Testosterone in healthy men increases their brains' response to threat

August 11, 2014, Elsevier
Ball-and-stick model of the testosterone molecule, C19H28O2, as found in the crystal structure of testosterone monohydrate. Credit: Ben Mills/Wikipedia

Testosterone, a steroid hormone, is well known to contribute to aggressive behavior in males, but the neural circuits through which testosterone exerts these effects have not been clear.

Prior studies found that the administration of a single dose of influenced brain circuit function. Surprisingly, however, these studies were conducted exclusively in women.

Researchers, led by Dr. Justin Carré, sought to rectify this gap by conducting a study of the effects of testosterone on the brain's response to threat cues in healthy men.

They focused their attention on brain structures that mediate threat processing and , including the amygdala, hypothalamus, and periaqueductal gray.

The researchers recruited 16 healthy young male volunteers, who completed two test days on which they received either testosterone or placebo. On both testing days, the men first received a drug that suppressed their testosterone. This step ensured that testosterone levels were similar among all study participants. The amount of testosterone administered in this study only returned to the normal range. Subjects then completed a face-matching task while undergoing a functional magnetic resonance imaging scan.

Data analyses revealed that, compared with placebo, testosterone increased reactivity of the amygdala, hypothalamus and periaqueductal grey when viewing angry facial expressions.

"We were able to show for the first time that increasing levels of testosterone within the normal physiological range can have a profound effect on brain circuits that are involved in threat-processing and human aggression," said Carré, Assistant Professor at Nipissing University.

"Understanding testosterone effects on the brain activity patterns associated with threat and aggression may help us to better understand the 'fight or flight' response in males that may be relevant to aggression and anxiety," commented Dr. John Krystal, Editor of Biological Psychiatry.

Expanding our knowledge of exactly how testosterone affects the male is particularly important, as testosterone augmentation has become increasingly promoted and aggressively marketed as a solution to reduced virility in aging men. Further work is indeed continuing, Carré said. "Our current work is examining the extent to which a single administration of testosterone influences aggressive and competitive behavior in men."

Explore further: How much testosterone is too much for women after menopause?

More information: The article is "Testosterone Rapidly Increases Neural Reactivity to Threat in Healthy Men: A Novel Two-Step Pharmacological Challenge Paradigm" by Stefan M.M. Goetz, Lingfei Tang, Moriah E. Thomason, Michael P. Diamond, Ahmad R. Hariri, and Justin M. Carré (DOI: 10.1016/j.biopsych.2014.01.016). The article appears in Biological Psychiatry, Volume 76, Issue 4 (August 15, 2014)

Related Stories

How much testosterone is too much for women after menopause?

June 10, 2014
Testosterone supplementation for women is a hot topic. A new pharmacokinetics study of a brand of testosterone cream for women approved in Western Australia has been published online in Menopause, the journal of The North ...

Low testosterone levels may indicate worsening of disease for men with prostate cancer

May 5, 2014
For men with low-risk prostate cancer, low levels of testosterone may indicate a worsening of their disease. That's the conclusion of a new study published in BJU International. The findings may help physicians identify patients ...

Self-employed men have higher levels of testosterone, study finds

March 4, 2014
(Medical Xpress)—An abundance of the sex hormone testosterone is associated with being self-employed, a study from the University of Birmingham, University of Surrey and the University of Adelaide study has found.

Men, women in more satisfying relationships have lower testosterone

April 11, 2014
(Medical Xpress)—Many people assume that the more testosterone, the better, but a new University of Michigan study finds that might not always be the case in romantic relationships.

Testosterone replacement may help older men improve and maintain aerobic capacity

June 23, 2014
Testosterone replacement therapy may help older men who have limited mobility and low testosterone improve their aerobic capacity and lessen its decline with age, new research finds. The results were presented in a poster ...

Male health linked to testosterone exposure in womb, study finds

April 22, 2014
Men's susceptibility to serious health conditions may be influenced by low exposure to testosterone in the womb, new research suggests.

Recommended for you

Inherited IQ can increase in early childhood

January 18, 2018
When it comes to intelligence, environment and education matter – more than we think.

Modulating molecules: Study shows oxytocin helps the brain to modulate social signals

January 17, 2018
Between sights, sounds, smells and other senses, the brain is flooded with stimuli on a moment-to-moment basis. How can it sort through the flood of information to decide what is important and what can be relegated to the ...

Baby brains help infants figure it out before they try it out

January 17, 2018
Babies often amaze their parents when they seemingly learn new skills overnight—how to walk, for example. But their brains were probably prepping for those tasks long before their first steps occurred, according to researchers.

Reducing sessions of trauma-focused psychotherapy does not affect effectiveness

January 17, 2018
Posttraumatic Stress Disorder (PTSD) patients treated with as few as five sessions of trauma-focused psychotherapy find it equally effective as receiving 12 sessions.

How past intentions influence generosity toward the future

January 17, 2018
Over time, it really is the thought that counts – provided we know what that thought was, suggests new research from Duke University's Fuqua School of Business.

Tracking the impact of early abuse and neglect

January 17, 2018
Children who experience abuse and neglect early in life are more likely to have problems in social relationships and underachieve academically as adults.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.