According to Āyur-vedic treatment, the entire physiological system is conducted by three elements, namely, vāyu, pitta and kapha (air, bile and mucus). Secretions within the body transform into other secretions like blood, urine and stool, but if there are disturbances in the metabolism, the secretions turn into kapha (mucus) by the influence of the air within the body. According to the Ayur-vedic system, when the secretion of bile and formation of mucus disturb the air circulating within the body, fifty-nine varieties of disease may occur. One of such diseases is craziness.
Ref >> Srila Prabhupada Vani.