The goal of this clinical trial is to examine if iTBS applied to the DMPFC improves social cognitive performance compared to sham stimulation in people diagnosed with schizophrenia, schizoaffective disorder, schizophreniform disorder, or psychotic disorder not otherwise specified. The main objectives of this trial are:

• Compare changes in social cognitive performance between the active vs. sham treatment groups
• Compare changes in social cognitive network functional connectivity between the active vs. sham treatment groups

Each participant will receive iTBS (active or sham) five days per week for four consecutive weeks. Functional magnetic resonance imaging (fMRI) scans, clinical assessments, and cognitive tests will be performed at pre-treatment, post-treatment, and 6 months after the completion of treatment.

Inclusion Criteria:

1. Age 18-39 years.
2. DSM-5 diagnosis of schizophrenia, schizoaffective disorder, schizophreniform disorder, or psychotic disorder not otherwise specified (documented by SCID-5).
3. Prescription of antipsychotic medication for at least 60 days and constant dose for 30 days prior to study entry (either first- or second-generation antipsychotics permitted).
4. Able to participate in the informed consent process and provide voluntary informed consent.

Exclusion Criteria:

1. A history of a DSM-5 substance use disorder (other than cannabis, caffeine, or tobacco) within the past six months; or a positive baseline urine drug screen. Only participants meeting for moderate to severe cannabis use disorder will be excluded.
2. Type 1 diabetes mellitus (i.e., insulin-dependent diabetes mellitus with onset < 35 years of age and/or diabetes mellitus that has been complicated by a prior documented episode of ketoacidosis)
3. Acute or unstable medical illness (e.g., delirium, cancer, uncontrolled diabetes, decompensated cardiac, hepatic, renal or pulmonary disease, stroke, or myocardial infarction), whose pathology or treatment could alter the presentation or treatment of schizophrenia or significantly increase the risk associated with the proposed treatment protocol
4. Neurological disease associated with extrapyramidal signs and symptoms (e.g., Parkinson's disease); epilepsy, if the person has had one or more grand mal seizures in the past 18 months; history or physical signs of stroke; any diagnosis of a Central Nervous System (CNS) disorder
5. Requires a benzodiazepine with a dose equivalent to lorazepam 2 mg/day or higher due to the potential of these medications to limit the efficacy of iTBS
6. Suspected DSM-5 intellectual disability based upon clinical interview and psychosocial history
7. Prior Psychosurgery
8. Presence of MRI contraindications (e.g., pacemakers)
9. Pregnancy
10. TMS treatment in the past three months