Polydipsia consists of drinking too much due to abnormally great thirst. This occurs in medical disorder such as diabetes mellitus or diabetes insipidus, with medications such as corticosteroids or diuretics, and in serious mental illness, especially schizophrenia. Drinking too much water can result in water intoxication and hyponatremia (low blood sodium). Hyponatremia is also an uncommon side effect of psychotropic medications. Severe hyponatremia can be very dangerous, potentially resulting in serious neurological damage. Water intoxication and polydipsia are relatively common among people with serious mental illness. The cause of polydipsia due to mental illness is not understood. The treatment of polydipsia begins with medical evaluation to determine the cause, and subsequent management. Fluid restriction and cognitive behavioral therapies have been used.