The article was bad, but the study is hard to read. I'm not 100% sure but I think this this blip says scouting potentially has a casual relationship. It shouldn't translate to "Scouts provide mental health boost".
>This study used a prospective cohort design, controlling for many of the factors that might affect participation in Scouts–Guides and later life mental health. Most of these measures were collected in the appropriate cohort sweep. The possibility of residual confounding, particularly due to missing or poorly measured socioeconomic variables, was further examined using three methods, a negative exposure control, an exploration of ‘dose–response’ and a measure of differing regional rates of Scouts–Guide attendance. Although there was no evidence of a dose–response relationship, the other methods supported the plausibility of a causal relationship.
>This study used a prospective cohort design, controlling for many of the factors that might affect participation in Scouts–Guides and later life mental health. Most of these measures were collected in the appropriate cohort sweep. The possibility of residual confounding, particularly due to missing or poorly measured socioeconomic variables, was further examined using three methods, a negative exposure control, an exploration of ‘dose–response’ and a measure of differing regional rates of Scouts–Guide attendance. Although there was no evidence of a dose–response relationship, the other methods supported the plausibility of a causal relationship.