What is the Hamilton depression rating scale?

Treatment effect score,17 items, score from 0-52, MDD if above 15, 7-15 we are getting a response >50% reduction, <7 remission 67% of pt respond to antidepressants, 33% remit w/any type of AD, after 1 year of treatment w/4 ADs 67% will remit, relapse is less for pt who achieve remission