The Problem
The WHO estimates that depression and anxiety together account for 75,000,000 DALYs annually, making up ~5% of total DALYs. In “Measuring the Impact of Mental Illness on Quality of Life”, I argue that there is good reason to think that the system used to generate these estimates severely underestimates the impact of mental illness, and thus the true damage may be much higher. To try to get an estimate on the harms of mental health and the benefits of alieviating mental health problems, I did a preliminary cost-effectiveness analysis of Mindfulness Based Stress Reduction (MBSR).
The Intervention
MBSR is an eight week class that uses a combination of mindfulness, body awareness, and yoga to improve quality of life and perhaps physical health for a variety of conditions.
MBSR was created by Jon Kabat-Zinn at the University of Massachusetts in the 1970s, but has spread widely since then. The exact extent of this spread is hard to measure because no official registration is required to teach mindfulness and many classes and books claim to be mindfulness inspired. For the purpose of this evaluation I looked only at things that were officially MBSR or adhered very closely to the description.
Cost of MBSR
Herman, et al. (2017) estimated the marginal cost of an MBSR class participant at $150. The first three hits on google (run in an incognito browser but suspiciously near the location from which I ran the search) for MBSR listed a cost of $395-$595, $275-$425, and $350. The difference between the top of the range and the marginal cost indicates that the high end of that range probably covers all of the costs involved with MBSR (space rental and instructor time for eight weeks of classes plus one eight hour retreat) and then some, so I will use $600 as the ceiling on costs and $150 as the floor.
MBSR has an unusually high time ongoing cost (one hour per day). To model this, I included a range of DALYs as a cost, ranging from 0 (indicating no cost) to 1/24 (as if the participant were dead for that hour). It is unclear how the one hour duration was chosen and I could not find any studies on the comparative impact of different lengths of meditation; it’s quite plausible one could get the same results in less time. For the purpose of this document I used the official program, because it was the most consistently studied.
Cost Effectiveness Analysis of MBSR
Both depression and anxiety are measured with a variety of clinical surveys. To estimate impact, I assumed that the top score on each survey caused a DALY loss equal to severe depression/anxiety, as estimated by the World Health Organization, and that a drop of N percentage points led to a drop of disability weight * N. For example, a drop of 8 points on an 80 point scale of anxiety (disability weight of severe anxiety: 0.523) causes a gain of .0523 DALYs.
For a survey of papers showing potential impact, see this spreadsheet. The estimates range from 2% to 11%, clustered around 7%.
I have created a Guesstimate model to estimate the impact of MBSR. Results were quite promising. On a randomly selected guesstimate run, the average cost was $290/DALY, with a range from $43/DALY to $930/DALY. This is close to but better than Strong Mind’s $650/DALY and overlaps with estimates of antimalarial treatment ($8.15-$150/DALY). Note that the MBSR estimate may understate the impact due to systemic biases in how DALYs are calculated. However it may also overstate the impact, as medical studies tend to overstate intervention impacts for a variety of reasons.
The model makes no attempt to account for co-morbid disorders. Individuals with depression and anxiety would likely see higher benefits, since the same hour of meditation would impact both.
This model makes the rather optimistic assumption the benefits persist for life. This assumes that the participant would have been counterfactually depressed forever without treatment. In reality the average depressive episode lasts six months, and of people who have suffered at least one episode, the average lifetime number of episodes is four. If we assume the participant gets two years of benefit out of treatment the cost becomes $1200 to $14,000/DALY, with an average of $5200/DALY.
Caveats
All of the effectiveness studies cited were done on developed world citizens with only mild to moderate mental illnesses. Most were middle aged, and access to MBSR implies a minimum SES bar. It is possible that more severe depression is not amenable to MBSR, or that it is amenable and shows a larger absolute change because there is farther to improve.
I could find no studies on MBSR in the developing world, although since mindfulness meditation was originally created before there was such a thing as the developed world, there is a higher than typical chance that its usefulness will survive cultural translation.
All of the studies referenced had small sample sizes. They all show a consistent effect, but it’s possible publication bias is keeping negative studies out of view.
Official MBSR has an unusually high time cost compared to medication and therapy. The costs are high both upfront (eight weeks of classes and an all day retreat) and ongoing (one hour of meditation/day). Some patients may be able to get the benefits of MBSR with less time; others may not be able to practice at all due to the time demands.
Hello Elizabeth, thanks for writing this up. I think this is important work so please take all my points belows as friendly suggestions for improving the methodology so we can get a better answer or just clarificatory questions because I don't know what something is (I always find it quite hard to understand other people's CEA models).
Saying MBSR will have an effect for 38 years after treatment seems extremely generous. Do you have any data either way on how long the benefits of mindfulness last for? I've seen stuff saying CBT works for 5 years on depression(/anxiety) without much of a drop, but 38 years is very long.
What is 'time cost of initial work'?
What does 'negative years of life after treatment' refer to?
The effects of MBSR on deprssion/anxiety (or is it just anxiety? I haven't check the studies yet) you report are much weaker than I expected. The 7% number suggests that just 7% of the 'DALY-badness' of anxiety has been removed, suggesting it makes a dent in, rather than 'cures', the condition. Do you know what's going on here? Is MBSR partially effective (and how does this compare to CBT)? Are these perhaps studies on low anxiety people that got completed cured? Something else? I would think the effect, while it lasts, would have a much higher impact.
Time cost for continued practice seems odd to me. First, it's pretty implausible every person who went on an MBSR course would do 1 hour's practice each day (and very implausible if you assume they will do this for a next 39 years!). Second, you seem to be assuming the DALY weight of each hour meditating is 0.5, which is roughly as bad as it is to be anxious anyway, no? Surely time meditating can't be that painful. Unless you think meditation is actually unpleasant, something people suffer through to get less stressed when not meditating, I'd remove that part of the CEA. Meditation seems neutral/good IME. The appropriate counterfactual is how pleasant is meditation vs whatever they would have been doing instead with that time (e.g. watching tv?).
Your model also seems to assume that, if not for the treatment, the person wouldn't have had MBSR at all. Given the spread of mindfulness practice worldwide, I think this is better thought of as "if we fund this intervention, how much earlier will it cause 1 average person to start practising mindfulness than they otherwise would have?" If they person would have been an avid mindfulness-er 5 years later anyway, the effect is just 5 years. There's also the possible counterfactual that teaching this one person caused them to speed up the spread of mindfulness because they pass it on to their friends. And there's the possibility they would have used something else, such as CBT, to treat their depression/anxiety, anyway rather than left it untreated. Or that their depression/anxiety would have ended naturally. I'm unsure how to work through these counterfactuals, but it ought to be flagged even if you ultimately say "I'm just going to leave aside these counterfactual effects as too complicated".
Another worry comes when I ask myself "would this be a good thing for EAs to fund?" It seems anyone with access to the internet could self-teach mindfulness if they really wanted to. Hence the relevant obstacles are that people don't want to do it or aren't aware of it. I doubt there are hordes of people who know about MBSR and would do it but are lacking the funds to pay for the course themself. In the developed world, people could probably cough up $300 themselves. It seems a bit weird for EAs to be paying for the medical treatments of other people in the developed world. Suppose, instead, this is a medical treatment to be offered the depressed/anxious in the developing world. Then my concern is one of cultural barriers and that take up of mindfulness would be quite low (intuitively, this seems like a bigger problem for mindfulness than CBT).
If the true obstacles aren't money but awareness or motivation, that suggests the better things for EAs to do might be paying for public campaigns that advertise mindfulness, e.g. via Developed Media International. My concern is then neglectedness: there are(/will be) companies trying to market mindfulness to people for a profit. If this is true, EAs might want to leave this to the market to provide and do something else. I'm not quite sure how to think about this either.
These are all great comments, thank you.
The only studies I remember (and it's been a while since I did this) checked in at 18 months and still showed significant improvement. I'd be very interested if you have a source for the CBT numbers, since that seems directly applicable.
Time to attend the class.
guesstimate doesn't have a sigmoid function, so I used a constant minus a lognormal range.
All of the studies I read were on mild-to-moderate depression or anxiety, and ended with people having no-to-mild depression/anxiety on average. It wouldn't surprise me if in reality some people got very large benefits and others got none, which would make this a somewhat better intervention because people who didn't benefit could stop.
I think treating it as bad as death is a ceiling we won't reach, but I do think many people find meditation actively unpleasant, especially if they have a mood disorder, relative to doing something distracting. If meditation were more fun than watching TV we wouldn't have to justify it with long term health.
The costs of learning are so low relative to the costs of practicing they end up not making a big difference in the model.
I am surprised to hear you say that, given your emphasis on mental health, which is suffering independent of material circumstances. Given that only 40% of Americans have the savings for an unexpected $1000 bill (https://www.prnewswire.com/news-releases/63-of-americans-cant-afford-500-car-repair-or-1000-emergency-room-visit-300200097.html) , I find it quite realistic that people would benefit from others paying for care, although I expect the time to take the class and practice to be even bigger barriers.
My intuition is the opposite: CBT was developed in a very specific cultural context and seems to take as an assumption that nothing is actually wrong. Mindfulness meditation has been practiced for... long enough that getting an actual date is infeasible.
My research on media interventions was very pessimistic, even for DMI (http://effective-altruism.com/ea/1ha/mental_health_shallow_review/). This time could be different, but I think it's a very hard problem.
I think you raise a valid point that there's a vibrant market in mindfulness apps, and I'd be very curious to know how they stacked up to the formal program.