After 6 weeks, psychological tests indicated that about half the participants responded to DHEA therapy, with an overall enhancement of mood scores by 30.5%. This is close to the response rate of antidepressant drugs.
Researchers have different theories about how DHEA alleviates depression. Both DHEA and DHEA-s can cross the blood-brain barrier and interact with the brain directly. DHEA can affect serotonin, GABA receptors, and other brain factors. A recent study indicates it might modulate the serotonin signaling pathway. In addition, DHEA is the precursor for estrogen and testosterone which have been reported to enhance mood.

DHEA Inhibits Cancer Cell Proliferation

One study showed that patients with adult T-cell leukemia (ATL) had significantly decreased levels of DHEA compared to healthy controls. This has led some doctors to speculate that DHEA might be beneficial in treating this form of leukemia since DHEA has already been shown effective in treating hairy cell leukemia. Other cancer studies show DHEA inhibits cancer cell thymidine incorporation needed for cellular propagation and disrupts the oxidizing effects of chemical carcinogens. Scientists point out that DHEA functions not as an antioxidant, but as a modulator of the effects of chemical carcinogens on cells (American Journal of Hematology, 1996, 53[3]).

DHEA Protects against Brain Aging

Acetylcholine is a neurotransmitter that transmits nerve impulses from one brain cell to another..
In a study in Brain Research (Sept. 16, 1996), DHEA was administered to rats in order to measure the effect it produced on acetylcholine release into the hippocampus region of the brain. DHEA significantly increased acetylcholine release above pretreatment levels in all doses tested. At the highest dose, DHEA caused a fourfold increase in the release of acetylcholine compared to the control group. A study in Life Sciences (Oct. 4, 1996) showed that DHEA could protect against the precursor changes in brain cells that result in the pathological alterations associated with Alzheimer's disease.

DHEA Saves Skin

DHEA has powerful skin protective effects. A study published in the Journal of Surgical Research demonstrates that topically applied DHEA protects the skin's delicate blood vessels
DHEA has action against everyday insults as well. By maintaining skin immunity, DHEA preserves the ability of skin to react to cancer-causing, skin-destroying pollutants in air, food, and water. DHEA also has antioxidant action against peroxyl and superoxide free radicals.

Immune Function and DHEA

DHEA levels decline 80 to 90% by age 70 or later
In one study, scientists proposed that the oral administration of DHEA to elderly men would result in activation of their immune system. Nine healthy men averaging 63 years of age were treated with a placebo for 2 weeks followed by 20 weeks of DHEA (50 mg/day). After 2 weeks on oral DHEA, serum DHEA levels increased by three to four times. These levels were sustained throughout the study. Compared to the placebo, DHEA administration resulted in:

• An increase of 20% in IGF-1. Many people are taking expensive growth hormone injections for the purpose of boosting IGF levels. IGF stands for insulin-like growth factor and is thought to be responsible for some of the antiaging, anabolic effects that DHEA has produced in previous human studies.
• An increase of 35% in the number of monocyte immune cells.
• An increase of 29% in the number of B immune cells and a 62% increase in B-cell activity.
• A 40% increase in T-cell activity even though the total number of T-cells was not affected.
• An increase of 50% in interleukin-2.
• An increase of 22 to 37% in natural killer cells (NK) number and an increase of 45% in NK cell activity.
• No adverse effects noted with DHEA
  administration.

The scientists' conclusion: "While extended studies are required, our findings suggest potential therapeutic benefits of DHEA in immunodeficient states." (Journals of Gerontology, Series A, 1997, 52[1])