Effect of Single Dose Intranasal Insulin On Cognitive Function

Effect of Single Dose Intranasal Insulin on Cognitive Function in Patients With Schizophrenia

The purpose of the study is to find out how a small dose of insulin might affect memory, the ability to concentrate, and improve your daily functioning in patients with schizophrenia and schizoaffective disorders. Insulin is not being used to treat diabetes in this study. The investigators propose a single dose, double-blinded, placebo-controlled trial of intranasal insulin in 40 subjects with schizophrenia or schizoaffective disorder to examine insulin's effect on cognition. The specific aims include:

1. Examine the effects of single doses of 40 IU intranasal insulin compared to placebo on cognitive functioning, including attention and memory.
2. Examine whether single dose of intranasal insulin administration will raise serum insulin level and decrease plasma glucose level

Insulin will be delivered through an air spray pump into your nose. The investigators will be comparing one dose of insulin (40 International Units) with placebo, an inactive liquid.

Insulin signaling in the brain is associated with improved cognitive function in both animal and human studies. Intranasal administration of insulin, which is non-invasive and minimizes the risk of hypoglycemia, may represent a new intervention approach with the potential to improve cognition and real life functioning in this patient with schizophrenia.

Inclusion Criteria:

• Age 18-65 years
• Diagnosis of schizophrenia, any subtype or schizoaffective disorder, any subtype
• Male or female
• Stable dose of the current antipsychotic drug for at least one month
• Well established compliance with out-patient treatment per treating clinician's judgement.
• Able to complete the cognitive assessment battery (must be English speaking)

Exclusion Criteria:

• Inability to provide informed consent
• Current substance abuse
• On clozapine or olanzapine
• Psychiatrically unstable per treating clinician's judgement.
• Significant medical illnesses including uncontrolled hypertension, diabetes, seizure disorder, severe cardiovascular, cerebrovascular, pulmonary, or thyroid diseases etc.
• Incapable to complete the cognitive battery assessment.