Extra amounts of circulating serotonin may keep pain signals from reaching the brain. Coping with pain is stressful, and stress, in turn, may increase pain perception. If the blisters have healed, but the pain persists, what options do you have? Consider an antidepressant. Some studies have shown that low doses of antidepressant medications help relieve shingles-related pain, even in patients who are not suffering from depression. Don't spread them. Although it won't bring relief to you,…