Looking for no cost/low cost mental health resources

Hello, i am fairly new to reddit but, i have noticed that my son has been showing signs of depression, with even saying some pretty bad stuff. It came to a big shock when the police came to the house because one of his friends called for a wellness check because he was about to do something bad to himself. So right now i have been trying to find a place where i can get some low cost mental health test, just to see what my son has, because he's also been nagging that he has ADHD or something ever since he was 12. I hope this was clear enough, as english isn't my first language and i am also new to reddit.