It seems logical that people who work long hours and have a stressful job are more likely to suffer from depression, yet epidemiological studies that have investigated the links between long working hours and depression have reported inconsistent findings.

The Whitehall II prospective cohort study followed nearly 3,000 British staff from across 20 civil service departments in London. The men and women in the study (all aged 35-55) were free from depression and anxiety symptoms at the start in 1997 and were followed up until 2004.

Weekly working hours were divided into three categories:

• 35-40 hours/week
• 41-55 hours/week
• >55 hours/week

The study took into account employment status, sex, age, marital status, occupational grade, alcohol consumption, smoking and the presence of chronic disease.

Depression and anxiety symptoms were measured using the General Health Questionnaire.

Here’s what they found:

Men and women

• Compared with 35-40 hours/week, working >55 hours/week was associated with an increased risk of depression and anxiety (depressive symptoms: HR 1.66, 95% CI 1.06 to 2.61; anxiety symptoms: HR 1.74, 95% CI 1.15 to 2.61)
• Compared with 35-40 hours/week, working 41-55 hours/week was not associated with an increased risk of depression and anxiety

• Compared with 35-40 hours/week, women who worked >55 hours/week were at increased risk of depression and anxiety (depressive symptoms: HR 2.67, 95% CI 1.07 to 6.68; anxiety symptoms: HR 2.84, 95% CI 1.27 to 6.34)
• Compared with 35-40 hours/week, women who worked 41-55 hours/week were at increased risk of depression and anxiety (depressive symptoms: HR 2.15, 95% CI 1.28 to 3.60; anxiety symptoms: HR 1.69, 95% CI 1.02 to 2.81)

• In men, each 10 hour increase in the working week saw a significant increase in risk of anxiety symptoms (HR 1.19, 95% CI 1.03 to 1.38)

The authors concluded:

Working long hours is a risk factor for development of depressive and anxiety symptoms in women.

There are a number of potential weaknesses in this research that are worth highlighting:

• The study focuses on white collar civil servants and so the findings are not generalisable to the population at large
• The data relies on study participants self-reporting, so there may be inaccuracies inherent in this approach
• Other studies have used a proxy measure (such as antidepressant prescriptions) to measure the increased risk of depression

So, hard working women the world over won’t find anything too surprising in this study, but it’s good to see a high quality piece of research confirm what Dolly’s been singing for years.  Although it’s those women that work from 8am to 7pm five days a week that are probably most at risk.  I guess ‘working 8 to 7’ doesn’t scan quite as well:

Working 9 to 5
What a way to make a living
Barely getting by
Its all taking
And no giving
They just use your mind
And they never give you credit
Its enough to drive you
Crazy if you let it

Link

Virtanen M, Ferrie JE, Singh-Manoux A, Shipley MJ, Stansfeld SA, Marmot MG, Ahola K, Vahtera J, Kivimäki M. Long working hours and symptoms of anxiety and depression: a 5-year follow-up of the Whitehall II study. Psychol Med. 2011 Feb 18:1-10.