In one large study, a four-day work week with no cut in pay was followed by better mental health, less burnout and better sleep, but the study cannot prove the shorter week was the cause. Across 2,896 employees in 141 organisations in six countries, burnout, job satisfaction, mental health and physical health all improved after a six-month trial, and the authors did not see that pattern in 12 control companies. [fan-2025] This guide covers what the researchers did, what they found, what the design could not show and what you can do if your own employer is not offering one. Our overview of workplace stress covers the wider picture.
Does a four-day work week improve mental health?
On average, in this study, yes, with an important qualifier about how the study was built. Fan and colleagues studied an organisation-wide four-day week with no reduction in pay, and reported improvements in burnout, job satisfaction, mental health and physical health in the 141 organisations that took part. The pattern was not observed in 12 control companies. [fan-2025]
The qualifier is that the organisations did not simply remove a day. They went through pre-trial work reorganisation to improve efficiency and collaboration, followed by a six-month trial. [fan-2025] So the finding describes a shorter week combined with deliberate work redesign.
What did the four-day week trial find?
It found improvements across four well-being measures after the trial compared with before it. The data came from 2,896 employees across 141 organisations in Australia, Canada, Ireland, New Zealand, the UK and the USA, and the authors concluded that income-preserving four-day weeks are an effective organisational intervention for enhancing workers’ well-being. [fan-2025]
The abstract names the measures but gives no effect sizes, so this guide does not quote one. The researchers’ own description of the project says employee information came from surveys and interviews, while companies supplied administrative data, and that the team analysed changes before and after the trial. [smith-2022]
Number of organisations in the analysis, as reported in the abstract of Fan et al. (2025): 141 organisations that ran the four-day week trial and 12 control companies.
| Question | What the study reports |
|---|---|
| Who | 2,896 employees in 141 organisations across six countries |
| What changed | Shorter week, pay unchanged, plus work reorganisation beforehand |
| Trial length | Six months |
| Outcomes that improved | Burnout, job satisfaction, mental health, physical health |
| Comparison | Before and after the trial, plus 12 control companies |
| Random assignment? | Not described in the abstract |
| Data | Not yet public; the authors plan to release them through ICPSR by 2027 |
Why might fewer working days help?
The authors identified three links between the shorter week and better well-being, and they are the most useful part of the abstract. Improved self-reported work ability, reduced sleep problems and decreased fatigue each mediated the relationship, meaning the gains in well-being were statistically tied to changes in those three things. [fan-2025]
Two other findings are worth holding together. Both company-level and individual-level reductions in hours were correlated with well-being gains, and larger individual-level reductions, though not larger company-level ones, went with greater improvement. [fan-2025] In plain terms, workers who cut more of their own hours tended to gain more, and what a company announced mattered less than what each person actually worked.
The researchers added their own explanation for why output held up: companies decreased or cut activities of questionable or low value, with meetings a major target, and employees used the extra day for appointments, errands and leisure. [smith-2022] That is an interpretation from a 2022 news release about early data, not a tested result in the published abstract.
What can this study not show about the four-day week?
It cannot show that the shorter week caused the improvement, and it cannot say how much came from the shorter week as opposed to the work redesign that came with it. The abstract describes pre-trial reorganisation, a six-month trial and a before-and-after comparison with 12 control companies. It does not describe random assignment of organisations. [fan-2025]
Four more limits matter:
- The organisations opted in. The programme was offered to companies that had adopted a four-day week or were interested in doing so, with coaching provided to participants. [smith-2022] Organisations that sign up may differ from ones that do not.
- The organiser is an advocate. The programme was run by 4 Day Week Global, a non-profit established to provide a platform for supporters of the four-day week, and one of the authors served on its academic board when the 2022 release was written. [smith-2022] That is not evidence of bias in the results, but readers should know it.
- The data are not public yet. The authors say the data are not publicly available because many participating organisations are identifiable, that they plan to release them by 2027, and that analysis scripts are available through OSF. [fan-2025] Independent reanalysis has to wait.
- It is six months. The abstract reports a six-month trial, so it says nothing about what happens over years, and nothing about a four-day week with lower pay or the same hours squeezed into four days. [fan-2025]
What can you do if your employer will not offer one?
You can aim at the three things the study linked to better well-being: how able you feel to do your work, how well you sleep and how fatigued you are. That is our adaptation of the findings, not something the study tested, and it will not replicate a company-wide redesign. A realistic version is to look for low-value work you can drop, such as a recurring meeting with no decision attached, and to protect one weekday evening and one weekend block with nothing scheduled.
Is your week the problem?
Tick anything that is true for you most weeks. This is a prompt for reflection, not a test, and it produces no diagnosis.
0 of 5 ticked
Several of these together suggest workload, sleep or recovery may be part of how stressed you feel. The stress screener gives a more structured picture, and talking to your manager about specific tasks to drop is a concrete first step.
One or two of these is common. Notice whether it is a bad patch or a pattern before changing anything.
Nothing on this list applies right now. If you still feel stressed, the cause may be elsewhere.
If Sunday evening is the hard part, our guide to the Sunday scaries covers what the research on weekday mood actually shows. If the job itself is wearing you down, signs of a toxic workplace and a job that is making you depressed cover the next questions.
When to seek help
Speak to a doctor if work stress is affecting your sleep, your mood or your health, or if you have felt exhausted and hopeless for weeks, whatever your working pattern. A shorter week is not a treatment for a mental health condition. If you feel unable to keep yourself safe, contact your local emergency services or a crisis helpline.
How MyFreud can help
A shorter week is not on offer for most people, but noticing your own pattern is. Daily mood tracking in MyFreud shows how your days go across a working week, and the notepad is somewhere to log which meetings and tasks drain you next to how you slept. It does not replace a doctor.
Download MyFreud and start today: App Store or Google Play.