Silver Book Fact
In one study, around half of the patients with persistent pain reported that they had considered suicide.
Hitchcock L, Ferrell B, McCaffery M. The Experience of Chronic Nonmalignant Pain. J Pain Symptom Manage. 1994; 9(5): 312-8. http://www.jpsmjournal.com/article/0885-3924%2894%2990190-2/abstract