The study of neurohypophyseal peptides in various neuropsychiatric disorders is of interest because the hypothalamo-posterior pituitary axis is directly influenced by modifications of central neurotransmitter metabolism involved in behaviour control. Moreover, the main neurohypophyseal peptides, namely vasopressin and oxytocin, are themselves capable of modifying behaviour. In this paper the author discusses current understanding of the anatomy and physiology of the main central vasopressinergic and oxytocinergic pathways, followed by a description of the principal actions of exogenously administered vasopressin and oxytocin on human behaviour. Finally, modification of endogenous neurohypophyseal function encountered in different pathological states are described.
