How Psychotherapy Changes the Brain

Maybe you work at a law firm in Washington, DC and you've been turning over a quiet question: would sitting down with a therapist every week actually do anything for you, and is the price tag justified? Research out of Massachusetts General Hospital speaks to exactly that. The investigators found reason to believe psychodynamic psychotherapy can repay the time and money people put into it, and, more unusually, they found hints about who it tends to work for.

A bit of background for anyone weighing it. Psychodynamic psychotherapy sits alongside cognitive behavioral therapy and interpersonal therapy as one of the three principal approaches to depression. CBT concerns itself with how a person thinks. Interpersonal therapy keeps its attention on relationships. The psychodynamic route goes somewhere else entirely, toward the unconscious: the feelings and thoughts a person isn't fully aware of, with the aim of building self-awareness over time. Treatment can run anywhere from a few months to beyond a year, which is part of why the question of whether it's worth it comes up at all.

What the MGH team saw is that patients in this kind of therapy showed real shifts in brain metabolism. That matters because it points to a measurable mechanism, something you can watch happen rather than infer from how a patient says they feel.

The study started with 16 people, each carrying a diagnosis of major depressive disorder and each with a record of medication that hadn't helped. They went through psychological testing first, partly to gauge how deep the depression ran and partly to see how well they could grasp and work through their own emotions, motives, and behavior. Positron emission tomography (PET) scans bracketed the study, one before it began and one about a week after it ended, measuring glucose uptake as a proxy for metabolic activity in the brain.

Everyone received 16 sessions, one a week. The sessions were tailored to the individual but kept to a set theme and order so the study stayed consistent. Under the protocol, sessions were video recorded with consent and reviewed by other members of the team to confirm each one held to the intended structure. Those recordings also let the researchers track how patients responded: whether new insight into their depression emerged, whether self-awareness grew.

Attrition was heavy. Over the 16 weeks seven of the participants left, and nine saw it through. The nine who finished got a second PET scan and another round of psychological testing to measure where their depressive symptoms stood.

The pre-treatment scans zeroed in on the right insula, a region tied to emotional regulation that keeps turning up as important in people with depression. The finding there was that the more depressed a patient was, the higher the metabolic activity in that region. A week after the program closed, the nine who completed it showed that activity drop. And the size of the drop tracked with how much insight each person had reached. Symptom relief took a while to arrive, averaging around four weeks in, but by the end patients had cut their symptoms by more than half.

The scans also looked at the right precuneus, an area linked to memory and self-awareness. Participants who went on to finish started out with higher activity there too. Read together, the two findings suggest a physical thread running between how self-aware a person is and how well they take to this therapy and respond to it.

For psychodynamic work to go anywhere, the patient has to bring insight and self-awareness into the room. What this study adds is a way to glimpse, through imaging, whether someone is likely to be receptive before they commit. Given how many treatment paths exist for depression, being able to forecast a good outcome in advance would spare people the months and dollars spent on approaches that were never going to fit them. That said, the role of precuneus activity as a predictor still needs much larger studies before anyone can lean on it.

So the throughline is this: insight and self-awareness move psychodynamic therapy forward, and a brain scan may show how ready a given brain is to engage with it. For an attorney in Washington, DC, that scan could be worth doing.

Laura Wells