Changing Minds: An RCT of a Growth Mindset Intervention on Depressive Symptoms and Well-being in Adolescent Girls and Boys

Single session growth mindset interventions can limit the development of depressive symptoms among high school students, yet, few studies have examined whether these interventions affect well-being or differ depending on gender. This study examined the effects of a growth mindset of personality intervention on primary outcomes of depressive symptoms and well-being (i.e., subjective happiness and life satisfaction) in adolescent girls and boys. In a parallel, 2(time) x 2(condition) x 2(gender), randomized control trial using 1:1 blinded allocation, participants were assigned to an experimental (growth mindset of personality) or control intervention (growth mindset of athletic ability). English speaking students in grade 9 and 12 (ages 13–18 years) at three high schools in Ontario, Canada were recruited, and reported depressive symptoms and well-being at baseline and 4-months follow-up. Of 472 participants, 318 participants (58% girls, 60.8% white, M age = 14.9 years) returned for follow-up and were analyzed (experimental, n = 167; control, n = 152). A three-way interaction was identified ( F (1,308) = 6.81, p = .01, η 2 = 0.022) such that girls endorsed reduced depressive symptoms at follow-up in the experimental condition ( d = 0.31), but no such change was observed in boys ( d = 0.07). The experimental intervention had no effect on subjective happiness, and effects on life satisfaction require further investigation. Single session growth mindset interventions may be helpful for depressive symptoms in adolescent girls. Future research should examine longer follow-ups and explore intervention features most applicable to boys. Clinical trial registration #: NCT04133389.