Testosterone is more than just a sex hormone; it is a chemical that is vital for proper brain health. That is why understanding the connection between low testosterone, and the brain is crucial if you are experiencing any symptoms of cognitive or emotional decline.
Not only do you need testosterone each day to support your normal functions, but its neuroprotective nature can also help reduce the risks of stroke, Parkinson’s disease, Alzheimer’s disease, and other neurological conditions.
How does low testosterone affect the brain, and who is at risk?
As you will see in this comprehensive review, low testosterone has multiple effects on the brain. Testosterone helps to regulate emotions, endorphins, cognitive functions, memory, and even the plaque formations found in the brains of people with Alzheimer’s disease.
As we look at the effects of low testosterone on the brain, it is essential to remember that both men and women need testosterone. It is not just a male-only hormone. Aside from brain functions, everyone needs testosterone to maintain strong bones and muscles, libido, glucose and insulin regulation, and metabolic functions. Testosterone is a “whole-body” hormone that is vital for proper health and well-being.
In this report, we will cover the following topics:
- The direct impact of testosterone on the brain
- How low testosterone affects brain functions
- The influence of brain injuries, tumors, and medical treatments on testosterone levels
- What testosterone therapy can do for the brain
Testosterone is crucial for proper brain functions as well as emotional well-being.
Effects of testosterone on Brain
Testosterone exerts multiple effects on the brain, both directly, and later indirectly through its conversion into dihydrotestosterone (DHT) and estradiol (estrogen). DHT metabolites exert antidepressant and pro-cognitive effects on the brain. Estrogens aid verbal memory, cognitive functions, and emotional well-being.
In addition to the production of testosterone by the testes and ovaries, the adrenal cortex also supplies the body with some of its testosterone. However, the brain is actively involved in the biosynthesis of testosterone, which begins with the hypothalamus stimulating the pituitary gland to secrete hormones that lead to testosterone production. Because much of the body’s testosterone production takes place during sleep, testosterone levels are highest in the morning. That is also why many people report being at their cognitive best early in the day. As the day progresses, testosterone levels decline.
One of the reasons that there is a connection between afternoon mental fog and low testosterone and the brain responses is that when there is already a deficit in testosterone levels, the natural decline that occurs as the day progresses makes it that much worse in the afternoon and evening hours. Individuals who can get in a midday workout can increase daytime production of testosterone, which can help support cognitive functions.
Testosterone exhibits variances in the brain according to gender. Whereas many hormones function the same in males and females, testosterone has specific differences. One area of the brain where differences are found is the amygdala, where males experience a preference for VSS – visual sexual stimuli. Women prefer greater variety in stimuli. Both the amygdala and hippocampus are affected by testosterone.
Here are some of the ways that testosterone affects the brain:
- Regulation of stress responses, inhibiting the activity of the hypothalamic-pituitary-adrenal (HPA) axis, which responds to stress through the secretion of stress hormones such as cortisol. Testosterone, along with growth hormone (GH), oppose the actions of cortisol. When cortisol levels increase, testosterone and GH decrease and vice versa.
- Cortical thickness is different between women and men, which accounts for differences between male and female cognitive functions throughout life.
- Higher testosterone levels assist visual-spatial skills, which accounts for women with PCOS (polycystic ovarian syndrome) doing better with those tasks.
- Sexual behavior is regulated by androgen receptors in the brain. That is why low libido is a common symptom of testosterone deficiency in males and females.
- Androgen hormones such as testosterone exert a neuroprotective effect on the brain by altering the morphology, axonal regeneration, and survival of motor neurons.
- Brain responses to falling in love alter testosterone levels – they increase in females but decrease in males.
Low testosterone effects on the brain can impact these actions.
Testosterone acts on the brain both directly and indirectly through responses of DHT and estradiol.
Low Testosterone and Cognitive Impairment
Testosterone decline influences a variety of cognitive functions. With age comes multiple changes:
- Loss of memory
- Brain fog
- Poor concentration
- Mood changes
- Impaired learning
There is a connection between low testosterone and brain fog, emotional state, and memory. Spatial cognitive ability is an area of considerable research as men and women typically respond differently during early adulthood. Men perform better in this area than women – often linked to higher testosterone levels. However, with age, men experience a decline in this function.
For women, better verbal memory is thought to be connected to their lower testosterone levels as compared to the visual-spatial memory advantage of men with higher T levels. Testosterone therapy results in men with andropause and postmenopausal women show improvement in memory and learning ability – even after short-term use of only six weeks.
Hypogonadal men experience a significant decrease in the following brain functions:
- Working memory
- Visual-spatial processing
- Episodic memory
- Processing speed
- Executive functions
Emotional well-being suffers immensely from testosterone decline. When examining low testosterone and the brain, depression is a common complaint among men and women. The connection between testosterone and depression is so great that before there were anti-depressants, testosterone was the treatment of choice. Today, doctors are once again finding that people who do not respond well to traditional anti-depressant therapy may get benefits from testosterone.
Women are more likely to experience depression at an early age. That backs up the connection between low testosterone and brain function regarding the emotional state. Men are increasingly susceptible to depression as they age, typically in conjunction with declining testosterone levels.
Studies have shown that low testosterone levels increase the risk of Alzheimer’s disease in men, as well as other types of neurodegenerative diseases, including Parkinson’s. Unfortunately, many doctors do not look at the connection between hormone levels and neurodegenerative diseases.
Other low testosterone effects on brain functions include difficulty concentrating and loss of self-confidence. Motivation, drive, and productivity may all suffer when a person experiences a decline in testosterone levels.
Low testosterone levels can lead to impaired learning, memory loss, depression, and overall cognitive decline.
Effects of Changes in the Brain on Testosterone Levels
Low testosterone has many causes, with the most common being that natural decline that occurs with aging. There are also issues affecting the brain that can lead to a decrease in testosterone levels.
What brain issues caused low testosterone to occur?
Here are some health conditions that can influence testosterone production:
- Brain Injury
A head injury, such as resulting from a fall, a severe blow to the head, an accident, or even a sports injury can lead to impaired functions in the hypothalamus or pituitary gland. If one or both of these endocrine releasors are damaged, then the hormones they secrete may alter in supply. It is up to the hypothalamus to measure blood testosterone levels to determine if more is necessary. If the hypothalamus is damaged, it may not be able to measure levels accordingly or to secrete the hormones required to tell the pituitary gland to release luteinizing hormone and follicle-stimulating hormone to the testes and the ovaries.
Also, if the pituitary gland is injured, it cannot respond to signals from the hypothalamus. It is common for a person to experience low testosterone after brain injury occurs.
- Brain Tumor
Just as with a brain injury as discussed above, a tumor in either the hypothalamus or pituitary gland can produce the same results. Depending on the tumor, a person may experience either a decline in the production of LH and FSH or an increase, which can result in elevated testosterone levels. It is more common to experience low testosterone, and the brain cannot produce enough of the signaling hormones as a result of the tumor.
- Surgery, Radiation, Medication
When an injury or tumor is present, doctors will typically respond with either surgery, radiation, chemotherapy, or some other form of treatment to correct the issue at hand. Although it would seem that removing a tumor should eradicate the problem, that is not always the case. In some instances, these treatments can also negatively influence testosterone production, necessitating the need for testosterone therapy.
- Brain Inflammation
Although not brought about by the damages listed above, the low testosterone – brain inflammation connection is another one to mention. In a 2013 study, researchers found that obesity (often associated with low testosterone) leads to brain inflammation. Low levels of testosterone worsen the inflammation. In studies of diet-induced obese mice with substantial inflammation levels, their brains were less able to support nerve cell growth and survival. Obesity has long been shown to lower testosterone levels. Inflammation of the CNS can increase the risk of conditions such as Alzheimer’s disease and type 2 diabetes.
The hypothalamus and pituitary gland in the brain regulate hormone release that stimulates testosterone production.
Testosterone Therapy and Brain Repair
It should be apparent by now that low testosterone and the brain are connected in ways that can adversely affect daily life. From cognitive decline to a loss of emotional well-being, men and women can see their lives change for the worse if testosterone levels get too low.
The situation is not as bleak as it may seem. Testosterone therapy is one of the oldest and most researched methods of hormone replacement. It is a safe and effective way of boosting low testosterone levels back to a healthy state. When that occurs, it allows the supplemental testosterone to support most of the natural androgen functions. The only thing testosterone replacement therapy cannot do is improve spermatogenesis and fertility in males. Only testosterone from the testes can do that.
When dealing with low testosterone and the brain declining to the point where daily functions are impacted, we find that testosterone therapy can offer significant benefits. For men and women facing these issues, the following benefits are likely:
- Improved focus
- Faster learning
- Better cognitive performance
- Enhanced memory
- Increasing visual and verbal memory
Degenerative conditions such as Parkinson’s, Alzheimer’s, and Multiple Sclerosis (MS) may also benefit. Testosterone is a hormone that can help prevent the buildup of beta amyloid plaque responsible for the brain destruction found in patients with Alzheimer’s disease. In a 2004 study, researchers found that each 10-unit increase in testosterone levels lowered Alzheimer’s development risk by 26 percent.
Multiple Sclerosis is one of the neurodegenerative diseases that affect the central nervous system (CNS). In one study of ten men who suffer from relapsing-remitting MS, the initial phase of six months was without testosterone therapy. During this time, they experienced a loss in focal gray matter. The men then received testosterone treatment for 12 months. During that time, there was no further loss of gray matter. Instead, the men experienced a significant increase in right frontal cortex gray matter, pointing to the neuroprotective effects of testosterone.
For patients with Parkinson’s disease, testosterone deficiency is an often-unrecognized form of co-morbidity. Many of the symptoms of low testosterone are often attributed to non-motor manifestations associated with Parkinson’s. Treatment with testosterone therapy can help to improve symptoms such as anxiety, sexual dysfunction, depression, low libido, and fatigue.
Depression is a serious issue for many aging adults. When depressive disorders were combined with low testosterone and lack of libido, testosterone therapy proved as effective as using serotonin reuptake transporters.
To back up the indirect benefits of testosterone via estrogen boosting, estradiol has been shown to slow down age-related memory decline. That is why estrogen is widely accepted as having benefits for brain functions. Since the enzyme aromatase converts excess free testosterone to estradiol, testosterone therapy can have a double benefit for adults low in both hormones.
The use of testosterone therapy can lead to multiple cognitive and emotional benefits for men and women as they age. HGH Doctor hormone clinic can help determine if testosterone therapy might benefit you during a free telephone consultation.
- WebMd: Low Testosterone and the Brain
- NCBI: On the effects of testosterone on brain behavioral functions
- Medical press: Obesity leads to brain inflammation, and low testosterone makes it worse