Study sponsor was acquired by another company.

The present study proposes to evaluate the potential cognitive enhancing effects of GLYX-13, an NMDAR partial agonist, among a group of healthy adults and those with psychiatric illness on a series of functional magnetic resonance imaging (fMRI) learning and memory tasks.

In a single blind randomized parallel group design, we will evaluate the whether a single dose of GLYX-13 vs. placebo increases cognitive performance on tasks of learning, declarative memory, and working memory, and associated task-related increases in blood oxygen level-dependent (BOLD) activation in hippocampus and dorsolateral prefrontal cortex, respectively. Positive findings will provide biomarker evidence for GLYX-13 effects on neural systems underlying these cognitive processes.

Inclusion Criteria:

For all Individuals

• Male and female subjects
• Ages 18 - 40 years
• General intellectual abilities falling broadly within the average range (estimated intelligence quotient (IQ) between 80 - 119)
• Sufficient ability to understand study requirements and provide written informed consent

For Patients

-Diagnosis of Schizophrenia or Schizoaffective Disorder

Exclusion Criteria:

For all individuals:

• History of neurologic disorder or systemic medical condition that may interfere with central nervous system function
• History of seizures
• History of heard injury with loss of consciousness or concussion
• Positive screen for drugs of abuse: cocaine, marijuana, phencyclidine, ketamine, opioid, or other agent that is being abused in the opinion of the investigator
• Females who are currently pregnant or plan to become pregnant during the study period
• History of allergy, sensitivity, or intolerance to N-methyl-D-Aspartate receptor (NMDAR) ligands including ketamine, dextromethorphan, memantine, methadone, dextropropoxyphene, or ketobemidone
• History of any ferromagnetic object in the body
• Presence of any medical device or implant for which MRI is contraindicated including cardiac pacemaker, aneurysm clip, cochlear implant, copper intrauterine device (IUD), neurostimulator, or any other device deemed unsafe
• Bullet or shrapnel in body
• Metallic braces or permanent retainer
• Significant claustrophobia

For Healthy Individuals

• Personal history of any Axis I disorder according to the Structured Clinical Interview for the DSM-5 (SCID-5) criteria
• History of treatment with antidepressant, antipsychotic, stimulant,sedative/ hypnotic, mood stabilizing, or anticholinergic medications or lithium
• History among first-degree family members of any psychotic illness or major mood disorder (e.g., major depressive disorder, recurrent; bipolar I or II disorder)

For Patients

• Treatment with Clozaril
• Change in medication within 1 month
• Hospitalization within 1 month