Since the time my book on came out last year, I have been pleasantly surprised about the positive reader feedback regarding a small part of the book that discusses a little-known naturopathic called "hydrotherapy."

Hydrotherapy is a simple at-home remedy that can provide substantial benefit with minimal effort. Hydrotherapy is the application of water to the body surface to help it heal and feel better. I thought I’d share some of basics of this old-time therapy with you to see if you would like to give it a try.

Old-Time Nature Cure Theory

Humans used to spend a lot more time outside–and we were continually exposed to great variations in climate, humidity, and weather. And, there were occasions we would be submerged in different waters of various temperatures too. Old-time naturopathy finds some of its healing roots here. Hydrotherapy has actually been in use since ancient times as a way to balance the body and mind. According to Hippocrates, water therapy "allays lassitude" (physical or mental weakness). Later, one German water cure from the 1800s often used various applications to help treat disease (Barry and Lewis, 2006).”

How Does Hydrotherapy Work?

Applying water of different temperatures to our skin can change our physiology and mood. When humans take a cold swim, once over the initial shock of the cold, it is usually very invigorating. This is because wet and cold causes our surface vessels to vasoconstrict (tighten up), making blood move from the surface of your body to the core, as a means to conserve heat. Not only does it conserve heat, it also reflexively bathes the brain and vital organs in fresh blood. This movement will bring , oxygen and also help gently detoxify the area. Warm water will make the vessels vasodilate (relax) which will bring blood up to the surface. This helps blood move back, away from the core, cleaning out the core.

Throughout our millions of years of evolution, primates have endured physiological stressors like temporary cold and heat temperature changes as a part of daily life. Hydrotherapy is designed to take advantage of the natural body reaction to these changes in order to make the body stronger. It has been theorized that brief changes in body temperature like a cold swim or warm bathing could help brain function.

Medical research has supported the use of hot and cold baths, as well. Decreases in (like cortisol) have been reported with water bathing (Toda et al., 2006). It has also been shown that water bathing may also help the balance of the feel-good neurotransmitter serotonin (Marzsziti et al., 2007). Footbaths have been shown to induce relaxation by decreasing that stress response, where it has been noted that the sympathetic (the ‘fight or flight’ part of our nervous system) was able to calm down (Yamamoto et al., 2008). Thomas Jefferson is well known to have used a cold foot bath every morning for 60 years to maintain his good health. In fact, when I visited his Monticello home a few years ago, I saw the watermarks where his foot bath sat at the edge of the bed. He was carrying on the German naturopathic water cure tradition.

Water Therapy vs. Drug Therapy for Mood?

While used extensively for hundreds of years as a part German water cure, relatively little clinical research has been done to study hydrotherapy for mood. But there is now some research to suggest benefit. One study suggests patients with can benefit from the mechanisms of hydrotherapy. Balneotherapy (using water baths for healing) was compared in one French study to paroxetine (Paxil), a leading SSRI . Using a randomized multicenter study for eight weeks, 237 patients with were assigned randomly to balneotherapy and 120 to the medication. The balneotherapy treatment consisted of weekly medical visits and daily bath treatments using natural mineral waters (sodium, calcium, magnesium and sulfates) for 21 days.

Every morning, patients were immersed in a bubbling bath (37°C for 10 minutes), then a shower with a firm massage-like pressure targeting the abdomen, area along the spine, and neck and arm regions for 3 min. Finally the legs neck, scapular, and spine area massaged under water for another 10 minutes. Sounds nicer than taking a drug, for sure. The anxiety scores showed an improvement in both groups, with a clearly superior result of the water therapy compared to the effect of the drug. Remission and sustained response rates were also significantly higher in the hydrotherapy group. Also, the water therapy was found to be safe and without side effects, as well (Dubois et al., 2010).

Another group of researchers from Virginia found that hydrotherapy may be useful to treat cancer and chronic fatigue, as well as be useful in the treatment of depression (Schevchuk, 2008). For the treatment of depression, it is suggested that cold exposure therapies may be the best choice. Since the density of cold receptors (the parts of our body that can sense cold) in the skin is thought to be three to ten times higher than that of warm receptors, the simultaneous firing of all skin based cold receptors from jumping into the cold may result in a positive therapeutic effect. It has also been shown that lowering the temperature of the brain is known to have neuroprotective and therapeutic effects and can relieve inflammation, a known mechanism in depressive illness. In addition, exposure to cold has been shown to activate the sympathetic nervous system, will increase the blood level as well as brain release of norepinephrine–an adrenal hormone that can help depressed people feel more ‘up’ naturally. The water therapy also can help increase production of beta-endorphins—‘feel-good’ molecules that give a sense of well-being.

Getting An Electric Shock, Without the Shock?

It has been thought that cold hydrotherapy may have a mechanism similar to another proven treatment: electric shock therapy. Electric shock therapy, sometimes known as or ECT, has long been used to treat drug-resistant forms of depression. These effects may well help the depressed patient, especially the patient who does well with increased release of norepinephrine. Patients respond well to duloxetine (Cymbalta), or other SNRIs that help increase the neurotransmitter norepinephrine, may get the best effects from cold water treatment.

An Easy Way to Try Hydrotherapy

I recommend patients with depression to use brief whole-body exposure to cold water in the form of a cold shower. Patients can start a shower at a comfortable warm temperature and slowly cool down the water over a five-minute period down to 68°F, at which point you can sustain for two to three minutes.

You can use a thermometer to check the temperature. This can be performed once or twice a day and may be continued for weeks to several months (Shevchuk, 2008).

Conclusion

Given its low-tech, low-cost use, shower hydrotherapy is worth a try as part of an overall naturopathic strategy for lifestyle, dietary and nutrient support. I have seen patients with both depression and anxiety benefit. I have also seen benefits for patients with migraines as well. Although mild cold stress seems to help the brain work better, please note that too much of a good thing may not be so good: animal research has shown that extreme cold stress may actually impair brain and cognitive function (Mahoney et al., 2007). So, check with your doctor for any contraindications, then start light, and maybe not join the polar bear club just yet. Nevertheless, those polar bear clubbers are clearly onto something good.

Peter Bongiorno ND, LAc is co-director of Inner Source Health in New York, and author of How Come They're Happy and I'm Not? The Complete Naturopathic Guide to Healing Depression for Good. Learn more here.