There was good news last week about the effectiveness of mindfulness meditation for easing anxiety, depression and pain. Mail Online reported that a study had found “meditation ‘works just as well as anti-depressants’: half an hour a day offers as much relief as tablets”, while The Boston Globe said those who took mindfulness classes experienced improvement in mood after eight weeks “on par with the effect seen with prescription medications”.
This was all perfectly true. A review published in JAMA Internal Medicine had looked at all the best studies to date and concluded that there was “moderate evidence” of improved anxiety, depression and pain among patients. The effect on mild depression was indeed equal to that achieved with anti-depressants.
Like me, though, you may be a bit underwhelmed by that phrase “moderate evidence”. It’s hardly a ringing endorsement, but better than “low evidence” – which was what the reviewers concluded about the efficacy of meditation for improving stress/distress and mental health-related quality of life.
Nevertheless, this was one of the most rigorous reviews of the available evidence ever conducted, so “moderate” or even “low” evidence represents a solid endorsement. What it suggests is that, given more time and high-quality research, we may be able to say with certainty that patients with mild depression will benefit just as much from a course of meditation as they would from a course of medication. For those who want an alternative to taking pills, who have failed to benefit from them, or who have experienced unpleasant side-effects, meditation may well be worth trying.
Dig a little deeper into the research, though, and you find that there was some evidence to suggest that meditation had no effect on positive mood, attention, substance use, eating habits, sleep and weight. This is obviously disappointing, because mindfulness therapy had seemed like a promising way to tackle ADHD (attention deficit hyperactivity disorder), drug dependence, eating disorders and insomnia, in addition to improving overall mood.
Why didn’t the review find any evidence that meditation can offer benefit in these conditions, when so many studies over the past decade have suggested that it can? And why isn’t there stronger evidence for its efficacy in depression, anxiety and pain?
Setting the bar high
There are two possible reasons. The first is that the review used strict selection criteria to decide which studies were worthy of inclusion in its analysis, and which studies were simply not rigorous enough to provide reliable evidence. The criteria included not only things like whether there were enough subjects to provide valid results, but also whether the therapy was compared with an “active control”. In other words, there had to be a comparison group who were given some kind of equivalent activity in terms of patients’ time, attention and expectation, or an alternative intervention such as education or progressive muscle relaxation.
Control groups like these are vital because of the power of the placebo effect. So, for example, if your control subjects are simply put on a waiting list to receive meditation training, they’re not providing a fair comparison. The placebo effect – the mysterious improvement in medical conditions seen in patients simply because they believe they are being given a worthwhile treatment or intervention – must benefit both the people getting the experimental treatment and the controls equally.
Amazingly, only 3% (47) of the studies they reviewed met their criteria. A commentary written to accompany the research paper suggests that research into alternative therapies is hard to fund and difficult to conduct.
And the second possible reason for the apparent lack of strong evidence for the efficacy of mindfulness meditation to alleviate depression, anxiety and pain, and the lack of any evidence that mindfulness can improve attention, drug dependence, eating disorders, insomnia and overall mood?
Anyone who has tried to meditate knows that it takes time and dedication. The length of training in these studies was only 30-40 hours, and most of the studies followed up patients for less than a year. It’s remarkable, in fact, that the research found any evidence of effects at all after such a short time, and considering that many patients will struggle to maintain daily practice.
Pills may remain the best option for a lot of people, not because meditation doesn’t work, but because it requires long-term commitment and time out from busy schedules. It’s so much easier to pop a pill.