Light at the end of the tunnel: bright light therapy may boost opioid recovery

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * All Participants * Between 18 and 60 years old * Fluent in English * Able to provide written informed consent OUD * DSM-5 diagnosis of an OUD. * ≥12 months of lifetime opioid use * Positive on urine drug screen for buprenorphine or methadone * Receiving opioid agonist therapy for OUD (e.g., methadone or buprenorphine) with a stable dose for the past month. Must have been stabilized on OMT medication, since the increasing of doses during induction phase might interfere with outcomes and unstable patients might experience strong withdrawal symptoms in the morning which makes them unsuitable for a home-based BLT. * Other substance use was not exclusionary, but opioids were identified as primary. Exclusion Criteria: All Participants * Head trauma with loss of consciousness for more than 30 minutes as determined by medical history. * history of seizures/epilepsy. * Pregnant and/or currently breast-feeding. * Presence of ferromagnetic objects in the body that are contraindicated for MRI or fear of enclosed spaces. * Eye disease including disease of the anterior and posterior segment of the eye, cataracts, retinopathy, glaucoma, amblyopia, scotoma, color or night blindness, corneal pathologies, macular degeneration, or retinitis pigmentosa reported by history or identified by eye exam * History of eye surgery * Chronic migraine triggered by bright light * worked night shift or traveled across\>2 time zones in the past month OUD * diagnosis of substance use disorder other than for opioids that was deemed to be primary * lifetime diagnosis of schizophrenia, bipolar disorder, or suicidality. * History of light treatment * Unstable dose of psychiatric medication (hypnotics, sleep aids, and antidepressants must be stable for 30 days before and during the study) HC * Current or past DSM-IV or DSM-5 diagnosis of a psychiatric disorder including substance use disorder (except for nicotine/caffeine). * Current DSM-5 sleep-wake disorders including insomnia disorder