.0299) (16 years: 0.889; 95 percent CI, 0.809 to 0.974).

Compared with adolescents with persistently low levels of sedentary behaviour, those with persistently average and persistently high levels of sedentary behaviour had 24.9 percent and 28.2 percent higher depression scores, whereas depression scores were 19.6 percent and 31.1 percent lower in adolescents with persistently high levels of light activity and moderate-to-vigorous activity (≥3,600 CPM; eg, brisk walking or jogging), respectively.

There were no interactions between physical activity or sedentary behaviour and sex, and consistent results were demonstrated in sensitivity analyses.

In this population-based cohort using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), adolescents with at least one accelerometer recording on the amount of time spent in sedentary behaviour and physical activity (light or moderate-to-vigorous) at around 12 years, 14 years, and 16 years of age, and a CIS-R depression score at 17.8 years were included. Total physical activity measured by raw accelerometer counts averaged over 60s epochs.

“Increasing light activity and decreasing sedentary behaviour during adolescence can be an important target for public health interventions aimed at reducing the prevalence of depression,” concluded the researchers.