How can you help someone overcome a hoarding problem?

If it's bad housekeeping and a lifestyle choice, I'd suggest looking for better roommates.

If it really seems like an issue, then it's a disorder of the OCD family and requires intervention and therapy to resolve. Good luck.

They need therapy. It's a mental illness.

I personally cannot live with someone like that. I'd throw all things out and clean the place. I have difficulty living anywhere cluttered or disorganized.

Um it depends if it’s just messiness or a mental issue I guess. My friend’s mum has full on hoarding and it’s horrendous..I think therapy is needed

She's died and I've sent more than 2 vanloads to recycling.

Take one item of shit a day with you

Keep it one room or closet.