Verbal participation and group therapy outcome.

The relationships between patients speaking out and measured outcome were investigated over 18 months in an out-patient group. The parameters of therapeutic progress were derived from the Symptom Check List and individualized repertory grid rating scales. Each patient's verbal participation was compared to that of other group members and to his own participation over other measurement phases. Speaking out phases were associated with more chance of change and improvement, while silent phases were associated with less chance of change and an increased likelihood of negative change. This study demonstrates the use of a relatively non-disruptive measurement model in testing clinical hypotheses in single psychotherapy groups.