Regarding my isolated friend

Hello everyone

Hope you are all well. I'd really like some advice please.

My friend and I used to be good friends. Talk on the phone to each other etc. Then it stopped because he became isolated and lost contact with all his friends. He suffers with Social Anxiety and Schizo-affective Disorder. His isolation has caused him a lot of depression and stress. He rarely goes out. Doesn't answer the door or phone to anyone. The only contact he has is with his parents on a three week gap.

We haven't spoken to each other for 18 months. I have sent him a letter once a month and send a text/phone call once every two weeks. I do this because I value his friendship and love him very much.

A year ago, he had a breakdown. When I rang his mobile phone, I got the message, You have dialed an incorrect number. Please check the number and redial. I got very concerned but two weeks later, I dialed the number again. The phone was working.

Six months ago, I went to his flat and became friends with his neighbour. I got very concerned and wanted to know how he was. The neighbour gave me some insight about my friend. Saying he doesn't have anyone come see him and he is extremely isolated. He took my details and informed me he would get in touch the moment he sees my friend. That same day, I was very lucky to knock on his front door and talk to him. My friend didn't answer the door but he was listening.

That evening, his mum rang me to let me know my friend was ok. He wouldn't speak to me on the phone because he was very shy. Laughing and blushing. My friend doesn't have much experience with women. So he blushes and gets shy when I make contact. She did say I could contact her again to find out how he is doing.

After that call, he didn't contact me. I knew with his fear/anxiety he wouldn't. This was six months ago. Since then, I have done the same - one letter a month.

Three months ago, I tried to phone his mobile phone and the same message that happened a year ago. You have dialed an incorrect number. Please try the number and redial. Left it a few months and tried his phone number again last night and it's still the same.

I am feeling worried and going out of my mind. I'm really worried about him. I don't know why his phone is saying the same thing? Especially three months on.

I am having thoughts like what if he has commited sucide? What if he is ill? His mother isn't supportive towards him. When he gets ill, no one is there. His dad comes but I only have his mum's number.

Can someone please advise me please?