Depression: Is Yeast A Missing Link?

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 Woman’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 exciting discovery that 85% 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 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, these toxins and food allergens can 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. You’ll find more details at:

Without treatment, a whole cascade of problems creates a downward spiral that literally drags you down:

  • You feel sicker, so…
  • The dysbiosis becomes more severe, and…
  • Your diet spins more out of balance with sugar and carb cravings, so…
  • 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 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, so a holistic approach has been unused by most physicians in favor of the easy option: Prescription antidepressants that merely treat the symptoms and not the underlying cause, while causing a wide range of serious side effects.

Yeasts themselves produce dozens of different substances that can cause allergic responses. Seventy-nine such “antigenic substances” were identified before 1977.

One of the yeast-related problem-causers is acetaldehyde, a toxic substance that is produced in the metabolism of alcohol. When acetaldehyde reacts with the neurotransmitter, dopamine, it can cause mental and emotional disturbances such as anxiety, depression, poor concentration, and feeling spaced out.

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.

Treatment for dysbiosis and the symptoms that accompany it involves a five-step approach:

  1. Diet and exercise

    A diet rich in meats, fish, chicken, eggs, seeds and nuts, vegetables, and oils 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. A grocery list of foods to get you started is available on

    Once you’ve started on the diet, exercising, even if for only 5 minutes a day, will also begin to rebalance the levels of neurotransmitters in the brain. You’ll find help for deciding where to start with exercise on

  2. Supplements

    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 is also essential to optimal health, especially for women.

    You can find an excellent combination packet that will provide all the supplements you need at:

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

  4. Address emotional and psychological issues
    Emotional issues also profoundly impact your appetite for certain foods and help balance the chemistry of your body and brain.

  5. Work with a kind and caring health professional
    Dysbiosis is a tremendously complex, multi-faceted condition which 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 your 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. O., Metabolic abnormalities in patients with chronic candidiasis: the acetaldehyde hypothesis. J. Orthomol Psychia-try. 1982;3:66-93.

Hunnisett, A., Davis, H.J., Gut Fermentation (or the “Auto-Brewery”) Syndrome: A New Clinical Test with Initial Observa-tions 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 website’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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Written by Carolyn Dean

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