People not asleep by 10 pm have a higher risk of cancer and neurodegenerative diseases due to lower melatonin peak.

Labor day weekend at the Cancer Control Society Society, Christine Horner, MD spoke on the importance to be asleep by 10 pm.

www.garmaonhealth.com/beyond-sleep-10-ways-melatonin-helps-you-age-better-watch

Melatonin production starts at 9 pm.

http://articles.mercola.com/sites/articles/archive/2013/10/10/melatonin.aspx

Lithium

Low dose lithium reduces melatonin sensitivity to light. [J]

https://www.reddit.com/r/Electromagnetics/comments/3vpk87/j_melatonin_lithium_low_doses_of_lithium/

For more information on low dose lithium, see:

https://www.reddit.com/r/Electromagnetics/comments/3ltj2p/emf_draws_potassium_lithium_and_calcium_out_of/

People who cannot be asleep by 10 pm may need to get tested for lithium and if deficient take low dose lithium.