Speaking from experience at the very lowest you can "shut down" lacking motivation to do anything. The thing is mood and motivation are shockingly separate and

Speaking from experience at the very lowest you can "shut down" lacking motivation to do anything. The thing is mood and motivation are shockingly separate and antidepressants are a "try and see what fits". So if it combos to improved motivation while still feeling suicidal that is a bad combination. As for the why biochemically it not certain but it involves longer cycles. Ketamine is one faster acting hope but it isn't widely used from other concerns.