The loss of your friend sounds very sad and I hope you have found peace with it, but I'm not so sure this case matches up with your final conclusion. You say this: "His best friends were a huge joy in his life and they tried to get him professional help near the end because they could see that things were getting worse." If the people closest to the sad friend tried to persuade him to seek help and he didn't, I'm not really sure what else they or anyone else could have done.

Most in-patients at a behavioral health facility don't want to be there. Therapy is painfully hard work, and pharmaceutical physchotropic drugs don't actually make people feel good, just different. Staying in a locked behavioral health facility sucks. It's very much like jail, except the food is usually better and you have to wear a gown. You are also locked up with and/or recieving treatment with mentally ill people, and that can be depressing in itself. So there are a lot of reasons why people fail to seek or allow themselves to be guided into mental health care beyond a "stigma".

Of course reaching out to your friends and family more often is always good under any situation, but if you start pressuring one of them to visit a head shrinker, they might not want to talk you anymore.