Psychological stress of exposure to uncontrollable noise increases plasma oxytocin in high emotionality women.

Oxytocin (OT), arginine-vasopressin (AVP), memory, and mood changes were measured in relation to the psychological stress of exposure to uncontrollable noise (UN), with the physical stress of exposure to the identical, but controllable, noise (CN) as a comparison. Four experiments were performed. In the first, UN but not CN resulted in OT increases in women but not in men; neither treatment altered plasma AVP. No significant changes were detected in the second study, but in the third women again showed an OT response to UN. In both the first and third study the OT response was found in only a proportion of the women exposed to UN. This result was analysed further in the fourth study, in which the stress-induced OT response occurred in high, but not in low, emotionality women. In the fourth, but not in the third, study there was an indication that OT increases may be associated with a general impairment of memory. There was no evidence to support an enhancement of negative memories after exposure to UN. Exposure to noise generally produced a worsening of mood, with no consistent differences between the UN and CN conditions. This is the first report of an OT response to psychological stress in human subjects.