Could ditching a common drug sharpen the mind in schizophrenia?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Primary DSM-defined diagnosis of schizophrenia, schizoaffective disorder, or unspecified psychotic disorder, verified by the Structured Clinical Interview for DSM-5 (SCID). 2. Prescription of benztropine or trihexyphenidyl for at least 6 months 3. Age 35-70 years. 4. ACBS score \>= 3. 5. Mild or absent extrapyramidal symptoms (Determined by clinical pharmacists and prescribers). 6. Competency and willingness to sign informed consent. Inclusion criteria for the healthy control group: 1. Age 40-70 years. 2. Competency and willingness to sign informed consent. Exclusion Criteria: 1. Serious anticholinergic side-effects (e.g., fever, blurred vision) indicative of a need for immediate removal of anticholinergics, 2. Serious neurologic or medical condition/treatment that impacts the brain and Neurodegenerative conditions such as Parkinson's, dementia, etc.; autoimmune conditions such as Multiple Sclerosis (MS) and lupus; as well as traumatic brain injury (TBI). 3. Significant risk of suicidal or homicidal behavior. 4. Cognitive or language limitations, or any other factor that would preclude subjects providing informed consent. 5. Contraindications for MR imaging (e.g., a pacemaker). 6. Current SCID-verified substance use disorder will be excluded to avoid the confounding impact of significant substance use comorbidity. Participants with a history of substance use disorder that is in early or full remission will be eligible, to enhance generalizability. 7. Patients concurrently treated with electroconvulsive therapy will be excluded because of its effects on cognition. Exclusion criteria for Healthy Control (HC) subjects: 1. No history of psychotic illness and no active Axis I disorder as determined by clinical interview using the SCID-NP. 2. Score greater than 1 on the ACB scale. 3. MR imaging contraindications. 4. Neurologic conditions, any serious non-psychiatric disorder that could affect brain functioning, or intellectual disability. 5. HC with family history of psychosis will be excluded, as such individuals show subtle, but significant cognitive and neurobiological abnormalities. 6. Individuals currently taking anticholinergic medications for reasons other than SSD.