Inclusion Criteria:
* Age 18-65
* English proficiency sufficient for informed consent, questionnaires/tasks, and treatment
* Primary diagnosis of one of the following: major depressive disorder (MDD), obsessive-compulsive disorder (OCD), generalized anxiety disorder (GAD), or schizophrenia (determined by focal assessment using the Structured Clinical Interview for DSM-5)
* ≥20 on the Beck Depression Inventory for patients with MDD
* ≥16 on the Beck Anxiety Inventory for patients with GAD
* ≥16 on the Yale-Brown Obsessive-Compulsive Scale for patients with OCD
* ≥58 on the Positive and Negative Symptom Scale for patients with schizophrenia
* Stable psychotropic medication regimen, or remain medication free, for 4 weeks prior to treatment (Medication changes during study enrollment period will be tracked for post hoc analysis).
* Primary clinician (e.g. psychiatrist, therapist, psychologist, APRN, PA, etc.) responsible for psychiatric care before, during, and after the trial
Exclusion Criteria:
* Active pregnancy as determined by a urine pregnancy test
* Cluster B personality disorders (antisocial personality disorder, borderline personality disorder, histrionic personality disorder, narcissistic personality disorder)
* PTSD with active, clinically significant symptoms, as determined by clinician
* Diagnosis of Schizoaffective Disorder, Bipolar Type
* Recent (within 4 weeks) or concurrent use of rapid-acting antidepressant agent (ketamine/esketamine/ECT)
* Ferromagnetic metallic implant that would contraindicate receiving TMS or obtaining MRI
* Any other TMS or MRI safety concerns identified by the clinician
* Receiving or planning to receive other TMS treatments during course of participation
* History of:
* Neurosurgical intervention for mental illness
* Moderate to severe autism spectrum disorder
* Intellectual disability
* Severe cognitive impairment
* Significant neurological illness (e.g., dementia, Parkinson's, Huntington's, brain tumor, seizure disorder, subdural hematoma, multiple sclerosis)
* Untreated or insufficiently treated endocrine disorder
* Eating disorders
* Treatment with investigational drug or intervention during the study period
* Current evidence of:
* Mania or hypomania
* Active suicidal ideation or a suicide attempt within the past year
* Contraindications to either TMS or MRI (e.g., metallic implants, etc.).
* Current moderate or severe substance use disorder or demonstrating signs of acute substance withdrawal
* Significantly increased seizure risk as determined by a clinician
* For participants with schizophrenia:
* Evidence of impaired capacity to consent, e.g. impaired insight into illness, as deemed by a licensed psychiatrist or psychologist on the study team
* Hospitalization with psychosis in the past 6 months
* Positive urine drug screen for illicit substances
* Existing tinnitus (ringing in the ears)
* Any other condition deemed by the PI to interfere with the study or increase risk to the participant
