Galantamine and Memantine Combination for Cognitive Impairments in Schizophrenia

Inclusion Criteria: * Be male or female aged 18 to 55 years (inclusive). * Have a DSM-5 diagnosis of schizophrenia or schizoaffective disorder confirmed by medical records. Duration of illness must be ≥ 1year. * Be clinically stable for at least two months (i.e., has no more than a "moderately severe" severity rating on the following BPRS items: hallucination, unusual thought content and conceptual disorganization. * Have not had a psychiatric hospitalization in the two months prior to screening. * Be taking any 1st generation antipsychotic prescribed in the absence of a concomitant anticholinergic or 2nd generation antipsychotic and minimal extrapyramidal symptoms * Have a Simpson-Angus Score (SAS) \< 6 * Be on current medication regimen for at least six weeks before screening at stable dose and frequency for at least 30 days before screening. * Be in good general health and expected to complete the clinical study as designed. * Subjects of childbearing potential must agree to use two forms of non-hormonal contraception (dual contraception) consistently during the screening and treatment periods of the trial, and for 30 days after the final dose of the study medications. * Females of child-bearing potential must have a negative urine pregnancy test at baseline. This may also be done at subsequent visits if subject reports possibility of pregnancy. * Have a negative urine drug screen at screening. This may be repeated at the discretion of the primary investigator. * Have adequate hearing, vision, and language skills to perform the procedures specified in the protocol. * Be capable of providing informed consent and have voluntarily provided informed consent. Exclusion Criteria: * Have an active, clinically significant unstable medical condition with 30 days prior to screening. * Have dementia. * Are pregnant, breastfeeding, or planning to become pregnant * Are taking or thinking about taking oral contraceptives or an injectable contraceptive. * Are taking benztropine at a dose greater than 2 mg daily. * Have a history of Pervasive Development Disorder. * Have a history of significant head injury/trauma (defined by one of more of the following: loss of consciousness for more than one hour; recurring seizures resulting from the head injury; and/or clear cognitive sequelae of the injury requiring cognitive rehabilitation.) * Have an allergy to anticholinesterase medications (galantamine, rivastigimine, donepezil) and memantine * Have a DSM-5 diagnosis of alcohol and/or substance use disorder (other than caffeine and tobacco) within the last 6 months. * Are taking a restricted medication: Amitriptyline, Doxepin, Imipramine, Flexeril, Clozapine, and/or cortisol (any oral, injectable, or topical steroid medication) * Have a history of seizures excluding a childhood febrile seizure * Have received ECT within the last three months prior to screening. * Have participated in a clinical trial of any other psychotropic medication within last two months prior to screening. * Have a "severe" or "extremely severe" severity rating on the BPRS items: hallucination or unusual thought content. * Have more than a "moderate" severity rating on the BPRS item conceptual disorganization . * Are currently taking 3 or more antipsychotic medications.