2.1. Study Design
SECONDARY, LARSEN
COMPLETE is a school-based, three-armed longitudinal cluster RCT in sixteen upper secondary schools located in four counties of Norway. Through the measures of DSP and MHST, the aim was to facilitate systematic work on the psychosocial learning environment and follow-up of pupils. We the evaluated the effectiveness of the DSP and MHST interventions from year one (Y1) to year three (Y3) on students’ perception of the psychosocial learning environment, mental health, and academic adjustment. Teacher support, classmate support, a caring school climate, psychological distress, and life satisfaction were measured using commonly accepted scales and questionnaires. There were three study groups: two intervention groups and a control group. The trial started in August 2016 and ended in June 2019. It followed the students from their commencement of upper secondary school to graduation. This study was unblinded (see Larsen et al. [