Bipolar Transcranial Alternating Current Stimulation (tACS)

Inclusion Criteria:

• Confirmed diagnosis of BD based on Diagnostic and Statistical Manual of MentalDisorders Fourth Edition (DSM-IV) criteria being met from previous enrollment in thePrechter Bipolar Longitudinal Study

• This study will select BD patients that scored above published norms (upper 50thpercentile) on the NEO-PI impulsivity facet to ensure that the recruited patientsexhibit the network dysfunction targeted by the tACS paradigm and therefore have thepotential to benefit from this neuromodulation technique.

• Patients must be on a stable dose of medication for two weeks prior to Sessions 2and 3.

Exclusion Criteria:

• Significant neurological abnormalities, such as seizure disorder, mass lesions, etc.

• Known Mendelian disorder

• Active problematic substance use in the past 30 days (as determined by the SubstanceUse Disorder module of SCID)

• Evidence of suicidal intentions or behaviors in the past month, as judged byaffirmative responses to question number 4 or number 5 on the Columbia SuicideSeverity Rating Scale (CSSRS) or report of suicidal behaviors in the last 6 months

• Pregnant or trying to become pregnant, or currently lactating.