A good book on PTSD with a simple note without a lot of details (to minimize triggering) has worked best for me on referrals.
"I love you. I cannot stand to see you suffering so when there is help available. The [name of facility] at [address] has treatment for the severe trauma that has caused you so much suffering. Their number is [number]. If you'd like a ride, please let me know (if you are comfortable with that.)"
For one who was so depressed she had confided to me that she was having trouble not driving her kids and self into a tree, I decided the safety of her children was more important than our friendship. I went to her house, asked to use her cell phone, told her I was calling the local behavioral health counseling agency to make an appointment for her. When she said she wouldn't go, then I told her that the other option was for me to call 9-1-1 and report what she said to me.
She agreed on the first option, and I did. When the receptionist picked up, I said "Hello, this is [me - they know me well], and my friend [name] wants to make an appointment to be evaluated. I'm going to hand her the phone right now."
I handed her the phone, she made an appointment. Then, when I got home, I called the counselor she was going to see, and relayed the info I had, and explained why I really pushed her for an appointment. Counselors can never say anything about a patient. But they can always listen to someone else, though then can never act on the information given, it may help them understand how that person's behavior affected someone in their life (or at least, what my perception was.)
It's always ok to call a loved one's doctor, counselor, therapist to share what we seem to be observing. Unfortunately, good-hearted people don't, and abusers do. But professionals are able to discern intent over time when what they observe matches info given.
She began getting help, but she has never forgiven me. But while I regret that we couldn't salvage a friendship, she and her hubby remain good friends with my hubby.
I know without a doubt that I did the right, painful thing. I checked the next day, and she did go. She kept going. She seems to be doing well now, 2 years later. She did spread a lot of nasty rumors about me, but so what?
My hubby and I know the truth.
I've picked up too many bodies as a paramedic to believe in subtlety when human suffering is involved. Lives are more important to me.
I don't argue why they need to go. That's something I learned being a paramedic. The issue is, they're going to go. They know why, I don't need to tell them.
If I think they need to go, they can either go the easy way, or the not so easy way. I'm proud to say that as a paramedic, I never had to have the police take someone in handcuffs for being mentally ill. Compassion goes a long way. I was always careful to let them know it was concern that was behind my resolve, and that I would stay with them until I was sure they were in GOOD hands.
If all else fails, as a civilian, I have called the police, or the school counselor, or principal to ask for a well-being check. I have given them all my own details, what I've heard, what I've observed, and my fears that they are at risk of harming themselves or others. They can assess then using their own best training and judgment, and a report has been made. They know there might be something to watch out for. So if there is another incident, at least it increases the chances of them acting to help that person.
There is no relationship more important to me than that person's life. I've been most surprised when doing this how many people in that person's circle turn out to be very relieved, and have noticed the same symptoms but taken no action. Though they are the ones who get to keep that friendship, I get to keep my self-respect.
Eventually, some do thank us. But it's not necessary. I hope someone cares enough about me and my kids that if I was hurting my family, they would intervene. Though, I might be furious. :)
Hang in there. Take good self-care. None of this is your fault. I commend you for caring and loving that person enough to try. You are a wonderful person and deserve a happy, healthy life.