Outcomes from 40 years of psychotherapy in a private practice.

Of 1,969 patients seen by a clinical psychologist during 40 years of private practice, at the time the outcome data were analysed 1,374 were either in treatment or had completed treatment and all of these cases had produced outcome data. The results show that four (4) patients (0.29%) became Much Worse, 10 (0.73%) became Worse, 412 (29.96%) showed No Change, 467 (33.96%) became Better, and 482 (35.06%) were Much Better. The mean treatment effect size (ES) was 1.87. Outcome varied significantly across diagnostic categories. Outcome also varied by age groups. Outcome for males and females did not differ, but both kinds of individual patients did better than when couples were the focus of treatment. The dropout rate was 17%. The mean number of sessions per case was 17.43, the median was 10, and the range was 1 to 344. There was a significant positive correlation between number of treatment sessions and outcome. The therapist's effectiveness did not improve across the years. Managed care had a significant negative impact on treatment outcomes.