August 05, 2007
Night Shift Work Lowers Serotonin Neurotransmitter

If you are prone to depression don't work the late night shift.

WESTCHESTER, Ill. -- People who work rotating shifts have significantly lower levels of serotonin, a hormone and neurotransmitter in the central nervous system believed to play an important role in the regulation of sleep, according to a study published in the August 1st issue of the journal SLEEP.

Heard of anti-depressant drugs like Prozac, Celexa, Lexapro, Zoloft, or Paxil? They are all selective serotonin reuptake inhibitors (SSRIs). They work by preventing neurons from pulling serotonin back onto the internal side of neural cell membranes. That leaves more serotonin to bind to receptors which boosts certain types of neural signalling which somehow lifts people out of depression. But if you do something that lowers the amount of serotonin available (and working the night shift does this) then you are going to be more prone to depression.

Night shift workers are probably not asking for enough additional compensation to make it worth the effect on their bodies.

The study, authored by Carlos J. Pirola, PhD, of the Universidad de Buenos Aires, Argentina, focused on 683 men of self-reported European ancestry, in which 437 day workers were compared with 246 rotating shift workers. Day and night work periods started at 6 a.m. and 6 p.m. respectively. None of the subjects interchanged their job schedule.

The results showed that serotonin content differed greatly between day workers and rotating shift workers, with levels of serotonin significantly higher in day workers.

“These findings may be important not only to understand the mechanisms related to the circadian rhythm desynchronization imposed by the rotating shift work regime, but also to target truly effective therapeutic strategies that may ameliorate the associated comorbidities and behavioral problems in rotating shift workers,” said Pirola.

In addition to sleep problems, low levels of serotonin are also associated with other conditions such as anger, depression and anxiety.

What would be interesting follow-up experiments: Can high intensity lights, melatonin, or some other treatment or style of living allow people to work late shifts without lowered serotonin? Also, is some fraction of the populace able to do late shift work without getting lowered levels of serotonin?

Share |      Randall Parker, 2007 August 05 06:23 PM  Brain Sleep


Comments
Nancy Lebovitz said at August 6, 2007 3:38 AM:

It looks like the research is on rotating shifts, not being on a night shift for an extended period.

Curious said at August 7, 2007 1:53 PM:

Why not just do 5-htp? In fact i know someone doing shift and i think i'll suggest it.

ian said at August 8, 2007 9:43 PM:

I second the 5-HTP recommendation. The serotonin affecting drugs you mention are such crude tools with many unwanted side effects. I would strongly recommend 5-HTP supplementation for almost anyone who would like to affect their serotonin levels.

I find limited use of melatonin effective for regaining control of your sleep cycle (or, at least controlling when you actually become unconscious). Being a radical night owl myself, the ability to determine within a short span when you will fall asleep is such a liberating experience (I've never desired to use traditional sleeping pills). Melatonin can, however, cause you to sleep-in and/or feel groggy. As well, varying degrees of dependence can occur. Melatonin used responsibly, preferably in small doses, can be a very positive addition to your diet.

paul said at April 28, 2009 7:09 AM:

HI, i work night and i am having trouble with anger depresion anxiety, should my employer be helping me in some way,? thanks

Tom said at December 20, 2009 6:40 PM:

Yeah, I know I work the night shifts as well. The best solution is to transition out of your current career path if it can involve extended periods of night shifts. I work in the food industry where 3rd shift is always a reality. Depression follows you every where; you say mean things that you do not mean. Personally, my jealously of those who only have to work 1st shift all of the time in the company has spilled out of my mouth causing disciplinary actions to be taken against me.

If you have a wife and kids, I am sorry it will be hard to change. But if you're single leave as soon as you can. Fight everyday to break into a profession where night shift does not happen. I am saving every penny I can to get out of 3rd shift for the rest of my life. I will not marry and knock anyone up until I accomplish my goal. I am too depressed to go on like this.

summer27819 said at December 31, 2009 4:13 AM:

I work 1-10 p.m. every night and every other Saturday 8;00 a.m.- 1:00p.m. for the last year. It has about killed me. It has drained my soul, my well being, my social life; I am single and I too look @ people on a "normal" schedule and feel envious. I can't find a boyfriend who even wants to put up w/my hours or if I did, OI am sooo drained, all I want o do is sleep. My interest in things is gone...and I work @ a University. I have looked dilligently for anothr position but unemployment is soo high in KY. My schedule ended one r'ship ONE yr ago...and it's been that long since my last r'ship. Honestly..when I am off, all I want to do is sleep b/c my body is not in a normal sleeping rhythem. During breaks (for 2 weeks) my hours change from 10-7p.m. 11 -8 p.m. and 8-5 p.m. and then it's backl to the 1-10 p.m and 2-10 p.m. and every other Saturday 1/2 day. HELP!

Tina Moore said at April 27, 2010 6:16 AM:

I have a son that started a night shift job for the first time in his life. He took this job to support his new family. Throughout his life he has fought depression, but got better with antidepression medicine and years of prayer. On the second night of his new job, he noticed he began to feel depressed and thought he just was missing his family. After the third and forth night he was beside himself and was unable to cope with the familiar thoughts that ran through his mind. He did the unthinkable and called his supervisor to explain that he was unable to handle the job. He knew through the years of fighting this dreaded sickness, he would not be able to cope. As a mother, I was explaining that this could have been contributed to not having enough sunlight and serotonin levels falling. My son feels he failed everyone, but his worst fear is what he knows depression can do to a person. He has since then got a day time job and is doing much better.

Tina said at April 29, 2010 8:41 PM:

I have a son that started a night shift job for the first time in his life. He took this job to support his new family. Throughout his life he has fought depression, but got better with antidepression medicine and years of prayer. On the second night of his new job, he noticed he began to feel depressed and thought he just was missing his family. After the third and forth night he was beside himself and was unable to cope with the familiar thoughts that ran through his mind. He did the unthinkable and called his supervisor to explain that he was unable to handle the job. He knew through the years of fighting this dreaded sickness, he would not be able to cope. As a mother, I was explaining that this could have been contributed to not having enough sunlight and serotonin levels falling. My son feels he failed everyone, but his worst fear is what he knows depression can do to a person. He has since then got a day time job and is doing much better.

Vladimir said at November 28, 2010 8:14 AM:

Tina, your son did the best thing he could. He's really lucky at discovering that just at the beggining of his contract. For me it took around 7 years. Had suspiciouns one year ago, It really improved by starting a good vegetables diet and excercise but it becomes worse with age. By now I am feeling if I can do things better when drunk that after a 12 hours night shift. For better luck, I left my job and in 1 month time will be coming back to normal human life. Everything is going to be OK. A new beginning.

Kyzer said at December 24, 2011 9:07 PM:

This appears to be correlation, not causation. Lower serotonin levels can contribute to insomnia and being a "night owl", and individuals with insomnia or who stay up later are obviously more likely to be night shift or rotating shift workers. I'm not saying that night shift wouldn't lower serotonin, im just saying this is a cor relational study.

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