As effects varied between studies, further analyses focused only on controlled trials: MCT had large effect sizes compared to control groups, both immediate and at follow-up, on quality of life (g = 1.02, SE = 0.06; g = 1.06, SE = 0.12) and psychological stress (g = 0.94, SE = 0.07, p < 0.01; g = 0.84, SE = 0.10).