Effects of Transcranial Photobiomodulation in ADHD

The investigators have previously shown that non-invasive methods of brain stimulation such as the administration of transcranial infrared light to the prefrontal cortex (PFC) can result in improvements to cognition and emotion as well as brain oxygenation. This method is called transcranial photobiomodulation (tPBM). The investigators hypothesize that tPBM can improve cognition and brain oxygenation in adults with attention deficit hyperactivity disorder (ADHD). The investigators will investigate the effects of repeated tPBM sessions on cognitive functioning in adults with ADHD. Specifically, the investigators hypothesize that participants that receive tPBM will show improvements in response control, sustained attention, and working memory, as well as improvements in prefrontal hemodynamics and a reduction in ADHD symptoms.