Can Low Testosterone Cause Depression?

According to the World Health Organization, approximately 350 million people live with depression globally. It is the leading cause of disability worldwide. There is no single cause of depression, which is often the result of complex interactions between social, psychological, and biological factors. One of these factors may be abnormal levels of the sex hormone testosterone.¹

What is testosterone?

The major sex hormone in males, testosterone, plays an important role in the development of male sex organs and the onset of puberty. It also affects muscle size and strength, bone density, sex drive, and sperm production. 

In males, testosterone is produced in the testes. The brain sends signals to the pituitary gland, which then instructs the testes to produce testosterone.

From puberty to age 40, testosterone levels in males remain relatively stable. But as men age, there are fewer signals from the pituitary gland instructing the testes to produce testosterone. From age 40, men experience a gradual decrease (1-2% per year) in the level of free, active testosterone in the body.

Testosterone is one of several androgens (male sex hormones) that are also produced in females. Because the average serum testosterone levels are between 10- and 20-fold higher in males than in females, testosterone is considered a male sex hormone.

However, females are more sensitive to fluctuations in testosterone levels than men. In females, testosterone, which is produced in the ovaries and adrenal glands, affects ovarian function, bone strength, and libido. In both males and females, testosterone may contribute to the normal functioning of the brain, affecting mood and cognitive functioning.

Symptoms of low testosterone

More than a third of men over 45 may have testosterone levels that are lower than the range considered normal. In the United States, testosterone deficiency occurs in approximately 6% of the male population (aged 30–79).²

In addition to the reduction in testosterone levels that occurs with aging, males may also experience a drop in testosterone levels as a result of conditions that affect the testes or the pituitary and hypothalamus glands.

Low testosterone levels may result in:

• Loss of muscle mass

• Reduced body and facial hair 

• Brittle bones 

• Low libido and reduced sperm count 

• Increased breast size

• Reduced energy

• Decreased mobility 

If you have low testosterone, you may also experience increased irritability, difficulty concentrating, and other symptoms of depression.

In females, the removal of the ovaries or diseases of the pituitary, hypothalamus, or adrenal glands can result in low testosterone levels. Estrogen therapy, which increases sex hormone binding globulin, can also reduce the amount of free, active testosterone in the body. 

As with males, females with low testosterone levels may experience low libido, reduced bone strength, and changes in mood and cognitive function. 

What is depression?

According to the Pan American Health Organization, 5.9% of people in the United States are living with some form of depression. Depression is a broad term used to describe a collection of mood disorders marked by depressive episodes.³

Symptoms of depression

During a depressive episode, you may experience:

• Depressed mood (sadness, irritability, or emptiness)

• A loss of interest in activities that normally interest you

• Poor concentration

• Strong feelings of guilt or low self-esteem

• Disrupted sleep

• A sense of hopelessness about the future

• Changes in weight or appetite

• Persistent thoughts about death or suicide

• A lack of energy

These symptoms (not necessarily all of them) must last at least two weeks and interfere to some degree with normal daily functioning to be considered a depressive episode. 

In addition to major depressive disorder and dysthymia (a chronic form of mild depression), other depressive disorders recognized by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) include perinatal depression, seasonal affective disorder, disruptive mood dysregulation disorder, and premenstrual dysphoric disorder. Bipolar disorder is, in many cases, marked by both depressive and manic episodes. 

Risk factors for depression

Social, psychological, and biological factors all play a role in the development of depression. 

Risk factors for depression include a family history of depression, major life changes, stress or trauma, certain physical illnesses (such as diabetes, cancer, cardiovascular disease, and Parkinson’s disease), hormonal changes, and certain medications.

The link between testosterone and depression

More than 50 years ago, researchers began hypothesizing that there might be a link between testosterone levels and depressive symptoms. 

Hypogonadism (a clinical condition defined by very low testosterone levels) has been associated with depression in several studies, and treatments for prostate cancer that reduce testosterone levels have been linked to an increased risk of depression.⁴

A study of older men in Iran found a significant inverse relationship between serum testosterone levels and depressive symptoms (as testosterone levels decrease, depressive symptoms increase).⁵

This led researchers to speculate that the increased prevalence of depression in old age may be associated with an age-related decline in testosterone levels.

While many studies have focused on the relationship between low testosterone levels and depressive symptoms, research suggests that high testosterone levels may also be linked to an elevated risk of depression among men. This has led some researchers to hypothesize that low testosterone and high testosterone are each associated with specific depressive symptoms.⁶

Testosterone and depression in women

While the majority of studies investigating the relationship between testosterone and depressive symptoms have focused on male subjects, testosterone also affects female behavior. 

Studies investigating the relationship between women have produced inconsistent results. Some suggest that female patients with depression have lower serum testosterone levels than control groups, while others suggest that female patients with depression have higher serum testosterone levels than controls.

A 2021 meta-analysis and Mendelian randomized study found that neither increased nor decreased testosterone levels in women caused depression. However, comparatively, women with depression did display deviations from the norm in testosterone levels. 

In premenopausal women with depression, there was an overall increase in testosterone levels compared to women of a similar age without depression.

 In the postmenopausal subgroup, the women with depression showed decreased testosterone levels. The researchers concluded that testosterone does not play a causal role in female depression and that changes in testosterone levels are a result of the depression itself. Put simply, depression occurs before the changes in testosterone. 

Testosterone, depression, and gut microbiota

The gut microbiota (the different types and quantities of bacteria in the gut) of people with depressive disorders has been shown to differ from that of healthy control groups. In particular, people with depressive disorders have been shown to have an abundance of the type of bacteria capable of degrading steroids. 

A recent study that investigated the relationship between testosterone deficiency, depression, and gut microbiota found that certain bacteria could degrade testosterone, leading to lower levels of serum and brain testosterone and depressive symptoms.²

The study suggests that gut microbiota may be a modifiable risk factor for preventing low testosterone or depressive symptoms. 

Can testosterone therapy reduce depressive symptoms?

Multiple studies have demonstrated that testosterone has the potential to improve mood and mental health in both men and women. 

The Testosterone Trials, which were set up to establish whether testosterone supplementation could benefit older men with age-related low testosterone, found that testosterone treatment was associated with small but significant benefits related to mood and depressive symptoms.⁷

A 2018 meta-analysis of 27 randomized placebo-controlled clinical trials found that testosterone treatment was associated with a significant reduction of depressive symptoms in men, particularly in the cases of participants who received higher doses of testosterone.⁸

Other treatment options for depressive symptoms

Depression is typically treated with antidepressant medications, psychotherapy, or a combination of antidepressants and psychotherapy. There are several different types of antidepressants, and your doctor can help you find one that works well for you. 

By teaching you new ways of thinking and behaving, psychotherapy can help you rewire your brain and change habits that reinforce depressive symptoms.

In addition to treatment, there are measures that you can take to manage your depression. These include:

• Daily physical activity

• Consistent sleep patterns (going to bed and waking at the same time each day)

• Regular, healthy meals

• Connecting with family and friends

• Avoiding alcohol, nicotine, and drugs

How can I get help?

Depression can interfere with your daily functioning, including your ability to work and maintain relationships. More severe forms of the condition can be life-threatening. Globally, almost a million people commit suicide every year, and a far greater number (approximately 20 million people) attempt to take their own lives but do not succeed. 

If you feel an overwhelming sense of despair or are having thoughts of suicide, talk to your healthcare professional. You can also seek help via one of these support systems:

• Suicide & Crisis Lifeline: call or text 988 for confidential support

• Crisis Text Line: text ‘hello’ to 741741 to connect with a crisis counselor who can provide you with support and helpful information

• Veterans Crisis Line: call 1-800-273-TALK and press 1, or text 838255

The lowdown

Abnormal testosterone levels (both high and low) have been associated with depressive symptoms in both men and women. The nature of this relationship is not yet clear, but studies have shown that in cases of low testosterone in men, testosterone replacement therapy can help to reduce depressive symptoms.