"lithium blocks the activity of an enzyme that 
affects the brain’s master clock­the part in charge of our circadian rhythms "

...

" ... in depressed people, cortical structures 
involved in thinking are too connected to the 
limbic system that focuses on emotional 
processing. Electroconvulsive therapy decreased 
that hyperconnection, she says, restoring the brain to balanced functioning. "

http://www.psmag.com/health/researchers-crack-codes-for-lithium-electroshock-42273/

www.peoplewho.org