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Question #46080 posted on 07/04/2008 3:01 a.m.

Dear 100 Hour Board,

In response to Board Question #45985 about hormonal cycles in men, we actually discussed this in my Behavioral Neurobiology (Psych 381) class. I wish I still had the lecture slides on my computer, because within it there were a couple references to scholarly peer-reviewed articles confirming the myth.

If I'm remembering correctly, the crazy hormone cycles of men are due to a similar hypothalamus (and I think maybe amygdala) structure that is not unlike the hypothalamus structure in women. Structural similarity leads to functional similarity, I guess. Given the structure/function of the hypothalamus (which is the "master regulator" of the human body and all things hormonal), men who have the smaller (I think) hypothalamus (like women) tend to have monthly mood swings like women. This is very common in homosexual men.

Again, I'm sorry that I don't remember the sources. I know that they do exist, though.

--The Junior Neurologist

A: Dear Junior Neurologist,

I too remember some research about male hormonal cycles, but I was too busy to really answer the question at the time it came in to the inbox. My sex and gender book has a snippet about male hormonal cycles. I'll type it up here:
Both men and women experience daily rhythms on physiological dimensions such as body temperature, blood sugar levels, and sleeping/waking. Such cycles can affect alertness, mood, and performance (Monk, Moline, Fookson, & Peetz, 1989). There may also be seasonal cycles. One Italian study of suicide records over 12 years identified different seasonal variation cycles for women and men (Micciolo, Zimmerman-Tansella, WIlliams, & Tansella, 1989). Estelle Ramey (1972) reviewed limited evidence that men show cyclic patterns of their moods and physical symptoms, just as there are large individual differences among women. McFarlene and Williams (1994), who found evidence for mood cycles among both women and men, also found that there was a great deal of individual variability in both sexes. Furthermore, mood cycles did no necessarily conform to the menstrual cycle of women or to such obvious social markers as weekends for either men or women. Thus, the female menstrual cycle may be only one of a number of human biological cycles that have a potential impact on mood or behavior.

Ramey (1972) cites one study, carried out in Denmark, in which fluctuations of testosterone levels in male urine were followed for 16 years. A 30-day rhythmic cycle of hormone levels was found. Another study cited by Ramey involved male managers and workers in a factory. The investigator in this case measured not hormones but mood and found an emotional cycle of 4 to 6 weeks in which low periods were characterized by apathy, indifference, and overrations to minor problems and high periods by feelings of well-being, energy, lower body weight, and decreased need for sleep. A study by Doering, Brodie, Kraemer, Becker, and Hamburg (1974) measured both hormonal fluctuations and moods in 20 men for 2 months and found evidence supporting a link between the two. They reported a significant positive correlation between levels of self-reported depression and concentration of plasma testosterone in the blood. Their data, however, showed only weak evidence for rhythmic changes in testosterone levels.
So, just a reminder: all research is fallible, and a lot of the research that doesn't find anything doesn't get published. So it looks like there are some emotional cycles in men, but we don't really know how or why. I'm skeptical of your report of the research, mainly because most of the research linking male homosexual brains to female brains relies on sexual stimuli (although if you're interested in the subject, this is a science blog post that gives a nice overview).

-The Supershrink