A number of substances with central nervous effects (antidepressants, antipsychotics, antiepileptics) are known to lead to retention of free water via an antidiuretic hormone (ADH) effect and thus to hyponatremia, which is often a cofactor of delirious syndromes; antidiabetic drugs may contribute by inducing hypoglycemia. Here, AVP is linked to Hyponatremia.