The role of intranasal oxytocin in anxiety and depressive disorders: a systematic review of randomized controlled trials
Francesca De Cagna 1*, Laura Fusar-Poli 1, 2, Stefano Damiani 1, Matteo Rocchetti 1, Gianluca Giovanna 1, Alessia Mori 1, Pierluigi Politi 1, Natascia Brondino 1
1Department of Brain and Behavioral Sciences, University of Pavia, via Bassi 21, 27100, Pavia, Italy, 2Department of Clinical and Experimental Medicine, Psychiatry Unit, University of Catania, via Santa Sofia 78, 95123, Catania, Italy
Received: May 10, 2018; Revised: August 15, 2018; Accepted: August 16, 2018; Published online: August 16, 2018.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Several studies have demonstrated the neuromodulating function of oxytocin (OT) in response to anxiogenic stimuli as well as its potential role in the pathogenesis of depression. Consequently, intranasal-OT (IN-OT) has been proposed as a potential treatment of anxiety and depressive disorders. The present systematic review aimed to summarize the randomized controlled trials (RCTs) evaluating the effect of IN-OT on anxiety and depressive symptoms.
Overall, 15 studies were included, involving patients with social anxiety disorders (SAD; 7 studies), arachnophobia (1), major depression (MDD; 3) or post-natal depression (PND; 4), and mainly evaluating single-dose administrations of IN-OT.
Results showed no significant effects on core symptomatology. Five crossover studies included fMRI investigation: one trial showed reduced amygdala hyperreactivity after IN-OT in subjects with anxiety, while another one showed enhanced connectivity between amygdala and bilateral insula and middle cingulate gyrus after IN-OT in patients but not in healthy controls. More studies are needed to confirm these results. In conclusion, up to date, evidence regarding the potential utility of IN-OT in treating anxiety and depression is still inconclusive. Further RCTs with larger samples and long-term administration of IN-OT are needed to better elucidate its potential efficacy alone or in association with standard care.
Keywords: oxytocin, depression, anxiety, social cognition, fMRI