According to Jed Diamond, PhD, who wrote "The Irritable Male Syndrome ", men go through testosterone changes daily, monthly, and seasonally. Although most men deny their own form of a period, changes in their testosterone level affect them more than they think.
Irritable Male Syndrome is: “... a state of hypersensitivity, frustration, anxiety, and anger that occurs in males and is associated with biochemical changes, hormonal fluctuations, stress, and loss of male identity...”.
As men’s testosterone level drops, so do men’s moods. This hormonal change has a monthly cycle and Diamond says men can actually track it much like women can.
Men experience depression and aggression as their testosterone level declines. Although men’s testosterone level drops daily, monthly, and seasonally, the daily changes are not enough to really notice. Men's cycles don't sync with each others', though, like women's do.
But if you notice the men in your life are more “manly” toward the end of the year, it’s because male testosterone level is highest in November.
Luckily for guys, though, they can try to reduce the effects of IMS. The testosterone level in a guy is actually related to stress and weight. But the more stress in a man’s life, the more his testosterone level will drop.
** Men also go through male menopause, called andropause. This is common for men between ages 40-55.