professionally speaking, if you feel your friend is about to harm himself, call 9-1-1...don't lie, tell them that your friend is having suicidal thoughts or may be thinking of harming himself. If he is then there may be grounds to apprehend him under the Mental Health Act....no not under arrest, apprehened....and he will be taken to the nearest hospital to speak with a doctor. If the emergency physician believes that he is going to harm himself etc, then he will issue whats called a Form 1 which is a doctors order for a 72 hour mental health evaluation...remember calling 9-1-1 may make you feel bad, but you're looking out for your friend..