The Effect of Plasma Osmolality on Brain Glutamate

Inclusion criteria

for healthy controls

• Ages of 21-45 years from all ethnic backgrounds.
• Male or female.
• Written informed consent.
• Female subjects will be studied during the follicular phase of their menstrual cycle.*

Exclusion criteria

for healthy controls

• DSM-IV diagnosis of psychotic, anxiety, mood disorder.
• A history of significant medical/neurological disease. Unstable medical condition based on EKG, vital signs, physical examination and laboratory work-up (CBC with differential, SMA-7, LFTs, TFTs, UA, Utox, Urine pregnancy test, folic acid, B12 levels).
• History of allergies to drugs such as sulfa, multiple adverse drug reactions or known allergy to furosemide.
• Any medication that in the opinion of the PI could interfere with either the safety of the study and/or the outcome measures, such as over the counter cough suppressants or antihistamines.
• History of major psychiatric disorder in first-degree relatives.
• Current substance abuse/dependency determined by plasma and urine toxicology.
• Current treatment with medications with psychotropic effects.
• Current pregnancy, unsatisfactory birth control method report for females.
• Education < 12th grade.
• Non-English speaking.

Inclusion criteria

for patients with schizophrenia

• Ages of 21-45 years from all ethnic backgrounds.
• Male or female.
• Written informed consent.
• DSM-IV diagnosis of schizophrenia or schizoaffective disorder.
• For treated patients: The patient has been on a stable dose of medications (antipsychotics, antidepressants) for the past month and does not require a change of medications or dose adjustment at study entry.
• For untreated patients: Has refused to be treated with medications, maintains regular clinic appointments with the clinicians, and does not pose an imminent danger to himself or others.
• Female subjects will be studied during the follicular phase of their menstrual cycle*.

Exclusion criteria

for patients with schizophrenia

• A history of significant medical/neurological disease. Unstable medical condition based on EKG, vital signs, physical examination and laboratory work-up (CBC with differential, SMA-7, LFTs, TFTs, UA, Utox, Urine pregnancy test, folic acid, B12 levels).
• Orthostatic systolic blood pressure change>20 mmHg or orthostatic pulse change>20 bpm.
• History of polydipsia/hyponatremia**.
• History of allergies to drugs such as sulfa, multiple adverse drug reactions or known allergy to furosemide.
• Any medication that in the opinion of the PI could interfere with either the safety of the study and/or the outcome measures, such as over the counter cough suppressants or antihistamines.
• Current use of lithium (lithium directly interferes with electrolyte balance).
• Currently on clozapine as clozapine may interfere with brain water regulation (Leadbetter and Shutty, 1994).
• Current substance abuse/dependency determined by plasma and urine toxicology.
• Current treatment with benzodiazepines or mood stabilizers (these medications can alter glutamate transmission).
• Current pregnancy, unsatisfactory birth control method report for females.
• IQ < 70 as determined by Wechsler Abbreviated Scale of Intelligence.
• Non-English speaking