Depression: Is Yeast a Missing Link?

Depression: Is Yeast a Missing Link?

Depression: Is Yeast a Missing Link?

Carolyn Dean, M.D., N.D. and Carol Beck, M.S.

Depression casts a shadow over the lives of 19 million Americans, two-thirds of them women. The precise cause, in many cases, remains a mystery. Genetics, brain chemistry gone bonkers, even environmental depredation have all been mentioned, and documented, as causes of depression.

We suggest that systemic yeast overgrowth is another often-overlooked cause of depression.

In his latest book, The Yeast Connection and Women's Health, Dr. William Crook says he and his colleagues found a very strong link between Candida albicans yeast overgrowth and depression in patients who had a history of any of the following:

Use of antibiotics, especially long courses of antibiotics

Use of birth control pills

Persistent digestive distress

Recurring vaginal yeast infections

Dr. Crook made the fascinating discovery that 85 percent of women suffering from depression who had even one of the above elements in their history found relief from depression and a host of other symptoms by following his Anti-Candida Treatment Plan. Why? Let's look at the cycle of yeast overgrowth in the body and how it affects various body systems, including brain chemistry.

It starts simply enough–you get sick and you take antibiotics or cortisone-containing drugs to feel better. You get sick again and take medications to treat your symptoms. This happens many times over a period of years. You may also be taking birth control pills. Over time, the natural, healthy balance of yeast and microorganisms in your intestinal tract alters its balance in response to the medications.

Antibiotics (literally meaning anti-life) indiscriminately kill bacteria throughout your system. This is good if you have bacterial pneumonia or an infected wound, because the "bad" bacteria could eventually threaten your life. However, the antibiotics also kill the "good" bacteria, especially those that live in your digestive tract and help digest your food. This upsets the natural balance of bacteria and yeast that usually live in harmony in your digestive tract, since yeast is not affected by antibiotics.

The more often you take antibiotics or cortisone-containing drugs, the more disturbed your natural balance of intestinal flora. The medical term for this is dysbiosis.

As the flora in your intestine becomes increasingly out of balance, two things happen: the lining of your intestines weakens and you develop a craving for sugars and carbohydrates to try to feed the unnaturally large amount of yeast in your intestine.

The more sugar and carbs you eat, the more the yeast grows out of balance and the larger your appetite becomes for even more sugars and carbs. In response, the lining of your intestine weakens due to the unnatural balance of microorganisms and the increasingly weakened immune system.

Toxins and food allergens normally cannot penetrate your intestinal lining. However, under yeast overload conditions yeast change from a budding form to a mycelia form that penetrates the intestinal lining allowing toxins and food allergens to leak into the bloodstream. The more they enter the bloodstream, the weaker your immune system becomes and the more "sick all over" you feel. See Dr. Crook's book, The Yeast Connection and Women's Health for more detailed descriptions of this cycle known as "leaky gut syndrome" and its effect on chronic health conditions.

Candida toxins, basically products of their metabolism or toxins released when they die, number in the dozens. In fact, by 1977, 79 different toxins had been identified. Two in particular, are alcohol and acetaldehyde. In some cases of severe intestinal Candida, people have measurable levels of alcohol and acetaldehyde in their blood. And they feel intoxicated just as if they were drinking alcohol. We know about acetaldehyde because it has been shown to be breakdown product of alcohol that is responsible for hangover symptoms.

When acetaldehyde reacts with the neurotransmitter, dopamine, it can cause mental and emotional disturbances such as anxiety, depression, poor concentration, and feeling spaced-out. If you look up the toxicology of acetaldehyde you find that it adversely affects many tissues and organs in the body.

Is it any surprise, then, that depression and fatigue are two of the most common complaints of people suffering from dysbiosis? Is it any wonder that yeast overgrowth plays a role in the symptoms of such a wide variety of chronic health conditions? See for more information about overcoming these conditions and finding relief and health.

Without proper treatment for Candida, a whole cascade of problems creates a downward spiral that triggers a cascade of symptoms and the following scenario.

You feel more sick, so,

The dysbiosis becomes more severe, and 

Candida toxins directly affect your brain making you feel depressed

Candida overgrowth causes sugar and carb cravings and your diet spins more out of control

More nutritional deficiencies develop and 

More endocrine disturbances occur,

Further weakening your immune system,

Promoting a release of brain chemicals, disturbing the normal balance of mood-regulating chemicals in your brain and 

Causing even more depression and/or anxiety.

Unfortunately, there has not been any significant research on yeast-related causes of depression since Dr. Crook introduced the topic in an article in the Journal of the American Medical Association 20 years ago in 1984.

And sadly, there is no magic bullet drug treatment.

However, Dr. Crook did formulate a successful treatment for dysbiosis and the many symptoms that accompany Candidiasis. The treatment involves a five-step approach:

Diet and exercise

A diet rich in meats, fish, chicken, eggs, seeds and nuts, vegetables, and oils (free range and organic) while avoiding sugars, carbohydrate-rich foods, and fermented products like vinegars and preserved meats begins to restrict the amount of fuel the yeast in your intestine has available to it. With time, in combination with the appropriate anti-candida supplements (see below), your digestive tract returns to its natural, healthy balance of organisms and your immune system becomes stronger. In turn, your brain chemistry returns to normal and your low moods stop.

Once you've started on the diet, exercise, even if for only five minutes a day, will also begin to rebalance the levels of neurotransmitters in the brain.


    Probiotics. These supplements contain friendly bacteria that help you keep a natural, healthy balance of microorganisms in your digestive tract. There are many different forms and brands of probiotics available in foods and pills and capsules. However, to be effective, they need to be able to bypass the harsh stomach acid and deliver at least 1 billion live organisms to the intestines.

    Digestive Enzymes. These supplements provide a combination of digestive enzymes to help maintain a natural, healthy digestion. Most good products contain several enzymes to promote optimal digestion. It's also helpful to include phyto-nutrients to help maintain and calm an upset stomach. Among their many benefits, digestive enzymes help you comfortably digest problem foods like broccoli, cauliflower, beans, fruit, and milk.

    Herbs and nutrients to inhibit the growth of Candida albicans. In addition to prescription antifungal medications, a variety of herbs and nutrients can help support a healthy balance of intestinal bacteria, reining in yeast growth. Among the nutrients that work together to stop candida overgrowth: caprylic acid, pau D'Arco, oregano oil, black walnut, grapefruit seed extract, garlic, beta carotene, and biotin.

    Vitamins and minerals. Taking a good quality daily multivitamin and mineral supplement helps supply your body with the nutrients it needs to help you regain your health. A good calcium, magnesium and vitamin D supplement are also essential to optimal health, especially for women.

Avoid exposure to chemicals. Paints, household cleaners, perfumes and scents may cause allergic reactions. Chemical sensitivities are very common in people with yeast overgrowth.

Address emotional and psychological issues. This step also profoundly impacts your appetite for certain foods and helps balance the chemistry of your body and brain.

Work with a kind and caring health professional. Dysbiosis is a tremendously complex, multi-faceted condition that is often difficult to understand. Use the Physician's Packet and the referral service available on to find a health care professional in your area to help you find the relief you're looking for and to take charge of your health.


Iwata, K., and Yamamota, Y. Glycoprotein Toxins Produced by Candida Albicans. Proceedings of the Fourth international Conference on the Mycoses, June, 1977, PAHO Scientific Publication #356. and Iwata, K., Recent Advances in Medical and Veterinary Mycology, University of Tokyo Press, 1977.

Feldman, D. et al., Steroid Hormone Systems Found in Yeast. Science Aug 31, 1984;225:913-915.

Crook WG, Depression associated with Candida albicans infections.

JAMA. 1984 Jun 8;251(22):2928-9.

Truss, C. 0. Metabolic abnormalities in patients with chronic candidiasis: the acetaldehyde hypothesis. J. Orthomol Psychiatry. 1982;3:66-93.

Hunnisett, A., Davis, H.J., Gut Fermentation (or the "Auto-Brewery") Syndrome: A New Clinical Test with Initial Observations and Discussion of Clinical and Biochemical Implications. Nutr Med 1990;1:33-38.


Carolyn Dean, M.D., N.D., is medical advisor to Woman's Health Connection at and is featured on the Web site's "Ask A Pro" page. Her latest books are The Miracle of Magnesium and Natural Prescriptions for Common Ailments.

Carol Beck, M.S., is a consultant, therapist, and author of Full and Fulfilled: The Science of Eating to Your Soul's Satisfaction (written with Nan Allison MS, RD, LDN) and Nourishing Your Daughter: Help Your Child Develop a Health Relationship With Food and Her Body. Carol serves as health advisor of Woman's Health Connection and

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