Three main hypotheses guided the current study: (1) intranasal oxytocin at a high dose would be more beneficial compared to placebo in improving schizophrenia patients’ prosocial behavior and psychopathology; (2) social skills training would be more beneficial compared to supportive psychotherapy; (3) the combined effects of intranasal oxytocin together with the social skills training will be synergetic and will exceed the effects of each intervention on its own in improving prosocial behavior and negative symptoms. Here, OXT is linked to schizophrenia.