Can a flashing light fix teen ADHD sleep troubles?

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

Inclusion Criteria: 1. Age of 14 to 17 years 2. Current DSM-5 diagnosis of attention-deficit/hyperactivity disorder (any type) 3. Self-reported average bedtime of 11:00 pm or later, with difficulty shifting bedtime earlier and difficulty waking up early enough in the morning 4. Evening chronotype (i.e., score ≤ 27 on the Morningness-Eveningness scale for Children) 5. Clinically significant ADHD severity (ADHD-Rating Scale-5 score ≥ 24) 6. Moderate global functioning impairment or worse (Clinical Global Impression-Severity scale score ≥ 4) 7. Attending school (i.e., standard school year or summer school) during study enrollment 8. Fluency in English Exclusion Criteria: 1. Current or lifetime diagnosis of bipolar Disorder, psychosis, autism spectrum disorder, or pervasive developmental disorder 2. Alcohol or substance dependence or suicidality within the past 6 months 3. Current depression or anxiety in the severe range or higher 4. Sleep disorder present besides delayed sleep-wake phase disorder (Clinical Sleep History Interview) 5. Sleep solely in the prone position (i.e., on stomach) 6. Full scale IQ ≤ 80 (Wechsler Abbreviated Scale for Intelligence-II) 7. Use of any over-the-counter (e.g., melatonin, Benadryl) or prescribed sleep medication in the past month or planned use during the study 8. Changes to any psychiatric medication within one month of study enrollment or planned changes during the study 9. Use of photosensitizing medication within one month of study enrollment or planned during the study 10. Participation in behavior therapy for sleep and/or ADHD within 3 months of study enrollment or planned participation during the course of the study 11. Use of light therapy within 6 months of study enrollment or planned use during the study 12. Travel across \> 2 time zones within one month of study enrollment or planned travel outside of the time zone of participation during the study 13. Structural barriers to sleep (e.g., night shift work, extracurriculars scheduled until late in the evening, early rising for sports practice) 14. Medical or neurological condition (e.g., seizure disorder, chronic migraines) that would interfere in the individual's ability to participate