Transcranial Photobiomodulation (tPBM) in Alzheimer's Disease Study

Inclusion Criteria: * Signed and dated informed consent form (either by subject or LAR) * Willingness and ability to comply with all study procedures * Age 55 to 89 years, inclusive * Clinical diagnosis of Mild Cognitive Impairment or mild dementia (CDR Global = 0-1; MoCA 16-25) due to probable Alzheimer's disease diagnosis * Ability to attend in-person sessions at Cedars-Sinai and adhere to weekly visits * Stable dose of Alzheimer's disease medications (e.g., donepezil, rivastigmine, memantine, galantamine) for at least 4 weeks prior to enrollment, if applicable Exclusion Criteria: * Presence of significant neurological conditions other than AD (e.g., epilepsy, Parkinson, etc.) * History of Seizures * If patient holds neuroimaging showing space-occupying lesions * If patient holds imaging with Fazekas greater than or equal to 3, more than 2 lacunar infarcts, and/or more than 5 microhemorrhages * Current pregnancy or lactation (although unlikely in this population) * Participation in another clinical trial or investigational drug within the past 30 days * Active use of illicit substances or non-prescribed psychoactive drugs within the past 30 days. * Severe dementia due to Alzheimer's disease or another etiology * Physical or mental impairment that prevents the participant from complying with the cognitive testing battery.