Mental health promotion among youth is an empowering, low threshold approach that can create
large public health effects. Adolescents can protect their mental health by their stress resistance
and resilience, which can be increased by physically active, spending little time sitting and getting
enough sleep. These activity-related behaviours are codependent and should be promoted jointly. A
programme targeting these 24-hour activity patterns is lacking. This project proposes to develop
and evaluate a mobile mental health promotion programme for a general adolescent population (12
-18 years) by promoting these 24-hour activity patterns. The intervention will include features
(tailoring, virtual coach, self-regulation) to change proposed mediators of autonomy, competence,
relatedness and self-regulation skills. The mobile app will be tested for its effect on 24-hour activity
behaviours, mediators, stress resistance and resilience, and mental health in a group-randomized
controlled trial. Intervention will be developed in active participation of users and stakeholders.
Content of the intervention will stem from a prospective study (1 month) assessing the relation
between 24-hour activity patterns and stress resistance and resilience, and their mediators.
Measurements will use smart wearables, ecological momentary assessment and surveys. Tailoring,
virtual coaching and self-regulation is novel and the multi-behavioural approach is expected to bring
large mental health benefits.