As we conclude our journey through the psychological landscape shaped by testosterone, it’s clear that this hormone is far more than just a biological machismo maker. As we wrap up our whirlwind tour of testosterone’s psychological effects, it’s crucial to emphasize the importance of balance. It’s worth noting that testosterone levels can fluctuate in response to various factors, including stress, physical activity, and even relationship status. Of course, we can’t talk about testosterone without mentioning its effects on sexual behavior and libido. In the realm of social behavior, testosterone plays a fascinating role. Testosterone treatment for reasons other than possible improvement of sexual dysfunction may not be recommended. Testosterone is included in the World Health Organization's list of essential medicines, which are the most important medications needed in a basic health system. Decline of testosterone production with age has led to interest in androgen replacement therapy. Testosterone is used as a medication for the treatment of male hypogonadism, gender dysphoria, and certain types of breast cancer. In androgen-deficient men with concomitant autoimmune thyroiditis, substitution therapy with testosterone leads to a decrease in thyroid autoantibody titres and an increase in thyroid's secretory capacity (SPINA-GT). As demonstrated by a meta-analysis, substitution therapy with testosterone results in a significant reduction of inflammatory markers. In people who have undergone testosterone deprivation therapy, testosterone increases beyond the castrate level have been shown to increase the rate of spread of an existing prostate cancer. It’s important to note that the effects of testosterone on mood and emotional regulation can vary significantly between individuals. This effect could be related to testosterone’s impact on the brain regions involved in processing social and emotional information. However, the relationship between testosterone and anxiety can be complex, with both low and high levels potentially contributing to anxiety symptoms in different contexts. Some studies suggest that testosterone may have anxiolytic (anxiety-reducing) properties, potentially by modulating the brain’s response to stress. However, the relationship between testosterone and mood is not straightforward, and more research is needed to fully understand this connection. This connection has led to the exploration of testosterone replacement therapy as a potential treatment for depression in men with low testosterone levels. Psychological, social, and environmental influences all contribute to an individual’s sexual experiences and preferences. Even so, once an elite class emerges in complex societies based on differential access to resources, many of the prototypical aspects of testosterone-based primate societies emerge. Many social primates have large differences in social status. Offspring of dominant females have an easier time because their mother's high status rubs off on them, so to speak. Low-status females have trouble raising males that are big and strong enough to climb the status hierarchy and thus focus on females who are more reproductively successful. This is possible for a high-ranking female because the others defer to her in respect to access to food and shelter. It’s like a natural cognitive enhancer, helping us stay on task and filter out distractions. Testosterone also plays a role in sharpening our mental focus. Yep, you can thank testosterone for that spatial prowess. It is bound 65% to sex hormone-binding globulin (SHBG) and 33% bound weakly to albumin. The plasma protein binding of testosterone is 98.0 to 98.5%, with 1.5 to 2.0% free or unbound. The amount of testosterone synthesized is regulated by the hypothalamic–pituitary–testicular axis (Figure 2). In addition, the amount of testosterone produced by existing Leydig cells is under the control of LH, which regulates the expression of 17β-hydroxysteroid dehydrogenase. This viewpoint sees traits as having the same psychological meaning in everyone. It tends to use case studies for information gathering. "Personality is the dynamic organization within the individual of those psychophysical systems that determine his characteristics behavior and thought" (Allport, 1961, p. 28). It is primarily produced in the ovaries in women and in smaller amounts by the testes in men, as well as by the adrenal glands in both sexes. However, TRT is not a universal solution and should be approached with caution, considering the potential side effects and individual variations in response. Dimensions of sexuality are rather important in this context, but are not target of this article and covered in another part of this special edition.
