Husband may have postnatal depression

Has anyone else’s husbands or partners experienced this? We had our sweet boy 4 weeks ago. He’s absolutely perfect and healthy. Breastfeeding is going great, all in all I haven’t experienced any depressive symptoms. Maybe a touch of anxiety but I think normal new mom anxieties. My husband on the other hand has lost 20 lbs, is irritable, avoids being home...even during his paternity leave week he ran errands and had projects going the whole time and told me he just can’t stand being home. He has told me twice how depressed he is. He said he doesn’t find joy in anything. This is very unlike him. He has a history of depression but I’ve never seen him like this. He told me he isn’t suicidal but he is just plain sad from the moment he wakes up until bedtime. I’m encouraging him to talk to someone. I am exhausted myself feeding a newborn every 2 hours and essentially being alone all the time. Anyone have any experience with this? And any advice beyond just listening to him and being there for him?