You might be interested in this book:
A little dated and a little unrealistic but geared toward people who are family of those with mental/emotional issues.
It’s great you are seeking more information. Have you looked into mental health support groups? I attend one that has a group for family and friends in the US and is free. You can talk about challenges, find similarities, and find out ways of relating better. The two groups I know of are DBSA and NAMI. You can also contact a mental health hospital for groups or talks about relating to someone with mental health issues. It’s different than therapy because they are peer led and attended by new and old members that can offer advice and support.
I have depression and know others with mental illness and it’s hard when people without it don’t understand the challenges and ability to relate variations. But there are always boundaries for yourself so you don’t take on the responsibility for someone else. And there’s never an excuse for abusive behavior. If someone is verbally or physically abusive, they is something they need to work with a therapist and doctor with. It’s hard to live with and set boundaries with someone abusive.
I’ve been severely depressed and it’s difficult to respond verbally and bd active enough to do things. There is more than sadness for depression. It’s filled with lack of energy, lack of motivation and brain fog. It’s not a personal act of not trying hard enough usually. It sounds like your s/o is getting help for themselves which is a very positive sign.
And consider books. I see this one on Amazon that may help. I put spaces in in case links aren’t allowed. https:// www.amazon .com/When-Someone-Love-Mental-Illness/dp/0874776953/ref=mp_s_a_1_10?crid=3U4CZSS3KZ9A0&keywords=family+and+friends+mental+health&qid=1640201700&sprefix=family+and+friends+mental+health%2Caps%2C161&sr=8-10
I think it’s great that you are looking for information. Many people in relationships can take it personally that the other person cancels on plans or are not active enough physically and verbally. But when depressed, you can definitely be very loving and caring. It’s easier to interact face to face. There’s this energy barrier on the phone sometimes and it’s hard to answer texts right away. But it doesn’t mean they don’t love you. But it’s also wise to take your needs into account. Is the relationship fulfilling to you. Are you treated with respect and kindness. Do they respect boundaries. Are they showing signs of working with their mental health.
And definitely take into account your own mental issues. Are you getting enough good vibes back or are you feeling used and as if your concerns aren’t important. Openly talking about this is very helpful. Better to clear up perceptions to see if they are something workable or not. Whether your s/o will talk about your relationship. Even while depressed, good communication is important.