I’ve just had a really disturbing online chat with an old family friend. He is aged about 40 and seems to be experiencing severe psychosis. He is in a different country and sounds terrified. I suggested he go to the police or the hospital but he says he won’t. I’ve emailed his mum but is there anything I can say to help? He thinks people are after him and wanted proof that his sister was alive because he thinks she’s been murdered.