**9.2. AVP and human maternal behavior**

Studies of multiparous humans report that maternal sensitivity is associated with the AVP V1a receptor gene. Mothers with 2 copies of the long RS3 alleles were less sensitive than mothers with one or zero copies of the long allele, and this association was most prevalent in mothers exposed to high maternal adversity [204]. A valid question is how this polymorphism affects affiliation in females, as in the Walum et al. 2008 study. Exposure to maternal neglect is associated with depressed urinary AVP levels in children [205]. The effects were persistent despite being in a stable environment for three years following the maternal neglect. It was concluded that social deprivation inhibits the long-term development of the central AVP system, and this effect may be involved in the etiology of neglect associated mood disorders.
