The Suicidal Mind by Edwin Schneidman.
Well written book for the lay person or professional. Dr. Schneidman compassionately and insightfully explores 10 common psychological themes of suicide such as loneliness and isolation. He examines 3 cases of individuals who attempted suicide, but lived. He also proposes 24 psychotherapeutic tools for recovery for the suicidal person. You might find this book to be a useful tool in therapy.