Oxytocin plays an important role in human attachment, trust, social perception, memory, and fear regulation. Evidence suggests that CD38, a regulator of oxytocin release, may also be critical in these processes. The purpose of this study was to investigate the predictors of plasma oxytocin level measured after a task requiring intimate trust (secret sharing), modeling psychotherapeutic processes, and a neutral social interaction. Results revealed that peripheral CD38 expression positively predicted both trust-related and trust-unrelated oxytocin levels. In addition, habituation of arousal, as measured by skin conductance response, and attachment anxiety also emerged as predictors of oxytocin level in the trust-related condition. These results suggest that CD38 plays a general role in oxytocin secretion, whereas habituation of arousal and attachment anxiety are specifically related to situations involving intimate trust
