**6. Conclusion**

We hypothesized that OT signaling in the central nervous system may play a significant role in the pathophysiology of ASD based on studies using OT-related knockout mice, effectiveness in social context of OT to healthy subjects, and the results of short-term administration of OT on social impairments in ASD subjects. Long-term clinical trials of OT in ASD subjects are currently in progress. It is difficult to determine how symptoms of social impairment should be assessed in interventions in patients with ASD, although investigation of self-consciousness may provide important insights regarding this issue.
