Working Long Hours Linked to Mental Decline

In a recent study, working long hours was associated with decreased cognitive function in middle-aged adults.

The study examined 2,214 middle-aged British civil servants who were working full-time. The researchers performed various tests to measure the participants' cognitive function at the time of study enrollment (1997-1999) and again at follow up (2002-2004).

According to the authors, working more than 55 hours a week was linked with poorer mental skills, including impaired short-term memory and recall, compared to those who worked a standard 40 hours. Individuals who worked the most hours experienced the greatest decline in cognitive function.

These results were similar after adjusting for potential confounding factors, including age, gender, marital status, education, occupation, income, physical diseases, psychosocial factors, sleep disturbances and health-risk behaviors.

In addition, participants who worked overtime slept fewer hours, reported more symptoms of depression and drank more alcohol than those who worked just 40 hours.

The potential mechanism for these negative effects remains unknown. It is also unclear if the effects may be long-term. Additional research is warranted in this area.

For more information about cognitive decline, please visit Natural Standard's Medical Conditions database.

Comments

[Chris]

This study is somewhat of a no-brainer. Of course working longer hours will produce mental decline. It can also produce other problems in adults, such as a sedentary lifestyle, back pains, carpel tunnel, depression and stress. Stress, causing an inflammatory reaction and increases in body cortisol, has been linked to weight gain, sleep deprivation and a myriad of other diseases. Humans are not physiologically made to sit in one position for more than 40 hours a week. What I think would be a really interesting study would be an assessment of which careers present the greatest amounts of mental decline. It would be interesting to see if a job that requires more physical stress opposed to mental stress would produce the same results.

[emily bigelow]

Not surprising. How could anyone working 55 hours a week avoid burnout, which inevitably leads to poor performance? If you're working this much, chances are you're also neglecting your diet and not getting adequate exercise or devoting enough time to rejuvenating mental health practices such as meditation, tai chi and yoga. Sure enough, another study bears this out. A 2009 Spanish study of men who worked similar hours (51-60 hours a week) linked these men to poor mental health status, hypertension, job dissatisfaction, smoking shortage of sleep and no leisure-time physical activity.

[tanya]

I agree with the comments above. Working more than 55 hours weekly is obviously not good for anyone. Stress can be blamed for this decline in mental capacity, and we all know that stress has a higher link to other problems such as insomnia, depression, etc.

Another reason to have a balance between work and social life!

[Helen]

As someone who's forced to work more than 55 hours/week due to the economy (my husband lost his job and isn't eligible for unemployment, and I've had to pick up freelance work on top of my FT job just to pay the bills -- forget about going out anywhere), I agree with ALL of the above comments. I'm exhausted; I definitely don't get enough exercise, and the little free time I have left is spent sleeping. No wonder my mind is mush. Ironically, my day job is spent writing about programs that promote health at work (exercise, good nutrition, etc).

[Adele]

I personally know a medical specialist who works approximately 15 hours per day (75 hours per week) and has been doing this for at least 20 years. One day per week is dedicated to surgery, where he’s involved in some mega-surgeries that can last 6-8 hours. How can anyone stay focused for that long?? I’m especially interested in how this type of research would relate to younger medical interns who work 80+ hrs. per week, over different shifts.

[Mary]

After reading the title, I wonder why someone would even come up with a study on such a topic. This is such a no brainer! Everyone knows that if a person puts most of their time to work, then everything is going to be affected to some degree (ie: stress out easily, physical/mental health will be affected, lifestyle, relationships outside of work, ect.). Why did someone even fund this study?

[AJ]

This study was a waste of money and resources!

[Max]

I agree with several comments above. This study seems a little bit redundant. There have been lots of news stories and research about a healthy balance between work and social life. Of course there would be stress and decreased mental capacity of someone who works over 60 hours a week. With that much workload, there would be no time for anything else (exercise, relaxing, etc.) and obviously, that would lead to a whole string of health problems associated with high stress level.

[SP]

I agree with the fact that working long hours may negatively impact a person’s health. Some research suggests that sleep deprivation may result in endocrine and metabolic changes in the body that imitate the telltale signs of aging and can exacerbate various health disorders. These include: diabetes, hypertension and memory loss. I also came across a study from The Journal of Neurochemistry, which suggests that long-term sleep deprivation alters gene expression in the brain.The study, however, was conducted using rats.

[Elizabeth Nagle Griffin]

The correlation between cognitive function and sleep debt is presented in The Promise of Sleep, by Michael Dement, MD. The proper requirements for sleep are often overlooked in our society and amongst many in the medical community. A revealing read for anyone wanting to know more on the subject as presented by a pioneer researcher on the subject.

[Mike]

I wonder what percentage of the population works more that 55 hours per week and if there have been any changes in those numbers recently. I tied to search for some statistics but couldn’t find any data. It would be interesting to evaluate how the economy affects a person’s health.

[Brian]

Working long hours can lead to sleep deprivation, and sleep is very important for good mental function. Many studies that I read suggest that six to eight hours of sleep per night is needed to maintain one's health and to stay alert and well rested. An interesting point that I came across is that both too much and too little sleep is detrimental. Several studies indicated that people who slept less that four hours or more than eight hours per night showed higher death rates than people who slept six to seven hours per night.

[jaq p]

I’m sorry, but if you’re working for the government and you can’t get all of your non-work done in 40 hours, that’s an obvious sign of mental decline.

[Trevor Fields]

The potential mechanism of this is most likely exhaustion and lack of sleep. You can only physically and mentally do the same thing for so long before your body and mind simply shut down. It would be interesting to see how many of the patients studied performed job duties that required little or no mental engagement. Once you perform a task for a lengthy consecutive amount of time it becomes a “brainless” activity requiring no stimulation. This second-nature functioning lacks the input that we need as humans to stay active, alert and oriented to what reality is and function cognitively on a normal level.

Sleep deprivation and depression are also commonplace in overworked employees, as life becomes nothing more than a series of short breaks in between the repetitive actions of monotonous tasks. Unfortunately, with most job's in today’s economy, supporting a family requires a people to push themselves to the breaking point if they wish to provide their families with everything they can.

[Eugene]

This article raises some interesting questions about the internal factors of the study. I wish I knew if they followed each patient throughout the study, or did they just look at the bottom line independent of the individual patient? Also, what do they consider middle age: is it 40-60yo or is it 35-54yo, as reported by the US Census? Other studies have shown that after the age of 27 there is a decline in the amount of information a person can learn per day, but is the REAL reason for the cognitive decline associated with working more than 55 hours, or is it what you do after work?

I looked up what a British civil servant does, and it was pretty labor intensive in terms of mental strain (They work in politics…that would reduce anyone's cognitive function). How much external validity does this study have, because maybe these results don’t apply to other professions? When most medical profession do their residencies, they have to work more than 55 hours, but does this study mean that they aren’t "all there" when your life hangs in the balance? It may seem like a no brainer that working 55+ hours would decrease mental acuity, but can we really apply the finding’s from this study to other professions…I say NO.

[Riley]

I found this news brief about long hours and mental decline very interesting. Many people pride themselves on working a lot, and although it may be productive for the employer in the short-term, it is possibly detrimental for the employee in the long run. Spending more time at work doing the same thing all day probably leaves less time for more stimulating activities. This may mean less activity for the brain, and therefore, impaired mental function.