Investigating the application of transcranial infrared laser stimulation in individuals with bipolar disorder.

Individuals with bipolar disorder have progressive cognitive decline with repeated mood episodes. This cognitive dysfunction is associated with decreased prefrontal cortex oxygen metabolism, involving cellular respiration in mitochondria. Transcranial infrared laser stimulation (TILS) of the prefrontal cortex uses a near-infrared wavelength of invisible light that penetrates the cortex and improves the ability of mitochondria to use oxygen in the brain. This new technology has been proven safe and is a non-pharmacologic, portable, convenient, and cost-effective form of modulating brain oxygenation using low-level infrared light. This treatment has shown great potential by improving cognitive and mood functioning in controlled human studies by photoactivation of the terminal enzyme in the mitochondrial respiratory chain called cytochrome oxidase (CCO). This mechanism results in unique functional benefits for neurons by stimulating oxygen metabolism. Since bipolar disorder may involve mitochondrial metabolic abnormalities, TILS is a potentially promising intervention. The investigators propose a study among individuals with bipolar disorder in order to 1) elucidate the physiological mechanisms of TILS using non-invasive neuroimaging methods (fNIRS, fMRI and ASL-MRI), and 2) investigate the benefits on people's cognitive functions and symptoms after TILS.

This is open label clinical trial with a single group assignment to treatment for individuals with bipolar disorder. The investigators will investigate if transcranial infrared laser stimulation (TILS) can upregulate brain activity and improve cognition.

Inclusion

1. Able to read, speak, and understand English.
2. DSM-5 primary diagnosis of Bipolar Disorder type 1 or 2, by structured clinical interview (SCID-5).
3. Montgomery-Asberg Depression Rating Scale score ≤ 12.
4. Young Mania Rating Scale score ≤ 7.
5. On at least one anti-mania agent at a therapeutic dose for 6 weeks.
6. On stable doses of any standing psychotropics for 6 weeks.
7. Any standing benzodiazepine to a maximum dose equivalent to 22.5 mg oxazepam or 7.5 mg diazepam per day.

Exclusion Criteria:

1. Unable/unwilling to give informed consent.
2. Diagnosed with current primary psychotic disorder (rather than bipolar disorder).
3. Diagnosed with current manic/hypomanic or depressive episode.
4. Moderate to severe substance use disorder within the past 6 months (except nicotine, caffeine, cannabis).
5. Clinically defined major neurological disorder; including, but not limited to, seizure disorder and history of loss of consciousness due to head injury for greater than 10 minutes, or documented evidence of brain injury.
6. Active suicidal intent/plan as detected on screening assessments, or in the investigator's opinion is likely to attempt suicide within the next 6 months.
7. Clinically significant unstable medical condition.
8. If female: pregnant, not using medically acceptable birth control, or currently breastfeeding.
9. Other conditions judged by the investigator that could prevent the participant from completing the study (such as but not limited to, significant physical disability (e.g., hearing/visual deficits) to perform a neutral memory task and/or neuropsychological test battery).