My wife suffers like your partner and it took awhile for her to get back on track ,but all i can say is if he does g to a doc they can help,they have helped us ,the right meds can do wonders ,tell him you love him ,call him but in the same sense give him space ...its hard to do but its like shy said "If you set it free ......."
I hope all works out for you
God grant me the serenity
to accept the things I cannot change;
courage to change the things I can;
and wisdom to know the difference.