"Previous comparison of change in CAPS score between sertraline and placebo showed effect sizes of 0.31 and 0.37 (ref. 16). Similarly, comparison of change in CAPS score between paroxetine and placebo showed effect sizes of 0.56, 0.45 and 0.09 (ref. 16). By contrast, the effect size of 0.91 demonstrated in this study between MDMA-assisted therapy and placebo with therapy was larger than that for any other previously identified PTSD pharmacotherapy. "
What exactly does the effect sizes 0.45 and 0.09 mean? Is 1 considered everyone and the .45 is the percentage that the control worked on?
I am writing a speech for my class in which im talking about research studies regarding Psychedelics. I speaking about how the studies were conducted and the results of the studies.