Nói chuyện với người đó. Khuyến khích người đó tìm kiếm sự giúp đỡ chuyên khoa. Nói với người đó rằng bạn sẵn sàng tiếp tục hỗ trợ họ.

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
If you suspect someone is depressed, give them the chance to talk it out. While professional help is needed, just talking can also help. A person living with depression needs support from loved ones.  Bring up your concerns with the person. You can start with something like, "I've noticed you've been acting strange lately and I'm a little concerned." Tactfully address any of the symptoms that concern you. For example, "You seem very tired lately. I know this could be for any reason, but have you