The effects of adjunctive intranasal oxytocin in patients with schizophrenia

ABSTRACT

Objectives: Both human and animal studies have suggested that oxytocin may have therapeutic potential in the treatment of schizophrenia. We evaluated the effects of intranasal oxytocin on cognition and its predictive factors in Japanese patients with schizophrenia.

Methods: Subjects were 16 chronic schizophrenia patients who underwent intranasal oxytocin treatment for 3 months and were assessed for changes in severity of clinical symptoms and cognitions. Fifteen of the 16 subjects underwent 3-Tesla magnetic resonance imaging.

Results: Oxytocin significantly reduced scores on the positive and negative syndrome scale, especially on the negative symptoms. As for cognition, there was an improvement of the verbal fluency. Furthermore, the change of the negative score in positive and negative syndrome scale showed a negative correlation with the gray matter volumes of the right insula and left cingulate cortex.

Conclusions: Our results indicate that daily administration of intranasal oxytocin may be effective for ameliorating clinical symptoms and cognitive functions in chronic schizophrenia patients, and this improvement may be related to the gray matter volume of the right insula and left cingulate cortex.

KEYWORDS:

• Antipsychotics
• cognition
• magnetic resonance imaging
• oxytocin
• schizophrenia

Acknowledgments

The authors were involved in the study design and data collection. The authors participated in the data analysis, data interpretation, and the writing of the article. The authors had full access to all data and had final responsibility for the decision to submit for publication.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This study was supported by Health and Labor Sciences Research Grants (to H.K.), a Grant-in-Aid for Young Scientists (B) (26861035) from the Japan Society for the Promotion of Science (M.O.), an Intramural Research Grant (24-11) for Neurological and Psychiatric Disorders of NCNP (M.O. and H.K.), and funds from the SENSHIN Medical Research Foundation (M.O.), and by the project ‘Understanding of Molecular and Environmental Bases for Brain Health’ carried out under the Strategic Research Program for Brain Sciences by the Ministry of Education, Culture, Sports, Science and Technology of Japan (H.K., T.Y.). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.