Study Questions The Effectiveness Of Psychotherapy On Depression

The findings of new research suggest that psychotherapy, also known as talk therapy, may be less effective than what doctors believe them to be. 

In a report published this week in the medical journal PLOS One, researchers indicate that the benefits of psychotherapy are often overstated in medical journals, partly because studies with poor results concerning the talk therapy are rarely published for the community to evaluate.

An analysis of U.S. National Institutes of Health (NIH) funded trials, using psychological treatment for patients diagnosed with major depressive disorder from 1972 through 2008, was conducted by researchers at the VU University in Amsterdam. The findings indicate that when unpublished studies with unfavorable findings are included in the analysis, the psychotherapy effectiveness dropped by one-quarter. This is the same effect seen in pharmaceutical trials of antidepressants, authors noted.

“These findings may overestimate the ‘true’ effect of psychological treatment for depression,” wrote study authors.

In total, the team found 55 studies that focused on the effects of talk therapy, which consisted of mostly manualized approaches; meaning the therapist and patient use a standardized manual to guide the treatment.

Researchers also found the effectiveness of antidepressants to be “empirically” overestimated because of the lack of publication of trials revealing ineffective findings.

Authors Did Not Think Negative Findings Would Be Published

According to the researchers, about 32% of NIH-funded trials are not published because the trials did not find a benefit in psychotherapy. The researchers indicate that the authors of these unpublished studies believed the trials would not have a chance at being published. For the studies never published, researchers requested the data from the investigators.

When Ellen Driessen, lead author of the study, accounted for these unfavorable studies, the benefits of psychotherapy were greatly reduced.

Researchers say this does not mean psychotherapy is not effective for people with depression, but the extent of the effectiveness has been overstated in published literature. Therapies like cognitive behavior and interpersonal therapy are effective, researchers say, but about 25% less effective than previously thought.

Cognitive therapy is used to help people identify self-defeating behavior. Interpersonal therapy focuses on shaping how people interact with others and typically engage in weekly hour-long sessions with a therapist for three to four months.

Doctors have long known journals to exaggerate the benefits of antidepressants by about the same amount, partly for the same reason. However, the new study could offer doctors and patients a better idea of what they can expect from talk therapy, the researchers indicated.

It is estimated that 5 million to 6 million Americans receive psychotherapy for depression every year and many also take antidepressant drugs.

Researchers suggested that some people find relief by simply talking to a knowledgeable doctor about their concerns or depression. The study reveals engaging in well-tested psychotherapy offers an added 20% chance of achieving improvement or lasting recovery. Prior to the analysis, the chances of improvement were thought to be at about 30%.

The difference in effectiveness results in hundreds of thousands of patients who are less likely to benefit from talk therapy.

Researchers say all studies should be published, regardless of the results and funding agencies and journals should archive both original protocols and raw data from treatment trials to better detect reporting bias.

Some critics say this analysis is not the best portrayal of the effectiveness of psychotherapy, especially since the number of trials evaluated was small and different therapies were pooled instead of considered separately.

Researchers call on doctors, guideline developers and decision makers to be aware published literature overestimates the benefits of many treatments for depression.