Multidimensional patterns of change in outpatient psychotherapy: the phase model revisited.

In this study, groups of psychotherapy outpatients were identified on the basis of shared change patterns in the three dimensions of the phase model of psychotherapeutic outcome: well-being, symptom distress, and life functioning. Treatment courses provided by a national provider network of a managed care company in the United States (N = 1128) were analyzed using growth mixture models. Several initial patient characteristics (treatment expectations, amount of prior psychotherapy, and global assessment of functioning) allowed for the discrimination between three patient groups of shared change patterns. Those patterns can be classified into three groups as phase model consistent, partial rapid responders, or symptomatically highly impaired patients with each having typical change patterns.