How much meditation is enough? What the trials actually used

"How long should I meditate?" is one of the first questions people ask, and one of the hardest to answer honestly. Apps suggest ten minutes. Retreats suggest ten days. Teachers say it depends. So what did the studies people cite actually ask participants to do, and what did they get for it?

What the eight-week programs ask for

Much of the clinical research on meditation uses two programs: Mindfulness-Based Stress Reduction (MBSR), developed by Jon Kabat-Zinn, and Mindfulness-Based Cognitive Therapy (MBCT), which adapts it for people with recurrent depression. Both run for eight weeks, with a weekly group class of a couple of hours, and both assign daily home practice: guided body scans, sitting meditation and mindful movement, typically around 45 minutes a day, six days a week.

That's a lot. So in 2017, Christine Parsons, Willem Kuyken and colleagues asked what participants actually did. Pooling 43 studies with 1,427 participants, they found people completed about 64% of the assigned home practice: roughly 30 minutes a day, six days a week.

What that practice bought

The most-cited summary of the evidence is a 2014 systematic review and meta-analysis in JAMA Internal Medicine led by Madhav Goyal at Johns Hopkins. From nearly 19,000 citations, the team kept 47 randomized trials with 3,515 participants, all comparing a meditation program with a control group.

Anxiety

Moderate evidence of improvement. Effect size about 0.38 at eight weeks, 0.22 at three to six months.

Depression

Moderate evidence. Effect size about 0.30 at eight weeks, 0.23 at three to six months.

Pain

Moderate evidence. Effect size about 0.33.

Stress / distress, quality of life

Low evidence of improvement.

Compared with active treatments

No evidence that meditation programs were better than drugs, exercise or other behavioral therapies.

An effect size around 0.3 is usually described as small to moderate. It's a real, measurable change on average, comparable to what other helpful interventions achieve, but not a transformation for everyone. The authors' own conclusion was that meditation programs can produce small to moderate reductions in several dimensions of psychological stress.

Is more always better?

Not clearly. In 2020, Sarah Strohmaier analyzed 203 randomized trials of mindfulness-based programs (15,971 participants) to see whether bigger doses, measured by contact hours, program length or home practice, predicted bigger benefits. For depression, anxiety and stress, she found no evidence that larger doses were more helpful than smaller ones. More contact and more actual practice did predict larger increases in self-reported mindfulness.

At the short end, a small randomized trial by Julia Basso, Wendy Suzuki and colleagues (2019) gave people with no meditation experience a 13-minute guided meditation every day for eight weeks, compared with a group who listened to a podcast for the same time. After eight weeks, but not after four, the meditation group showed lower negative mood and anxiety and better attention and memory on lab tests. A small sample, but a useful hint: modest daily practice can show effects, and it may take more than a month.

What this means for your practice

• Pick a dose you can keep. The trials' 45 minutes became 30 in real life. For most people, 10 to 20 minutes a day that actually happens beats a target that quietly collapses.
• Think in eight-week blocks. Most programs run eight weeks, and in the short trial above, effects showed at eight weeks but not four. Give a new routine that long before judging it.
• Don't chase minutes. The evidence that more is better is weak. Consistency and attention during the session are better bets than a longer timer.
• Keep expectations honest. Small-to-moderate average effects mean some weeks you'll feel a lot, and some weeks very little. Both are normal.