Transcranial Photobiomodulation for Executive Function in Bipolar Disorder (TPEB)

Transcranial light therapy, or transcranial photobiomodulation (tPBM), is a treatment that stimulates the brain by applying near-infrared light to the forehead. Transcranial light therapy has been found to promote brain metabolism, which may help improve executive function in people with bipolar disorder. The research team proposes a novel approach to treating bipolar disorder by using transcranial light therapy.

This study involves a virtual screening visit, 7 in-office visits, and a virtual check-in call with a clinician. Participation will last approximately 3 weeks in total. Participants will attend a baseline visit during which they will complete mood questionnaires and a gambling task. Participants will then receive five treatments of transcranial light therapy over one week. The first and last of these treatments will be administered while the participant is in an MRI scanner. At the first visit, participants will also receive a "sham" tPBM treatment, meaning that the device will simulate real treatment, but will not actually apply the near-infrared light. The check-in call will occur approximately 2-3 days after the final treatment visit. This will be a brief call with a study clinician to check-in on the participant's mental and physical health. The follow up visit will occur approximately one week after the final visit. Subjects will be asked to complete mood questionnaires and/or gambling tasks during the first and fifth treatment visits, as well as at the follow up visit.

During the first treatment visit, participants will receive one active tPBM treatment and one sham tPBM treatment. Participants will be blinded as to the order in which they receive these treatments.

Transcranial light therapy penetrates the skin and brain using light energy; this makes transcranial light therapy noninvasive. Transcranial light therapy may activate under-stimulated brain regions.

Change in cerebral blood flow (CBF) during a single session of tPBM (Day 1) and change in cerebral blood flow from baseline to final day of treatment (Day 5)

Inclusion Criteria: Adults between the ages of 18 and 65 Diagnosis of bipolar disorder Currently experiencing symptoms of impulsivity Exclusion Criteria: Currently in depressive, manic, or mixed episode Currently psychotic Judged to be at serious and imminent suicidal risk Currently in alcohol or substance use disorder (meeting criteria in the past 12 months) Unstable medical conditions Inability to consent or to complete study procedures Failure to meet standard MRI safety requirements (e.g. claustrophobia, non-removable piercings, implanted medical devices, other non-removable metals) Changes in medications or use of augmentative devices and other interventions in the 2 weeks prior to the study Participation in other clinical research trials that may influence primary outcomes or adherence to the proposed study Current pregnancy.