The roles of treatment duration, session frequency, and their interaction were studied in a sample of 156 patients who had terminated psychotherapy or psychoanalysis. The outcome parameters were treatment end-state and posttreatment change with respect to symptom distress, measured by the General Symptom Index from the Symptom Checklist-90 (SCL-90), morale, as indicated by the Sense of Coherence Scale (SOCS) overall mean, and the quality of social functioning, according to the Social Adjustment Scale overall mean, all of them taken for 3 consecutive years after termination of treatment. Growth curve modeling on the basis of covariance and mean structures yielded 5 principal results. First, outcome changed significantly after treatment termination. Second, end-state and posttreatment changes were influenced by duration and frequency but primarily in interaction. Thus, the effects of duration and frequency were conditional on each other. Third, the joint effects on end-state were small and on posttreatment change, small to moderate. Fourth, on the SCL-90 and the SOCS, there were outcome reversals during the posttreatment period such that good end-states deteriorated in the long run, whereas modest end-states improved considerably. Fifth, generally, the findings seemed to favor low-duration/low-frequency and high-duration/high-frequency treatments in this sample.
2002. Vol. 12, no 1, 39-58 p.