Secretin for refractory schizophrenia.

In preliminary uncontrolled studies, intravenous injection of the gastrointestinal peptide secretin produced improvements in the symptoms of autism. Because of the phenotypic overlap between autism and some aspects of schizophrenia, we performed a pilot study of secretin for treatment refractory schizophrenia. Twenty-two patients were randomized to a single intravenous dose of porcine secretin or placebo. Patients were evaluated with the Positive and Negative Symptom Scale for Schizophrenia (PANSS) and the Clinical Global Impression Scale (CGI) at baseline, 2 days after secretin infusion and weekly for 4 weeks. There were no statistically significant differences between drug- and placebo-treated patients with repeated measures analysis of variance (ANOVA). However, several patients treated with secretin experienced clinically meaningful, but transient, reductions in symptoms and a greater percentage of patients treated with secretin were rated as improved with the CGI. Further study of brain hypocretins and molecules affecting this system are warranted in schizophrenia.