Sunday, December 14, 2008

Meditation vs Medication

By Guest Blogger, Redlan.

Media reporting of science is a beautiful thing to behold, and usually dreadfully and woefully wrong. Read the original study and you are pretty much guaranteed to find that the study found almost the complete reverse of what was reported.

The Daily Mail recently reported that "Meditation 'as effective as medication' in treating depression" and the BBC followed with "Group Therapy 'beats depression'"

As effective? Beats depression?

On this one they might have redeemed themselves though, as they’re both only half wrong. What they are talking about is something called Mindfulness-Based Cognitive Therapy or MBCT. Sounds really sciencey if we just use letters. It’s a form of CBT (cognitive behaviour therapy) which is a therapeutic technique that aims to correct behaviours, emotions and thoughts through a goal-orientated approach. It’s actually an umbrella term for a group of cognitive and behavioural approaches, of which MBCT is one. The paper that prompted both the headlines is Mindfulness-based cognitive therapy to prevent relapse in recurrent depression by Kuyken et al from the University of Exeter.

The 'meditation' bit comes about because the therapy uses some meditation techniques. But do not be fooled - MBCT isn’t meditation, it’s a therapy. We’ll deal with the Daily Mail headline a bit later. Never mind whose meditation techniques it uses, does it actually work? For now let’s look at the results:

The Daily Mail and the BBC don’t quite agree on how effective it is. The Daily mail says
47% of people with long-term depression who underwent the therapy suffered a relapse, compared to 60% of those taking anti-depressant drugs.
And the BBC says
The trial of 123 people found similar relapse rates in those having group therapy and those taking drugs.
So what’s going on? The Daily Mail seems to imply that MBCT is better, while the BBC says they are similar. Is 47% really similar to 60%?

The abstract says
MBCT were 47%, compared with 60% in the m-ADM group (hazard ratio = 0.63; 95% confidence interval: 0.39 to 1.04)
The Daily Mail got the numbers right. What about the stuff in brackets? The hazard ratio is similar to, but not the same as relative risk. In this study the hazard ratio is a measure of the effect of MBCT on relapse rates. The 95% confidence interval is an estimate of the hazard ratio you would get if you repeated the experiment. But there is something missing…

Why haven’t they quoted the statistical significance usually denoted as p? Did they forget? Or not think it was very important?

Statistical significance is used to test the null hypothesis – i.e. the hypothesis that there is no effect. I worked out p using chi-squared test of significance. I got p=0.12. Normally in biomedical sciences p<0.05 is considered to be significant, and so by that standard we have a null result. In other words, for this experiment, 47% is not significantly smaller than 60%. So the BBC would appear to have got it right. Hurrah for the BBC!

The NHS website, Behind The Headlines, also discusses this paper. It rightly points out the flaws in the BBC’s and Daily Mail’s reporting. It then goes on to give a few more details about the study. The subjects had received MBCT treatment for the previous six months and were now in either full or partial remission and taking antidepressant medication. There were then randomised to receive a further 8 week course of MBCT or treatment as usual, which meant continuing with anti-depressants. The treatment arm were also offered support to withdraw or lower medication.

So what exactly is this a study of? The rather innocent sounding (though wordy) title of Mindfulness-based cognitive therapy to prevent relapse in recurrent depression, doesn’t really do it justice.

So which one is the control group? Which event do you think might have the biggest impact amongst people with depression? Being told that you were going to get another course of MBCT? Or being told that you weren’t going to get one? Participants would have to be willing to participate in another course of MBCT before they could be enrolled in the study.

In the field of mental health, the placebo effect is very pronounced. It is typically damned hard for pharmaceutical companies to demonstrate that their latest mood enhancing wonder drug works any better than the placebo. Tell someone that they are going to receive “therapy” to make them better, and lo and behold they start to get better.

Read the literature and you will find that CBT is described as a useful addition to normal drug treatments. So bearing in mind that the placebo effect is very pronounced, what are all these treatments tested against in the control group? Sham therapy? Self help groups? Going to the pub with some friends?

Nope.

They are all compared to treatment as usual, which usually means treatment with anti-depressants. So the effect could simply be down to the “therapeutic relationship” and nothing to do with the actual therapy. It’s not the therapy that’s making you better, it’s the hour a week you have with your “specialist” telling you that his therapy will make you better, that is making you better.

Patients getting CBT do better than patients who don’t get CBT, but is it the CBT itself, or the therapeutic relationship that is making them better? It's impossible to tell, until someone devises a placebo based control group. I haven’t found one, but then I don’t have the resources to run systematic searches and analyse the results. If you have a spare afternoon, I guess you could have a some fun searching PubMed.

Now back to that Daily Mail headline…

Meditation 'as effective as medication' in treating depression

Really? Is meditation as effective as medication? Well, probably not according to the Cochrane Library. They did conclude that meditation was better than no or minimal treatment on self-related depressive symptoms, but not as good as psychological treatments. So it would appear that patients believe that psychological treatments work better than meditation, which works better than nothing. However doctors weren’t quite so sure - the doctors only noticed a non-significant trend that meditation was better than nothing, and they couldn’t tell the difference between psychological treatments and meditation.

Newspapers and the media like to sell us simple stories. If they resonate with a strongly held social belief, then all the better. Usually the real picture is more complicated, and whether we like it or not the “experts” often do not know the answers. What is lost sometimes in the story is the fact that science is not neutral or unemotional or unbiased. It is after all perpetrated by humans. So let’s just ask a couple questions…

Why would the researchers of the paper behind the headlines, neglect to mention whether the result was significant or not in the abstract?

I wonder if they would have mentioned p if the result had been significant? It’s normal practice to state whether the result was significant or not. Try finding a paper without p being mentioned. I do find the paper confusing, because I can’t work out what hypothesis they are testing. Maybe they don’t mention p because the study appears to be designed to produce a null result anyway.

Why is CBT always tested against Treatment as Usual (TAU)? Sure it may be hard to devise and agree on what would constitute a proper placebo, but how else are you going to know whether CBT is not simply itself a placebo? I guess though you’d have to be brave to design a study knowing it could end up disproving years of training and research.

Of course, that's no reason not to do it.
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Redlan
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BPSDB

9 comments:

  1. Good analysis - I was going to post about this myself but other things seemed more pressing.

    I'm usually very skeptical of wild claims on behalf of psychotherapy and you're quite right that it's difficult to exclude the possibility that the whole of CBT is a placebo effect. I think there's an interesting case to be made that actually it doesn't matter if it is, because if it works, it works - and a lot of psychotherapy (including CBT) aims at boosting confidence and making the patient believe that they can get better, which is exactly what placebos do.

    I think CBT (and indeed MCBT) probably is, largely, a placebo but that's not necessarily a bad thing.

    Also it's important to note that these patients were a very select group. They had suffered from highly recurrent depression - which is quite unusual - and they were all keen to quit their antidepressants. Quite possibly because they weren't working very well for them (or they just weren't taking them - you'd be surprised how often this happens). In otherwise this is probably a group of people for whom many things might be better than drugs, not just MCBT.

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  2. "In the field of mental health, the placebo effect is very pronounced.":

    It's more than a placebo effect, because a proportion of people with symptoms of affective disorder at a given time will be better at some later date. (If you have a cold today, you will probably be better 10 days from now.)

    Having said that, care and attention play a large part in any therapy for psychiatric illness. Lithium is astonishingly effective in bipolar disorder, which clearly has a very strong physiological component. However, your success rate is sure to be low if you just tell patients to take the tablets, particularly if they have been ill for a long time.

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  3. COMPREHENSIVE VIEW OF SCIENCE OF RELIGION (THEOLOGY)

    Yoga (Application) which was based on the control of the body physically and implied that a perfect control over the body and the senses led to knowledge of the ultimate reality. A detailed anatomical knowledge of the human body was necessary to the advancement of yoga and therefore those practising yoga had to keep in touch with medical knowledge. (Romila Thapar, A History of India, volume one).

    I suggest : Mind and brain are two distinct things. Brain is anatomical entity whereas mind is functional entity. Mind can be defined as the function of autonomic nervous system (ANS). It is claimed that mind can be brought under conscious control through the practice of meditation. But how? ANS is largely under hypothalamic control which is situated very close to optic chiasma (sixth chakra or ajna chakra). Protracted practice of concentration to meditate at this region brings functions of ANS say mind under one’s conscious control.

    ANS is further divided into parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS). On the basis of these facts I have discovered a mathematical relationship for spiritual quotient (S.Q.). Spiritual Quotient can be expressed mathematically as the ratio of Parasympathetic dominance to Sympathetic dominance. PSNS dominates during meditative calm and SNS dominates during stress. In this formula we assign numerical values to the physiological parameters activated or suppressed during autonomic mobilization and put in the formula to describe the state of mind of an individual and also infer his/her level of consciousness.

    Protracted practice of meditation under qualified guidance will help to manage all sort of psychological problems.

    Emotional Quotient can also be expressed mathematically as the product of I.Q. and Wisdom Factor.

    Anirudh Kumar Satsangi

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  4. As I read through your post, it occurred to me that perhaps therapy works (or appears to work) better than medication because there is human interaction involved. This is generally what a depressed person wants: some form of human intimacy.

    I personally think the over-simplification of psychological problems and medication is more appalling between doctors and patients.

    Depression, bi-polar, anxiety are all explained as "a chemical imbalance in the brain." Ok. What chemicals? And what would be balanced? Compared to whom?

    Most important: HOW does anyone know this simply by asking a person a series of questions about their life? Is that really empirical evidence?

    It is possible that not all psychological problems can be reduced to biological terms. It may not even be helpful. It doesn't seem to be so far.

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  5. Attempts have been made to separate placebo effects from therapy - but they tend to show that unconscious bias always creeps into the experiment. For example, trying a 'real' therapy against a 'fake' therapy doesn't work because the experimenters know which one they are applying and unconsciously favor the 'real' one - double-blind is impossible.

    Also, it has been found that unconscious bias makes comparisons of therapies impossible - for example if CBT-trained therapists compare CBT v. another therapy, CBT always wins. However, if psychodynamic-trained therapists compare psychodynamic v. another therapy, psychodynamic always wins. This is true even if the experimenters are sincere and dedicated to finding the empirical truth - the bias is unconscious.

    So, as yet, no one has come up with a way of separating therapeutic approaches from each other or from placebo.

    This doesn't change the one thing we do seem to know - that talking therapies are better than nothing and for most people better than drugs. We just don't know why.

    See for example, Mick Cooper "Essential Research Findings in Counselling and Psychotherapy" for a lay introduction to current research in this area.

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  6. It always seems to me that the word "placebo" has rather negative connotations. The "placebo effect" is rather complex and results in measurable physiological changes. As neuroskeptic says, if MCBT and CBT work through the same processes as are seen with placebo tablets so what?

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  8. Hi Redlan,

    As a footnote to your piece, it might be worth noting that a study with a 95% CI that spans 1.0 is equivalent to a study not being significant at the 5% level (p>0.05).

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  9. Anirudh Kumar SatsangiJuly 29, 2010 at 1:34 AM

    Meditation is highly cost-effective and without any side effects if practiced under qualified meditation instruction. The practice of meditation is most effective if we practice to concentrate to meditate at optic chiasma (sixth chakra according to Yoga System.)

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