With the Jacobson and Truax methodology, the proportion of participants was determined who made a clinically significant change on the CES-D from baseline to post-treatment [37]. First, the reliable change was calculated with the reliable change index (RCI). Jacobson and Truax suggest that subjects can be considered to have improved when they shift from a dysfunctional distributionto a functional one, and the reliable change scores exceed measurement error (calculated by dividing the difference between the pretest and posttest scores by the standard error of the measurement). Second, the recovery criterion was defined as a post-treatment score below the cut-off value of 16 for clinically relevant depressive symptoms [38,39]. Because we studied a population with a mild to moderate symptomatology, the mean score at baseline was already at the recovery criterion (M=16.04; range 1–43; S.D.=8.08). A clinically significant change on the CES-D is thus defined as having a reliable change between the measurements, which required a post-treatment score below the cut-off of 16. Participants that had a clinically significant change were either coded 1 (implying a favorable treatment response, ‘success’) or 0 (‘failure’). The binary outcome was used to calculate the odds ratio (OR) using logistic regression. Based on the clinically significant change proportions, the number needed to treat (NNT) was calculated [40]. To provide a more complete representation of the effects of the intervention, the outcomes were also analyzed for intervention completers only (somewhat arbitrarily defined as participants that attended at least 9 sessions).