There Is Limited Evidence To Support The Widely Held Belief That Psychotherapy Changes The Body As Well As The Mind


By guest blogger Tomasz Witkowski

Looking at the latest epidemiological data, it could be argued that we are in the midst of a pandemic of mental illness, of dimensions never before seen in human history. The WHO estimates that over 350 million people around the world are presently suffering from depression, which constitutes almost 5-6 per cent of the population. At its extreme, depression may lead to suicide, by which it is estimated that around 1 million people die every year. And the numbers continue growing. Faced with this rising tide of illness, it is impossible to overestimate the importance of hard facts and data indicating the paths researchers and clinicians may follow in search of ways to help. Sometimes, as suggested by a meta-analysis of 50 years of studies on indicators that help predict suicide attempts, we are entirely helpless. In other cases, like with the recent meta-analysis of the neural correlates of the changes brought about by psychotherapy in depressed brains, study results do bring us hope. 

The results of the first systematic review and meta-analysis of biological markers evaluated in randomized trials of psychological treatments for depression in Neuroscience and Biobehavioral Reviews are another attempt at understanding methods of treating this terrifying illness. The authors – Ioana A. Cristea, Eirini Karyotaki, Steven D. Hollon, Pim Cuijpers and Claudio Gentili – quite rightly point out that understanding how psychological interventions impact or are impacted by biological variables has important implications. For many people, their depression co-occurs with a bodily illness, such as cancer, diabetes, heart disease, and immune system and neurological disorders, and at times is a consequence of that illness. Although we still know little about the reciprocal cause-and-effect mechanisms between psychic and somatic symptoms, some studies have suggested that psychological interventions not only change mood, but also normalise the functioning of the autonomic nervous system, with a therapeutic effect on physical conditions, such as heart disease. But is this really true?

The authors analysed fifty-one trials (5,123 adult participants; over half with a somatic disorder alongside depression) where biological markers such as glycemic control, cortisol concentration after-wake, immunological, neurobiological, inflammatory, weight and blood pressure were outcomes (in 43 studies) and/or predictors of treatment response (9 studies). In fact, only one-fifth of the trials reported statistically significant physiological benefits of a psychological intervention over control, and where present, such benefits were restricted to a tiny fraction of the total variables assessed. Although statistically significant, these limited positive effects were very weak. For measures related to glycemic control and cortisol concentration, psychotherapy did not outperform the controls at all. 

The results contradict the broadly held belief that psychotherapy impacts biology. There may be many reasons for this contradiction, but a likely one is that the belief came about on the basis of purely observational evidence (the effectiveness of psychotherapy in depression is measured almost exclusively with patients’ self-reports or clinician-rated scales, assessing symptoms or other subjective outcomes, and it’s possible these subjective ratings have given an exaggerated impression of the biological impact of psychotherapy). 

The authors believe their failure to uncover evidence for psychotherapy having biological effects is most likely due primarily to methodological inconsistencies between studies (there was large variability across the biological domains and markers explored and overall findings were mixed), or to the confounding factors, such as placebo effects, that are so characteristic of studies on the biology of psychological illness. If they are correct, then in time, once researchers solidify their methodology, this will deliver new results that confirm the general belief in the beneficial effect of psychotherapy on disruptions to human biological functioning. However, if the researchers’ explanation is untrue, then the results of their new meta-analysis give rise to very fundamental doubts and questions: Is the dogma of psychophysical unity, presently accepted in contemporary psychology and medicine, correct? Is it possible that any associations which occur are of a solely unidirectional nature (biology modifies our mental states, but not the reverse)? And finally, perhaps the most banal question that would render the others meaningless: is it possible that the belief in psychotherapy’s capacity to alter biological functions in our bodies is nothing more than the product of marketing and hype? 

In seeking the answers to these questions, it is worth examining the manner in which particular types of psychotherapy came about. Were they created and modified on the basis of analysis of feedback (such as biomarkers) supplied by patients’ bodies? And if not, perhaps the issue is not with the methodological imperfections of studies looking for biological effects, but rather in the ways that psychotherapies are developed? To find answers to these questions, we have to analyse the methods that are used to shape psychotherapeutic interventions in the first place. 

Biological markers evaluated in randomized trials of psychological treatments for depression: a systematic review and meta-analysis

Post written by Dr Tomasz Witkowski for the BPS Research Digest. Tomasz is a psychologist and science writer who specialises in debunking pseudoscience in the field of psychology, psychotherapy and diagnosis. He has published over a dozen books, dozens of scientific papers and over 100 popular articles (some of them in Skeptical Inquirer). In 2016, his latest book Psychology Led Astray: Cargo Cult in Science and Therapy was published by BrownWalker Press. He blogs at Forbidden Psychology.

10 thoughts on “There Is Limited Evidence To Support The Widely Held Belief That Psychotherapy Changes The Body As Well As The Mind”

  1. A 15-year depression that resisted treatment via medication was resolved in a single session of psychological treatment. The elderly client manifested persistent negative views of herself as helpless on account of an upsetting event in early childhood involving her mother who was perceived as having blamed her unfairly. (Feelings of helplessness had been re-aroused by a current stressor, which led her to seek psychological treatment). Treatment used was Re-decision therapy: re-visiting the historical event in a kind of imaginary role play and speaking up in a way that she had not done when upset as a child. To me that shows that psychology impacts biology (the neurochemical substrata associated with depression and wellbeing). Recommend reading Goulding and Goulding for Re-decision therapy. My developmental model of how negative experiences impacting on psychological needs are structuralised in memory and manifest as recurring negative thoughts and feelings is also useful.

    1. There should be a ‘laugh’ emoji for this comment. I think you have just demonstrated the totally unscientific bias described in the main article.

  2. It seems psychological therapy can do little to change minds too – except for perhaps the short term relief and or people pleasing that often happens in the therapy room and the seeming unlimited capacity for therapist delusion. Not to mention the huge power imbalance between the perceived expert and client exposing elements of their vulnerability to be fixed.

    Surely by now after all these decades past with hundreds of talk therapies, dozens of drugs and an ever growing list of stigmatizing, largely harmful diagnostic labels we can see we are looking in the wrong place for the problems and the fix?

    We are in a constant state of dynamic interaction with our world inner and outer most of which is beyond our awareness, driven by drives unseen and out of our control, free will ain’t so free it seems.

    What is clear to see are the cultural disorders harming most of us – most jobs, debts, non existent communities, consumerism, advertising, disconnections from nature, self and others, from meaning and purpose, rubbish foods, dependencies abound, stressed, bored, tired, alienated, no control, fear based media, lies and propaganda, shift work, barely any control and variety in life and on and on – perhaps if we started to accurately diagnose the cultural disorders we might stand a chance of creating healing and life affirming environments but no we’ve an army of often well meaning but self interested people in the therapy industry with mortgages to pay status to seek and illusions to maintain.

  3. In order to understand whether psychological changes translate to biology, why is it that this study did not assess things like structural changes in the brain (amygdala volumes that is significantly related to stress). Decades of research have demonstrated that the organization of the brain is constantly changing as a result of our experiences (neuroplasticity) – so, it is well known that biology changes with psychological changes. I would think that the outcomes that these authors have specifically selected to assess (things like blood pressure) would take a long time to change. I also do not see whether the authors specifically looked at the duration of the studies.

  4. Did any of the studies analyzed look at body-based psychotherapies or cognitive based therapies? In my own practice I’ve seen more significant changes with body-based therapies versus CBT oriented approaches.

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