Childhood Lifestyle Behaviors and Mental Health Symptoms in Adolescence.

Importance: Mental health problems often arise during adolescence and early adulthood, affecting up to 25% to 30% of young people. Enhancing the ability to identify children and adolescents at increased risk of mental health problems and uncover factors that promote mental health from childhood to adolescence is important. Objective: To investigate if cumulative lifestyle behaviors from childhood to adolescence are associated with perceived stress and depressive symptoms in adolescence. Design, Setting, and Participants: Prospective cohort study in Finland using baseline data collected between October 2007 and November 2009 and 8-year follow-up data collected between December 2015 and December 2017 as part of the Physical Activity and Nutrition in Children (PANIC) study of children aged 6 to 9 years. Data were analyzed from January to February 2024. Exposures: Cumulative physical activity (PA), sedentary behavior (SB), sleep, and diet quality from childhood to adolescence. PA and screen time (ST) assessed by a questionnaire; PA at different intensities, SB, and sleep duration assessed by a combined movement and heart rate sensor; diet quality assessed by 4-day food records and the Baltic Sea Diet Score computed at baseline, 2-year follow-up, and 8-year follow-up examinations. Main Outcomes and Measures: Perceived stress assessed by the Finnish version of the Cohen Perceived Stress Scale, and depressive symptoms by the Beck Depression Inventory at 8-year follow-up examinations. Linear regression analyses were used to evaluate associations between cumulative lifestyle behaviors over 8 years with the outcomes. Results: Altogether, 187 adolescents (97 boys [51.9%]; mean age, 15.8 [0.4] years) had valid data on self-reported lifestyle behaviors, and 170 adolescents had valid data on device-assessed lifestyle behaviors. Perceived stress scores ranged from 2 to 33 and depressive symptoms scores from 0 to 31. Self-reported total PA and supervised exercise were inversely associated with perceived stress (standardized regression coefficient [β] = -0.15; 95% CI, -0.31 to -0.01 and β = -0.15; 95% CI, -0.29 to -0.01, respectively) and depressive symptoms (β = -0.17; 95% CI, -0.31 to -0.02 and β = -0.14; 95% CI, -0.29 to -0.0, respectively). Total ST (β = 0.27; 95% CI, 0.13 to 0.41), computer use (β = 0.16; 95% CI, 0.01 to 0.30), and mobile device use (β = 0.28; 95% CI, 0.16 to 0.41) were positively associated with perceived stress. Total ST (β = 0.30; 95% CI, 0.15 to 0.44) and mobile device use (β = 0.33; 95% CI, 0.19 to 0.46) were positively associated with depressive symptoms. Conclusions and Relevance: This cohort study of Finnish children and adolescents found that higher PA and lower ST from childhood were associated with perceived stress and depressive symptoms in adolescence. These findings emphasize reducing screen time and increasing PA to promote mental health in youth.