Inkling has an interesting article on the effect of stress on the menstrual cycle that investigates the received wisdom that stress can prevent periods.
It turns out the scientific studies have found no conclusive answer as they’ve returned mixed results, but this may be because they don’t adequately distinguish between physical stress and psychological stress.
A range of physical health problems are known to halt menstruation. Malnutrition is a common example and this is why women with anorexia often don’t have periods.
Of course, physical and psychological stress go hand in hand, but one study that looked at healthy young women under a great deal of psychological stress, but no major physical health problems, found no alteration in the menstrual cycle.
So Ellison examined female juniors at Harvard who were preparing for the MCAT [Medical College Admission Test] and compared their anxiety levels (and ovulation schedules) to women who were not preparing for the MCAT. In order to make sure there were no other factors at play, all the women were otherwise physically healthy, were not using any oral contraceptive pill that would change hormone levels, and all reported normal ovulation…
But despite the significant increase in stress, there was no change in ovulation or periods in either group. No matter how stressed these students were about the upcoming exam, they continued to have a visit from Aunt Flow right on schedule. This was even the case during the final days and weeks leading up to the MCAT exam, when the subjects described intense stress levels that only Harvard pre-meds can sustain. The study was published in the December 2007 issue of the American Journal of Physical Anthropology.
There’s more on the effects of stress on menstruation in the article.
Link to Inkling article ‘Of Stress and Periods’.
Mind Hacks 
I clicked on this article expecting it to say that stress can stop menstruation, since it happened to me. I was under a lot of stress from different places (work, school, and emotional stress) and my period stopped for about nine months in 2004-2005. I started on the pill in 2006, and in early 2007 I was under a lot of emotional and work stress, and it managed to make me a few days late despite the pill.
Of course, I am the type that does not handle stress well. In early 2007, when I was late, stress also made me nauseas for a month and a half. Extreme stress effects me very severely. It makes me wonder if maybe the women in the study are just better adjusted to extreme stress, so it doesn’t effect them physically like it does other people.
In the past week I was going through a lot of stress (nothing else changed: same exercise and same food, just psychological stress changed) and it made me my stomach queesy.
I think it also is a relative stress since my life in the past months has been very relaxed & calm, and then stress for the past week, and it made my menstruation only a few drops, whereas usually it flows heavily. So i see a definite relation in me, maybe the students are just always ‘stressed’ doing their studies, so it’s not such a big change of stress levels.
Well I had just finished my last period back in Feb about 15th, since the earthquake that has destroyed most of our city,(Christchurch NZ) and disrupted our lives I have not had one since.
Nothing, gone finished! It’s late April now, I still get hormonal feelings like it is about to come and it just doesn’t, I am not pregnant, and I have had scans that say all is normal! No one seems to have an answer for me, which stresses me out more.
To syntheticjesso: Maybe your extreme reaction to stress translates into physical effects for you. It sure sounds like it, with a month and a half of queasy stomach! Maybe it caused you to miss out on a balanced diet, slow down exercise, and whatnot. If stress makes you physically ill, then it would put you into the physiological group, which would be right in line with the research.
Distinguishing between psychological and physical stress seems bit vague. I mean can you have physical stress without the psychological one? And if not, then phycsical stress is just a result of psychological stress that the mind/body could not handle. My ex thought she had become pregnant when we broke up, since her perioids were two weeks late. Ends up it was just stress and apparently has happened to her also before.
I had a skyrocketing stress level which lead to an anxiety attack in which i had never experienced before.
However,i have never missed a period or been on any pill an my period was delayed as i can recall it was delayed for two weeks!!!!
m also facing some problems in periods due to stress…as it was regular before my stress begin to affect me…my periods were heavy n regular…but now they have become so light…n irregular..
I am an under an extreme amount of stress. I am very depressed and anxious and do not sleep without medication. I took some time off of school and now I am concerned about my future even though I know that I will start again in the Fall. I live in a forgein country and never see my family. My marriage is on the rocks and I have a boyfriend. That’s right, a boyfriend AND a husband. Lately the stress of having these two relationship is killing me. I know one has to go. Either I ditch the guy I love or the father of my only child. Yeah. I’d say that was a lot of stress and YEAH my periods have stopped. A study of healthy college students?! Are you serious? School is stessful, but not extraordinarily so. Of course they’re still getting there periods. Are they serious with this shit? So girls reading this will think there is something seriously wrong with their bodies or that they may be pregnant when really they are just stressed out by some serious real life problems! AHURL!
i have been experiencing frequent stops and delays in my period lately and i thought it was as a result of the emotional and physical stress i was going through but now, am even more confused because if not stress, what could be causing the irregular menstrual cycle?
okay i like the fact that their is other people with the school stress factor every day life is stress my periods have been different for a wile iv taken at home test all negitive so its not anything to do with that. my preiods very from heavy to light even stoping for a day and a half at times and i want to know facts why is this going on and how can i stop freaking out about it i have alot of stress every day sometimes way more than others and it has nothing to do with any school test.
hi, i am a doctor and i have gone through a lot of stressed exam times. My menstruation never disturbed before or during my exams. They delayed when i failed in the exam and was under a lot of stress + depression. They should check if the menstruation cycle was still regular for all these girls after the result of MCAT. And yeah, i also get delayed and scanty periods when i am stressed and depressed about major life events like break ups and deciding future husbands ect :p . so my conclution is, when you are stressed and also suffering from a bit depression, your menstrual cycle become irregular. It may not be true for everyone though, many people dont get affected by stress physically as much as some do.