Sven-Ake Bood, a doctoral student at Karlstad University did four studies involving the treatment of pain and stress-related disorders with the aid of a flotation tank. A control group that wasn't treated in a floating tank experienced no improvement in their health.

After seven weeks of flotation treatment, 22 percent of the participants -- all had stress-related long-term pain -- were entirely free of pain, 56 experienced a clear improvement, 19 percent felt no change and 3 percent felt worse.

"The treatment method can be used for several groups, such as people with whiplash injuries, fibromyalgia, depression and long-term stress-related pain," Bood said in a statement. "We can also see that a combination of treatment in a floating tank and traditional therapy can be effective. We are now moving on in our research and will be monitoring blood circulation in the capillaries, the oxygen uptake of the blood and how the body’s reflexes are affected."