Effective Therapy is About Making Mistakes

Written by Jon Hook

How do we know therapy is effective?

It’s easy to assume psychotherapy works like medicine: you match the right treatment to the right disorder, and outcomes improve. But decades of research show something more complex. The biggest driver of change isn’t which therapy you practice—it’s how well you do it. Therapist skill alone predicts up to nine times more variance in client improvement than the choice of technique. This does not mean that techniques do not matter (in some cases, we have identified exacting behavioral processes of change like exposure) but points to a larger insight which is that how we do therapy is inextricably bound with what we're doing.

That raises uncomfortable questions: If expertise matters more than interventions, why haven’t outcomes improved despite the explosion of therapies and training programs? Since we began measuring therapy outcomes in the 1980s, we have developed thousands of new and cutting-edge treatments, and yet the overall effectiveness of therapy has remained the same. And why do therapists with more credentials and years of experience often get results no better than trainees?

The myth of expertise

Psychology still runs on the assumption that experience and education naturally translate into better results. The evidence doesn’t back this up. In fact, outcomes often plateau early in a therapist’s career, and in some studies, trainees have equaled or even surpassed seasoned professionals. Traditional supervision—our main vehicle for transmitting expertise—has also failed to show consistent links to improved client outcomes.

If therapy effectiveness isn’t guaranteed by years in the field, how do we actually get better?

Feedback as the game-changer

Here’s where feedback comes in. Research shows that therapists who regularly ask clients about their progress and the quality of the therapeutic relationship get better results. Using structured outcome measures and alliance feedback—what’s often called Feedback-Informed Treatment (FIT)—has been shown to boost outcomes by up to two times. This means fewer dropouts, less deterioration, and happier clients.

But here’s the twist: the best therapists aren’t the ones who collect glowing reviews session after session. They’re the ones who get worse feedback. Why? Because their clients felt safe enough to tell them that what was happening in the room wasn’t working. That honesty gave these therapists a chance to adjust, repair, and try again. In other words, progress came not from avoiding mistakes but from making mistakes visible—and then using them.

Out in the natural world of therapists, researchers have identified “supershrinks” who help their clients improve at rates ten times faster than average. What sets them apart isn’t a secret technique or a polished manual—it’s their intuition that therapy only works if you know how the other person is actually experiencing it. Many of these therapists weren’t even aware of their unusual effectiveness, nor did their “bag of tricks” look especially impressive. In a training I attended, Scott Miller (creator of FIT) told me directly that “some of their tapes looked like shit.” They weren’t measurement-obsessed or rigidly tied to forms; feedback for them was not a series of forms and tools, but a lived practice of checking in, noticing, and adjusting. They somehow grasped the importance of getting accurate, real-time feedback and responding to it. In practice, they closed the gap between what they thought was happening in therapy and what their clients were actually living.

Why feedback really matters

FIT and ROM aren’t magic tools. They don’t cure depression or anxiety on their own. Their power lies in making the therapeutic relationship open, working, and correctable. They help therapists notice when clients are drifting, when the alliance is shaky, and when what’s happening in the room isn’t actually helping.