The response of 73 psychiatric outpatients to manipulation of their dietary intake of carbohydrate was studied with respect to symptoms of anxiety, depression, and dys-perception. In particular these symptoms were evaluated in three conditions: in ketosis, at the transition point from ketosis to non-ketosis, which I regard as an "Optimum Carbohydrate Level" (OCL), and at a higher carbohydrate intake, above 120 g per day. Ketosis was associated with improvement in 28 percent; the OCL was associated with improvement in 68 percent; and carbohydrate intake over 120 g per day was associated with improvement in 12 percent.
Over all, 82 percent of the patients reported improvement when combined results of both ketosis and OCL are considered. On the other hand, 60 percent reported some adverse effects, such as fatigue, nausea, weakness, headache, and a few episodes of palpitations. These were all transient, and most were improved after administration of potassium salts.
The history and biochemistry of the ketogenic diet and its use in medicine, particularly in the treatment of epilepsy and also obesity, is discussed.
The ketosis method of determining optimal carbohydrate intake appears to be a valuable addition to the practice of Orthomolecular psychiatry.