The goal of this action research project is to develop and implement nature- and activity-based group interventions across health care, school and leisure settings in Southern Norway. The interventions are tailored to support the mental health, self-efficacy and daily life functioning of children and youth in the Agder region, with a particular focus on youngsters who struggle due to neurodivergence, such as Attention Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD) or Tourette's syndrome. The main questions we aim to answer are: 1. To what extent does nature- and activity-based outdoor education contribute to improvements in children's quality of life? 2. To what extent does nature- and activity-based interventions in a health care setting improve children's self-efficacy, self-esteem and quality of life? 3. Is there a difference in physiological reactions between nature-based provision of education or therapy and traditional indoor provision of education or therapy? Participants will take part in a 12-week school-based or health care intervention.