This study examined the effect of adjunctive intranasal insulin therapy on psychopathology and cognition in patients with schizophrenia.
Each subject had a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis of schizophrenia or schizoaffective disorder and been on stable antipsychotics for at least 1 month. In an 8-week randomized, double-blind, placebo-controlled study, subjects received either intranasal insulin (40 IU 4 times per day) or placebo. Psychopathology was assessed using the Positive and Negative Syndrome Scale and the Scale for Assessment of Negative Symptoms. A neuropsychological battery was used to assess cognitive performance. The assessment for psychopathology and cognition was conducted at baseline, week 4, and week 8.
A total of 45 subjects were enrolled in the study (21 in the insulin group and 24 in the placebo group). The mixed model analysis showed that there were no significant differences between the 2 groups at week 8 on various psychopathology and cognitive measures (P > 0.1).
Adjunctive therapy with intranasal insulin did not seem to be beneficial in improving schizophrenia symptoms or cognition in the present study. The implications for future studies were discussed.
From the *Psychotic Disorders Program, UMass Memorial Medical Center; †University of Massachusetts Medical School, Worcester; ‡Partners Community Healthcare, Inc, Haverhill; §Schizophrenia Program, Massachusetts General Hospital; ||Harvard Medical School; ¶Department of Medicine, #The Biostatistics Center, Massachusetts General Hospital, Boston; **The Ragon Institute of MGH, MIT, and Harvard, Charlestown; and ††The McLean Hospital, Belmont, MA.
Received March 1, 2012; accepted after revision August 17, 2012.
This study was supported by Grant 5K23MH082098 from the National Institutes of Health (Dr Fan), the NARSAD Young Investigator Award (Dr Fan), Grant M01-RR-01066 and Grant UL1 RR025758-01 from the National Institutes of Health, National Center for Research Resources General Clinical Research Centers Program (MGH Clinical research Center), and an investigator initiated trial grant from Eli Lilly and Company (Dr Fan).
Reprints: Xiaoduo Fan, MD, MPH, MS, Biotech One, Suite 100, 365 Plantation St, Worcester, MA 01605 (e-mail: email@example.com).