Dr David Tuller: Trio of Trials Shows Limits of CBT for Medically Unexplained Symptoms


Senior Member

Trial By Error: Trio of Trials Shows Limits of CBT for Medically Unexplained Symptoms

17 JUNE 2020
Lancet Psychiatry recently published the results of a high-profile trial of cognitive behavior therapy as a treatment for so-called dissociative seizures, also known as psychogenic non-epileptic seizures. The trial, nicknamed CODES, found that CBT had no impact on seizure frequency–the primary outcome. The average number of seizures per month dropped in both the treatment and comparison groups, with no statistically significant difference between them.
With this study, British investigators from the so-called biopsychosocial (BPS) camp have completed an impressive trifecta of major, presumably definitive trials of CBT as a treatment for so-called “medically unexplained symptoms” (MUS). The others include the PACE trial for cognitive fatigue syndrome, with key results published in 2011 and 2013, and a trial for irritable bowel syndrome, with results published last year.
As a group, this trio of trials demonstrates the ineffectiveness of cognitive behavior therapy as a treatment for the kinds of MUS targeted by the UK National Health Service’s Improving Access to Psychological Therapies (IAPT) program. The metastasizing IAPT program began a decade ago to boost mental health care for those suffering from depression and anxiety. It has since expanded to offer psychological treatment to patients with long-term conditions, such as cancer and multiple sclerosis, and those diagnosed with MUS.

Northwestern University law professor Steven Lubet and I have recently published a commentary on the need for humility in making categorical statements regarding conditions of unknown etiology. And a recent series of articles on the advocacy site Opposing MEGA has highlighted estimates of high misdiagnosis rates for various subgroups of MUS, although proponents of the construct tend to downplay or ignore these data.

As is well-known, the PACE trial reported benefits from CBT that turned out to be largely illusory, according to reanalyses of the study’s main findings. (I was a minor co-author on the main paper debunking the findings.) The lead investigators weakened their outcome measures for improvement and recovery, providing inadequate and even laughable reasons for having abandoned their own protocol methodology.

In any event, the international community has spoken on PACE. An open letter to The Lancet, signed by more than 100 scientists, clinicians and other experts, denounced the study’s “unacceptable methodological lapses,” and the US Centers for Disease and Control and Prevention has removed recommendations based on the trial.