New UK research has found that women who work long hours may have a higher risk of depression, and working weekends may up the risk for both men and women.

Carried out by researchers at University College London, the Department of Research and Policy at Age UK, and Queen Mary University of London, the new study looked at data on 11,215 men and 12,188 women, which included occupational information and depressive symptoms as measured by a validated general health questionnaire.

The researchers also took into account several potentially influential factors including age, marital status, whether participants had children, their wage and how satisfied they were with it, long-term health conditions, and qualifications.

A standard working week of 35 to 40 hours was used as a reference for categorising working hours into less than 35 hours a week, 41 to 55 hours a week, defined as long working hours, and 55 hours a week or more, defined as extra-long working hours.

The findings, published online in the Journal of Epidemiology & Community Health, showed that women who worked extra-long hours of 55 or more hours a week and/or who worked most or every weekend had the worst mental health of all the participants, with significantly more depressive symptoms than women who worked standard hours.

For men, working less or more hours than the standard working week had no effect on the number of depressive symptoms.