Common pathways of depression and pain.

Depressive disorders are chronic conditions that produce both emotional and physical symptoms. Increasing evidence suggests that in some patients with depressive disorders a neurodegenerative process may occur, highlighting the importance of early and aggressive intervention. Serotonin (5-HT) and norepinephrine (NE) neurotransmitter systems influence neuroplasticity in the brain, and both are involved in mediating the therapeutic effects of most currently available antidepressants. Some dual-action antidepressants have been shown to be effective in managing the pain symptoms associated with depression. These agents may have advantages over others by treating a wider array of physical symptoms. Additionally, these agents may also have a role in modulating neurogenesis and other neuroplastic changes, thereby leading to more complete recovery in patients suffering from the emotional and physical symptoms of chronic depression.