Primates in Biomedical Research News Item
The Times, February 28, 2002
At last, the secret of what makes men grumpy
By Nigel Hawkes
Grumpy men could soon start getting the kind of knowing glances that women of
a certain age have long been used to.
It is all in their hormones, according to a scientist. When levels of the
male sex hormone testosterone begin to drop, irritation increases.
Gerald Lincoln of the Medical Research Council's Human Reproductive Sciences
Unit in Edinburgh first identified the syndrome in Soay sheep. He found that
in the autumn, the ram's testosterone soars and they rut, but in the winter it
plummets. High testosterone is supposed to mean more aggression, but it turned
out that the rams were more likely to injure themselves when testosterone was
Dr. Lincoln monitored eight rams, counting how often they struck out with
their horns. As testosterone levels fell, the rams changed from well-balanced
males who treated each other in a formal, ritualistic fashion, to nervous,
withdrawn animals who struck out irrationally.
Red deer, reindeer, mouflon and Indian elephants also show clear signs of
what he has christened irritable male syndrome, when testosterone levels fall
off at the end of their breeding seasons.
Dr. Lincoln's colleague, Richard Anderson, has found that when men who
cannot produce testosterone are taken off hormone replacement therapy they
become irritable and depressed, but their mood improves when they resume
Dr. Lincoln told New Scientist that stresses such as bereavement, divorce or
life-threatening illnesses could send testosterone levels plummeting. He says
there are few human studies on stress and testosterone, but numerous studies
on animals, including primates, show that testosterone levels fall when stress
sends corticosteroid levels up.
David Abbott, a reproductive specialist from the Wisconsin Primate
Research Center in Madison, said: "It's right on the money. Testosterone
effects have been missed. When a bloke gets grumpy and irritable researchers
try and explain it only in terms of cortisol levels and depression. They
ignore the fact testosterone levels are probably also falling."
David Handelsman, a male hormones expert a Sydney University, is not so
sure. He says that the changes in testosterone levels in normal adult men are
far smaller than the dramatic swings seen in Soay rams.
The big exception is men who undergo castration for advanced prostate
cancer, where levels fall by at least 90 per cent.
Kenn-Hun Tai, of the Peter MacCallum Cancer Institute in Melbourne, said:
"The wives notice it first. The men become more withdrawn but more emotional.
They laugh and cry more easily."
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