The benefits of employment on mental health might be gained from just one day’s work a week, research suggests.

Unemployment has previously been linked to poorer mental health, with experts suggesting part of the reason could be that work offers benefits including time structure, social contacts and a sense of identity.

But there was a key question left unanswered. “Nobody seemed to have said how much of it you need to get those benefits,” said Brendan Burchell, a co-author of the research from the University of Cambridge.

Now researchers say they have found a positive impact on mental health on moving from unemployment to a paid job, and that this boost is gained from working up to eight hours, or about one day, a week. There is no extra mental health benefit from working longer than this.

Writing in the journal Social Science and Medicine, Burchell and colleagues describe how they came to their conclusions by analysing responses to a UK survey conducted every year from 2009, focusing on data from more than 71,000 individuals aged 16 to 64 who gave answers for two or more years.

Among the questions, participants were asked to complete a questionnaire to provide a score for their mental health, rate their life satisfaction, and provide a host of other data, including their employment status and hours of work.

After taking into account other factors such as household income, age, whether the participant had children, and illness, the results showed that shifting from unemployment to employment reduced people’s risk of falling into the “poorest mental health” category – defined as the lowest fifth of the scores collected – by 30%. The reduction was the same regardless of whether the participant worked about one day a week or many more hours.

Burchell noted that only a small improvement to someone’s score could be enough for them to no longer be classed in the poorest mental health category.

The benefits for mental health of several hours of paid employment a week were also seen for women and men who were not working because of factors such as disability, parental leave, retirement or caring responsibilities.

Further analysis of those employed suggested that, in general, working fewer than the standard full-time hours of 36 to 40 hours a week was not linked to worse mental health or wellbeing.

However, the study has limitations, including that it does not prove that work fuels better mental health, only that they are linked, and does not take into account whether individuals undertook other activities such as voluntary work, or what jobs people were doing.

The authors say while measures such as universal basic income have been put forward as a way to tackle a future in which many jobs are expected to be done by machines, the research reveals the importance of sharing limited employment around to help safeguard mental health, and supports ideas such as shorter working weeks. The team also suggests other employment patterns, including having longer holidays, might be part of a solution.

“It is much, much better to reduce the working hours for everybody than it is to have an increase in unemployment for some people,” said Burchell.

Mike Slade, a professor of mental health recovery and social inclusion at the University of Nottingham, said: “This is a really important study demonstrating the importance of these socially valued roles like employment,” adding that the research highlighted the importance of supporting those with mental health problems who are looking to get back into work.

However, he also urged caution. “We need to avoid overly simplistic interpretations of the findings, since just reducing hours for everyone may inadvertently increase inequality in society and push more people into poverty, and forcing people who cannot work into employment ‘because it’s good for them’ can actually be very detrimental to their health,” he said.