D. Feifel
Feb 1, 2011
Citations
0
Influential Citations
26
Citations
Journal
Expert Review of Neurotherapeutics
Abstract
To the extent that chemicals can be fashionable, oxytocin is perhaps the most fashionable chemical in neuroscience today. This nine amino acid peptide is appearing with regular frequency as the subject of scientific articles in the most prestigious journals in the field. The popular media have been quick to join the bandwagon, crafting stories that sensationally extoll oxytocin’s pro-social properties and dubbing it the ‘love hormone’ and the ‘cuddle hormone’. Given the strong evidence of oxy tocin’s ability to enhance social cognition, there has been much speculation about its potential role in the etiology and treatment of psychiatric disorders. Autism spectrum disorders and social phobia have garnered the most attention in this regard for obvious reasons. Less obvious is oxytocin’s possible role in schizophrenia. Over a decade ago my laboratory conducted a preclinical proofof-concept study to test our hypothesis that oxytocin exhibits antipsychotic-like effects. This hypothesis was based mostly on evidence that oxytocin regulated central dopamine. That study, conducted in rats, revealed that systemically administered oxytocin, similar to most atypical antipsychotics, reversed prepulse inhibition deficits induced by amphetamine and the phencyclidine analog, MK801 [1]. Those antipsychotic-like results were surprising, even to my team, since oxytocin has a poor ability to penetrate the BBB. Since then, a number of investigators have reported finding antipsychotic-like effects attributed to endogenous oxytocin or systemically administered oxytocin in several different animal models relevant to schizophrenia [2,3]. The accumulation of those promising preclinical findings, as well as numerous studies demonstrating that intranasal oxytocin enhances trust and other pro-social inclinations [4,5], have recently spurred the initiation of several small clinical trials to test the therapeutic potential of oxy tocin in schizophrenia. Our group recently completed the first such proof-ofconcept clinical trial: a double-blinded, placebo-controlled crossover design enrolling schizophrenia patients who were highly symptomatic despite receiving therapeutic doses of an atypical antipsychotic. Intranasal oxytocin (40 international units twice a day) administered as an adjunct to the subjects’ antipsychotic for 3 weeks improved positive and negative symptoms significantly more than placebo did [6]. Recently, another group of investigators at the University of North Carolina (UNC; NC, USA), led by Cort Pedersen reported preliminary results from their own study of adjunctive intranasal oxytocin in schizophrenia patients [7]. They found that 2 weeks of daily intranasal oxytocin significantly reduced schizophrenia symptoms, adding support to the notion that oxytocin has therapeutic potential for the core symptoms of schizophrenia. David Feifel