Vasopressin in health and disease with a focus on affective disorders

The therapies of mood and anxiety disorders are not solved, because current antidepressants have delayed onset of therapeutic action and a significant number of patients are non-responsive. Research on the field was leaning towards neuropeptides as therapeutic targets. Vasopressin (VP) is a hot candidate, as beyond its peripheral actions VP is implicated in interneuronal communication and modulates the hypothalamo-pituitary-adrenal (HPA), the key stress axis, as well as behavioural functions. Affective disorders are stress related disorders and the most frequently occurring abnormality in depressed subjects is hyperactivity of the HPA. VP with nucleus paraventricularis hypothalami origin is a direct adrenocorticotrophin secretagogue through its V1b receptor. VP seems to have special importance under prolonged stress conditions, which are known to be strong predictive factor of depressive disorder and can induce depressive-like symptoms. Preclinical and clinical data summarized in this review underline the importance of VP in the development of anxiety- and depressive-like symptoms. Orally active nonpeptiderg V1b antagonists were developed and seemed to have effective anxiolytic and antidepressant profile in preclinical studies, which was not fully confirmed by clinical observations. It seems that V1a receptors on special brain areas could have same importance. Taken together current knowledge strongly implies an importance of vasopressinergic regulation in affective disorders and consider VP as endogenous anxiogenic/depressogenic substance. However, wide range of side effects could develop as a result of an intervention on the VP system; therefore there is a need for area-specific targeting of VP receptors (e.g. with modified nanoparticles)