"Playboy: Psychology and psychiatry are not exact sciences, so it’s difficult to determine what effect they have. How can you tell if you’ve helped a patient?

Peck: There was one study in which researchers took one group of people and put them into therapy, while refusing therapy to a control group. Three or four years later, they found that the patients who hadn’t had therapy were just as healthy as those who had. However, about ten years after the study, somebody decided to look again. They found that there was a remarkable difference between the treated group and the untreated group. The group that had had therapy had more variability. Some were far more healthy, and some were far more unhealthy than they had been.

Playboy: What do you conclude?

Peck: Well, they traced it further to particular therapists. Good therapists made people better. Bad therapists made people worse."
-----

This strikes me as nonsensical. There are far too many confounding variables, especially over the course of years. Every therapy patient has a unique set of life circumstances. They are not living in laboratory where variables can be controlled. His rationalization about good vs bad therapists is ridiculous. He's trying to defend his profession by segregating the "bad" ones. And who made the classification of good vs bad? That's a completely subjective value judgement. Everything he describes is totally unscientific.

And in the "treated" group, what was the breakdown of more healthy vs less healthy?