Intranasal oxytocin effects on social cognition: a critique.
The last decade has seen a large number of published findings supporting the hypothesis that intranasally delivered oxytocin (OT) can enhance the processing of social stimuli and regulate social emotion-related behaviors such as trust, memory, fidelity, and anxiety. The use of nasal spray for administering OT in behavioral research has become a standard method, but many questions still exist regarding its action. OT is a peptide that cannot cross the blood-brain barrier, and it has yet to be shown that it does indeed reach the brain when delivered intranasally. Given the evidence, it seems highly likely that OT does affect behavior when delivered as a nasal spray. These effects may be driven by at least three possible mechanisms. First, the intranasally delivered OT may diffuse directly into the CNS where it directly engages OT receptors. Second, the intranasally delivered OT may trigger increased central release via an indirect peripheral mechanism. And third, the indirect peripheral effects may directly lead to behavioral effects via some mechanism other than increased central release. Although intranasally delivered OT likely affects behavior, there are conflicting reports as to the exact nature of those behavioral changes: some studies suggest that OT effects are not always "pro-social" and others suggest effects on social behaviors are due to a more general anxiolytic effect. In this critique, we draw from work in healthy human populations and the animal literature to review the mechanistic aspects of intranasal OT delivery, and to discuss intranasal OT effects on social cognition and behavior. We conclude that future work should control carefully for anxiolytic and gender effects, which could underlie inconsistencies in the existing literature. This article is part of a Special Issue entitled Oxytocin and Social Behav.
School of Psychology, University of Sussex, Brighton, East Sussex BN1 9QG, United Kingdom.
Simon L
SL
Evans
Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; Department of Neuropsychology, University of Turin, Turin, Italy.
Olga
O
Dal Monte
Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
Pamela
P
Noble
Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA. Electronic address: bruno.averbeck@nih.gov.
Bruno B
BB
Averbeck
D000281:Administration, Intranasal; D000818:Animals; D003071:Cognition / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D010121:Oxytocin / Q000008:administration & dosage*; D011619:Psychotropic Drugs / Q000008:administration & dosage*; D012919:Social Behavior
D011619:Psychotropic Drugs; D010121:Oxytocin
Anxiety; CSF; Intranasal administration; Oxytocin; Pro-social neuropeptide; Social cognition; Social stimuli