eileen

SOURCE: orlandosentinel.com/features/lifestyle/orl-birthmonth07aug07,0,1055900.story
OrlandoSentinel.com

MIND & BODY

Born under a bad sign? Maybe

There's evidence that the time of year you are born affects your mental health.

Alison Motluk
New Scientist
August 7, 2007

The star you were born under influences the person you become.

This is not something you expect to hear from scientists but, incredibly, it seems to be true. There's firm evidence that the time of year you are born affects not just your personality, but also your health, specifically your chances of developing serious mental illness.

But don't expect to find clues in your horoscopes. The star in question is the star we were all born under -- the sun.

Being born at certain times of year gives a small but significantly increased risk of problems such as depression, schizophreniaand anorexia nervosa. The question is no longer if the seasons affect mental health, but how. Pinning this down could yield vital clues on how to intervene to prevent mental illness.

The effect was first noticed as far back as 1929, when Swiss psychologist Moritz Tramer reported that people born in late winter were more likely to develop schizophrenia.

We now know that for people born in the Northern Hemisphere in February, March and April, the risk of developing schizophrenia is between 5 percent and 10 percent greater than for those born at other times of the year.

Season of birth seems to be linked to other conditions, too. People with anorexia in the Northern Hemisphere are 13 percent more likely to have been born between April and June than in other months.

That doesn't necessarily mean that it's best to be born later in the year, however. Autumn birthdays are associated with an 8 percent increase in the likelihood of suffering panic attacks, for example, and a small but significant increase in alcoholism in men.

Finding out just how the changing seasons change the risk of certain psychiatric conditions is proving a daunting task for epidemiologists.

Until recently, the leading hypothesis on why winter and spring births increase the risk of both schizophrenia and anorexia centered on the health of a mother during pregnancy.

But more recent explanations have concentrated on the more direct effects of the seasons on the mother: how much sunshine a pregnant woman is exposed to, for example, or the effects of temperature.

The hormone melatonin, which regulates the sleep-wake cycle and is suppressed by sunshine, could play a role during gestation or early life, says Emad Salib, a British consultant psychiatrist. For example, one study found that people born in April, May and June were 17 percent more likely to commit suicide than those born in other months.

Salib reasons that as people born in April, May and June were conceived in July, August and September, high melatonin levels during crucial months of development could prompt changes in the brain, and then stimulate the act of suicide later in life.

Another way sunlight influences the body is by stimulating production of vitamin D, which fetuses need for brain development. Trouble is, in northern latitudes, there isn't enough in the winter.

In London, for example, it's hopeless, says mental-health researcher John McGrath. "You just can't make vitamin D in winter even if you lie naked all day."

McGrath suspects vitamin D deficiency might link birth date to an elevated risk of schizophrenia. Working with neuroscientist Darryl Eyles, he has established that the brains of rats deprived of vitamin D during gestation have abnormally large lateral ventricles. People with schizophrenia also have enlarged lateral ventricles.

The link between vitamin D deficiency and neurodevelopmental abnormalities is a "done deal," says McGrath, at least in rats. Does that mean the same applies to humans? "We're still working on that," he says.

Whether or not this simple explanation underlies any or all of the seasonal effects in mental health, the ultimate goal is to pin down the molecular mechanisms underlying these seasonal trends and, potentially, to fix them.

Researchers studying the season-of-birth effect do not, however, see their work as a predictive tool, and don't want to scare would-be mothers into altering their family planning.

The reassuring fact is that most winter babies escape schizophrenia, and spring babies by and large do not grow up with eating disorders. What we can hope for is that we might some day understand the biological basis for seasonal blips in the incidence of mental disorder.

And if we do that, we might then be able to fix it

Gidget

Must be true, I read the same thing in my local paper this morning!:)

__________________

eileen

Gidget I was born in September! No wonder I'm so healthy. lol

tnannie

Very interesting article Eileen.....wasn't too thrilled to see that I fit into the higher risk catagory for suicide, but I suppose it could be wrong....the anorexia part of it sure as heck skipped over me....LOL!

Gidget

Moi aussi! But I am not healty!

__________________

eileen

I've read in Alaska they aren't vit d difficeint because they eat a lot of omega oil from the fish there. You still factor in diet.... so there's hope for you tnannie. lol :)

Cali's Finest

Where does OCD come in? :)