I think it's important to add that sometimes a partner must get away from a partner who does not handle their depression appropriately, as the irritability can lead to abuse. The other partner can think "oh how can I support and understand you," all the time which might enable them, if they are not willing to take accountability and talk about their problem, then that partner is in for a miserable life, and I don't want to normalise staying when it slowly kills the other partner.
I think it's important to add that sometimes a partner must get away from a partner who does not handle their depression appropriately, as the irritability can lead to abuse. The other partner can think "oh how can I support and understand you," all the time which might enable them, if they are not willing to take accountability and talk about their problem, then that partner is in for a miserable life, and I don't want to normalise staying when it slowly kills the other partner.