Intermittent Theta Burst Stimulation (iTBS) for Emotion Regulation in Bipolar Disorder

Inclusion Criteria: 1. Individuals of all genders 2. ages 24-65 3. Diagnostic Statistical Manual (DSM-5) defined diagnosis of bipolar I or II disorder (BD); assessed using the Mini-International Neuropsychiatric Interview (M.I.N.I.) version 7.0.2. 4. Current depressive episode, assessed using the Montgomery-Asberg Depression Rating Scale (MADRS) score ≥20, 5. Ability to provide informed consent and verifiable contact information, including current psychiatric treatment provider 6. Stable medication regimen for at least one month, which must include a mood stabilizer Exclusion Criteria: 1. current mania/hypomania assessed by the Young Mania Rating Scale (YMRS \> 12) 2. rapid-cycling bipolar illness, defined as \>4 episodes per year, indicating increased risk of switch to mania 3. current active suicidality (suicidal ideation with intent or plan), as assessed by a score \>4 on the MADRS item #10 4. current substance use disorder for the past 6 months; substance use disorder in remission permitted 5. history of psychosis 6. dementia or other major neurological disorders, as assessed by a Mini-Mental State Exam (MMSE) score \<24 and Montreal Cognitive Assessment (MOCA) score \<26 7. medical illness or non-psychiatric medical treatment that would likely interfere with study participation 8. contraindications for magnetic resonance imaging (MRI) or transcranial magnetic stimulation (TMS), including the presence of metallic implants that would interfere with safety (i.e. cardiac pacemaker, metal plates, non-removable body piercings, etc.), history of seizure disorder, history of head trauma 9. a clinical course of a neuromodulatory therapy (e.g. transcranial magnetic stimulation, transcranial direct current stimulation, electroconvulsive therapy) within the past 6 months 10. current use of benzodiazepines, which can interfere with iTBS stimulation 11. current pregnancy, to limit potential risks to an unborn child Other: Given that \>86% of BD patients experience lifetime comorbid anxiety, co-occurring anxiety disorders will be allowable for inclusion, thus providing a more representative sample of bipolar patients who typically present at our Clinics for treatment. Comorbid anxiety disorders are not a criteria for inclusion or exclusion.