What could be some effects of extreme loneliness oi a 22 year old?

Depression: Fereling of isolation is one of the cardinal signs of depression. "nobody understands or cares..".

Depression, : I agree with my colleague. Research in psychology shows all kinds of negative physical and psychological affects of extreme isolation. So don't stay there! find a small, therapy group: http://www.Agpa.Org/ under "need a group therapist?" it will help that extreme loneliness to be with others in a safe place with a trained leader.