CFS is a rare condition that affects some women after childbirth. In this disorder, mothers continue to produce breast milk for more than six months, even if they are not breastfeeding. Their menstrual cycles may stop or become irregular, and their hormone levels are disrupted.
A key feature of CFS is high prolactin levels. Prolactin is the hormone that makes milk. Normally, prolactin drops after childbirth, but in CFS, it stays high. So, how is CFS influenced by psychological stress? Read more to find out.

The link between psychological stress and pituitary disregulation

Our bodies are complex machines, equipped with the right built-in tools to respond to stress. Stress can be physical, like injury or illness or psychological, like exams, work pressure, or emotional strainWhen stressed, the hypothalamic-pituitary-adrenal (HPA) axis is activated. Think of the hypothalamus as a conductor guiding the body’s response. It tells the pituitary gland, the “master gland,” to release hormones that prepare the body for stress.

Two main stress systems exist:

1. Sympathetic-adrenal-medullary (SAM) system, which triggers quick “fight or flight” reactions with adrenaline and noradrenaline
2. The HPA axis, which releases cortisol, a hormone that helps the body fight chronic stress
3. The hypothalamus, the pituitary gland, and the adrenal glands make up the HAP axis

The hypothalamus is a part of our brain located in the diencephalon. It's also known as the “command centre” because it sends signals to other endocrine glands. In other words, the hypothalamus is like an experienced conductor leading an orchestra, our other organs, through an elaborate musical piece. After the hypothalamus reads the music sheet, the stress signals our body sends, it responds by activating the pituitary gland. The pituitary gland is also known as the master gland because it can secrete a wide range of chemicals.

The pituitary gland has two parts: the anterior (front) and the posterior (back). When the brain senses stress, the hypothalamus releases corticotropin‐releasing hormone CRH, which signals the anterior pituitary to release adrenocorticotropic hormone ACTH. ACTH then signals the adrenal glands to release cortisol, the main stress hormone.

During pregnancy, prolactin, a hormone whose release is stimulated by the baby suckling at the mother’s breasts, is also released from the anterior pituitary. In a typical menstrual cycle, prolactin is usually low, except for a small rise before ovulation due to estrogen. After childbirth, prolactin rises to allow milk production, then drops within six weeks.

In CFS, prolactin stays high, so milk keeps being produced. High prolactin also stops the normal hormone signals that trigger periods. In men, high prolactin can reduce libido, cause headaches, and affect sperm production.

How prolactin interacts with stress

Prolactin is mainly made in the anterior pituitary gland, but small amounts can also be made in the breast and immune cells. Its release is normally controlled by dopamine from the hypothalamus. Dopamine binds to D2 receptors in the pituitary to stop prolactin production.

When stressed, the HPA axis works harder. Stress hormones like cortisol rise to prepare the body for fight or flight. High prolactin during lactation can actually reduce the stress response, while blocking prolactin increases stress reactions. This shows that prolactin helps regulate stress during breastfeeding.

Prolactin is also influenced by other things like our daily rhythms, seasonal changes and of course stress. Studies on short-term and chronic stress showed that in animals, a sudden stress (like being restrained) causes prolactin levels to rise quickly but briefly, followed by a longer phase where levels drop. In studies where animals were exposed to mild stress over weeks, prolactin levels didn’t change at first. This suggests that the body can adapt to repeated stress, reducing the prolactin response over time. 

In humans, early life experiences, like childhood trauma, may make some women more likely to have high prolactin later in life. However, research on adults with post-traumatic stress disorder (PTSD) is mixed - some studies show prolactin levels decrease, some show no change, and some show an increase. Other findings suggest that prolactin regulation may be disrupted by trauma or PTSD, and the effects can differ between men and women. 

Chiari-frommel syndrome

Chiari‐Frommel Syndrome is a rare disorder in which patients show continuous postpartum or postlactation lactation for more than 6 months after childbirth. This means that mothers continue to lactate and produce milk, regardless of whether they breastfeed or not. This phenomenon is called galactorrhea from the Greek words galaktos (milk) and rhoia (flow). Other symptoms of the disease include breast engorgement, which is swelling and discomfort from milk accumulation, amenorrhea or the absence of menstrual periods, obesity, and uterine and ovarian failure. Some cases also show hypothyroidism due to pituitary or hypothalamic dysfunction. The clinical picture of a patient with CFS is usually a young woman, 17–35 years, poorly nourished. The incidence of Chiari‐Frommel Syndrome is extremely rare, and diagnosis is done through hormone level testing, especially prolactin and gonadotropins, imaging of the pituitary gland, and exclusion of other causes.

The role of prolactin

In CFS, patients show high levels of prolactin. Prolactin is a hormone that is essential for stimulating lactation. During pregnancy, especially in the second and third trimesters, prolactin is present in high levels (about 50 ng/ml) in both fetal and maternal plasma. After birth, it declines to about 1/10th of the original amount within 6 weeks. These low levels of prolactin (about 5 ng/ml) are the normal levels present in the plasma of both males and females. During normal menstrual cycles, however, estrogen can cause a spike in prolactin during pre‐ovulation.

In CFS, prolactin levels remain high, so mothers continue to produce milk for longer than needed. In addition, high levels of prolactin lead to the absence of menstruation, or amenorrhea. This is because prolactin isn’t inhibited by GnRH. In males, elevated prolactin can lead to headaches, decreased libido, and reduced spermatogenesis due to its effect on the hypothalamic–pituitary–reproductive axis.

The connection between stress, the pituitary gland, and CFS is not yet fully understood. One idea is that long-term stress may affect hormone signals, keeping prolactin high after birth and prolonging CFS; however, more research is needed to establish a definite pathway between psychological stress, pituitary dysregulation and CFS.

Summary

• CFS is a rare disease in which young mothers continue to secrete breast milk for more than 6 months after pregnancy. Common symptoms include hormonal imbalances, loss or disruption of menstrual cycles and cervical atrophy. Some clinical hallmarks are hyperprolactinemia, amenorrhea and galactorrhea. The condition usually resolves by itself, but in rare cases, interventions like dopamine agonist therapy (e.g., bromocriptine) or surgical removal of a pituitary adenoma may be needed
• Physiological stress is described as the body’s reaction to internal or external challenges that disturb the normal state of rest, known as homeostasis. Stress can disrupt the pituitary gland through overactivation of the hypothalamic–pituitary–adrenal (HPA) axis and changes in hypothalamic dopamine regulation. This leads to dysregulation, for example, through prolonged cortisol release and reduced inhibition of prolactin. The result is hyperprolactinemia, or abnormally high levels of prolactin, which possible disrupt reproductive hormones
• The link between CFS, stress, and pituitary dysregulation isn’t well studied yet. The proposed hypothesis now is that chronic psychological stress may alter hypothalamic and pituitary signalling in a way that causes high prolactin levels after birth, contributing to the persistence of CFS symptoms. However, more research is needed

FAQs

Is the HPA the only neuroendocrine axis involved in stress?

No, there are actually 2 main neuroendocrine axes involved in dealing with stress: the sympathetic adrenal medullary system (SAM) and the hypothalamic–pituitary–adrenal (HPA) axis (the main stress response system of interest in this article). When experiencing acute stress, for example, a near‐miss accident, the main axis activated is the SAM, which releases chemicals called catecholamines. These include adrenaline, noradrenaline, and even small doses of dopamine, and together they act to start the fight‐or‐flight response. This leads to the activation of the HPA axis and the release of cortisol, a characteristic marker of psychological stress.

Is cortisol the only steroid hormone released from the adrenal cortex in psychological stress?

No, researchers have found that other hormones, like sex hormones and mineralocorticoids, are also secreted. Steroid hormones are a group of fat‐soluble molecules that come from cholesterol and act as signalling molecules in the body. Mineralocorticoids are steroid hormones that help modulate electrolyte and fluid balance. An example is aldosterone, which increases sodium reabsorption in the kidneys.

Is chiari‐frommel syndrome the only name?

No, the Chiari‐Frommel Syndrome is generally known by different names such as Frommel–Chiari, Lactation‐Uterus Atrophy, and Postpartum Galactorrhea‐Amenorrhea Syndrome. Other disorders related to the syndrome are Ahumada‐del Castillo Syndrome and Forbes‐Albright Syndrome.