Another study, by psychiatrist John Greist at the University of Wisconsin, revealed that one group of seriously depressed patients benefited more from a ten-week session of therapeutic running than another group benefited from traditional therapy. To summarize research findings on exercise as a treatment for depression: * To be effective, vigorous exercise must be done regularly no less than three times a week, and preferably at least five times a week, for periods lasting between thirty minutes and an hour. (Dr. Kostrubala uses an hour as a goal.) * Although running and running combined with walking are the most commonly used therapeutic forms of exercise, any regular aerobic exercise is likely to produce the same {210} antidepressant effects when done for proportional periods of exertion. * Studies over the past ten years show that lessening depression by means of exercise is most successful for persons with mild to moderate depression, but vigorous exercise tends _not_ to benefit patients with _severe_ depression.[2] [2] John H. Griest and James W. Jefferson, _Depression and Its Treatment _ (Washington, DC: American Psychiatric Press, 1984), p. 63. _Lessening Anxiety_ Therapeutic running also tends appreciably to lessen anxiety. A research study conducted by Dr. Herbert A. deVries of the University of Southern California School of Medicine and Gene M. Adams of USC's Gerontology Center found that fifteen minutes of moderate exercise diminished anxiety more in people aged fifty-two to seventy than did 400-milligram doses of meprobamate, a widely prescribed tranquilizer. _For Schizophrenics_ Therapeutic running also seems to benefit schizophrenic patients. Schizophrenia is a complex, difficult-to-treat illness that affects approximately 1 percent of the world's population. It is no respecter of particular cultures. There are many forms of the illness, but all are characterized by disabling blockages to normal human interrelation, strange behavior, loss of contact with reality, and withdrawal, paranoia, or hallucinations. Again, Dr. Kostrubala has attempted to help patients with this condition through a combined program of medication, psychotherapy, and therapeutic running. Although he is careful to emphasize that controlled studies have yet to be made, his judgment about the patients he has treated is that ... using this form of running therapy ... [I] have seen them change dramatically. They begin to lose their symptoms; medication can be reduced and often discontinued; and they have picked up the course of their lives until several are no longer recognizable as schizophrenics at all--even by professional observers.[3] [3] Thaddeus Kostrubala, _The Joy of Running_ (Philadelphia: J. B. Lippincott, 1976), p. 129. {211} ... I have come to the conclusion that running, done in a particular way, is a natural form of psychotherapy.[4] [4] Kostrubala, _The Joy of Running_, p. 119