We have studied the relationship between intensity of manifestations and systemic acid base balance of the body in another group of subjects with various mental disorders. Of all the cases studied, the only condition in which a clear relationship could be shown was in manic depressive subjects. From patients presenting changes during the day, passing from periods of high excitation to calm, from deep depression to calm, we obtained hourly urine specimens. At the same time, observations of their mental state were made. The evaluations of mental condition were made by trained observers or members of the family using a conventional scale which permitted translation into graph. The pH of the urine samples was measured electrometrically. Curves of the pH and of the mental conditions were plotted having the common time as abscissa. A striking correlation between the two curves was found in the first investigations in manic patients. With the pH of the urine at higher values, the patient was calm, while the more acid urine corresponded to periods of intensive agitation. Figure 33 shows an example.

This correlation also could be demonstrated by administering acidifying and alkalizing substances to manic patients. Acidification through the administration of phosphoric acid was followed by a manifest increase in agitation while administration of an alkalizing agentósodium bicarbonate was followed by a period of calm. An opposite but less evident correlation was seen for several depressed patients. We must mention that the usual difficulty of judging accurately the degree of depression from one hour to another can explain this lesser correlation. Manic manifestations were much more readily evaluated.

The variations of the curve of the agitation

Fig. 33. The variations of the curve of the agitation of a 10-year old boy are opposite to that of the urinary pH, indicating an acid pattern.