Formula at night?

Theresa
Today I had my 2 week PP visit and I'm border line depression, my doctor suggested to give my son,who is a week and 4 days formula at one night time feeding for a week so he sleeps longer and get into a routine. I plan to ask my son's doctor at his appointment on the 27th. But what are everyone's opinions, my son is exclusively breastfed with an occasional bottle (pumped milk) so daddy can feed too.