28 subjects participated in a 6-wk. assertion training program. Of these, 22 remained in the study for a 6-mo. follow-up period, during which half received monthly booster sessions and half did not. Assignment to the booster and no-booster groups was random, with the qualification that subjects were equated on trait anxiety before training in assertiveness. Subjects filled out the Gambrill-Richey Assertion Inventory, the Spielberger State-Trait Anxiety Inventory, and the Zung Self-rating Depression Scale before the 6-wk. assertion training, after this program, at a 3-mo. follow-up, and at a 6-mo. follow-up. It was hypothesized that the booster group would exhibit significant superiority on these measures at the 3-mo. and 6-mo. follow-ups. On all measures both groups significantly improved from before to after the training program with good maintenance throughout the follow-ups. There were no differences between the booster and no-booster groups on the measures of assertiveness and anxiety. However, there was a significant interaction for the depression scores when the booster and no-booster groups were compared from posttreatment to 6-mo. follow-up. The depression scores of subjects in the booster group were lower than the depression scores of subjects in the no-booster group at the 6-mo. follow-up. These results were discussed with suggestions for further research.
