Cerebellar Modulation of Cognition in Psychosis

Psychotic disorders including schizophrenia, bipolar disorder, and related illnesses are severe, debilitating, and often fatal. Cognitive impairments in psychosis are among the leading predictors of disability and poor quality of life; despite this, there are no first-line interventions to target these symptoms.

This trial will test the hypothesis that cognitive performance in these disorders is modifiable and specifically that it can be modified non-invasively. Transcranial magnetic stimulation (TMS) is a neuromodulation technique that utilizes magnets to alter brain activity non-invasively. TMS has received FDA approval as a therapeutic intervention for multiple psychiatric disorders. In this study, we will use different forms of TMS to modulate a specific brain circuit and we will measure the outcomes of this circuit manipulation. These outcomes include performance on cognitive tests and also changes to the circuit itself that we can measure using magnetic resonance imaging (MRI).

Inclusion criteria

• Age between 18-55 years
• Diagnosis of a psychotic disorder (i.e. schizophrenia or schizoaffective disorder or bipolar disorder type I)
• Must be able to read, speak and understand English
• Must be judged by study staff to be capable of completing the study procedures
• Participants will be in stable outpatient treatment with no recent (within the past 30 days) hospitalizations or changes in their medication regimens.

Exclusion criteria

• Diagnostic and Statistical Manual 5 diagnosis of moderate substance use disorder within the past month
• Conditions that might result in increased risks of side effects or complications from rTMS or MRI, including:

• Intracranial pathology from a known genetic disorder (e.g., Neurofibromatosis 1, tuberous sclerosis) or from acquired neurologic disease (e.g. stroke, tumor), cerebral palsy, history of severe head injury, or significant dysmorphology;
• History of fainting spells of unknown or undetermined etiology that might constitute seizures
• History of multiple seizures or diagnosis of epilepsy
• Any progressive (e.g., neurodegenerative) neurological disorder such as multiple sclerosis or Parkinson's disease
• Chronic (particularly) uncontrolled medical conditions that may cause a medical emergency in case of a provoked seizure (cardiac malformation, cardiac dysrhythmia, asthma, etc.)
• Metal implants (excluding dental fillings) unless cleared by the responsible covering MD (i.e. MRI compatible joint replacement)
• Pacemaker
• Implanted medication pump
• Vagal nerve stimulator
• Deep brain stimulator or transcutaneous electric nerve stimulation unit
• Ventriculo-peritoneal shunt
• Signs of increased intracranial pressure
• Intracranial lesion
• History of head injury resulting in prolonged loss of consciousness (>15minutes) or neurological sequelae
• Pregnancy: All participants capable of becoming pregnant will be required to have a pregnancy test; any participant who is pregnant will not be enrolled in the study.