Dr Simone Meddle of the University's Centre for Integrated Physiology, explained: "Childbirth is a powerful cause of psychiatric disorders in women; perhaps more than any other lifetime event, it causes significant changes in a woman's body and feelings. We tend to assume that motherhood is joyful and rewarding, but in some women these brain changes can cause serious and long lasting effects on her emotional state: in extreme cases the woman may harm her child.
"It is estimated that in Britain at least 10% of women from all ages and backgrounds become apprehensive and unhappy following the birth of their child. Effective drug treatment of this condition requires a better understanding of the hormones that influence her brain and cause this behaviour."
Scientists suspect that hormone signals within the brain are involved in behavioural change. Female rats are not normally aggressive, but following birth they become fiercely defensive of their pups against intruders. Sometimes, this aggression causes the mother rat to turn on her own babies and harm them. The scientists plan to study the hormone vasopressin which is known to control aggressive behaviour in male rats. Results of these studies will form a model for the study of human mothers.