Jonny Benjamin, 26, had tried to jump from London's Waterloo Bridge in January 2008 because he was struggling to cope with schizoaffective disorder, but was stopped by a passer-by who helped to change his mind.
Mr Benjamin started his campaign exactly six years after the incident, so he could thank the stranger. He named the search Find Mike because he had forgotten the man's name in his distressed state.
Benjamin has finally reunited with his mysterious life-saver after launching the hashtag campaign #FindMike.