Up to 50 percent of people who experience depression also experience physical pain, according to a 2002 article in Psychology Today. Pain occurs because the neural pathways that regulate mood also regulate pain perception. Research has also suggested that depressed mood amplifies the experience of pain, according to the American Pain Foundation.
Two neurotransmitters---chemical messengers in the nervous system---appear to be centrally involved in both mood and pain regulation: norepinephrine and serotonin. Several antidepressants target these two neurotransmitters, which therefore may effectively treat both depression and chronic pain: tricyclic antidepressants, selective-serotonin reuptake inhibitors, duloxetine and venlafaxine.
Tricyclic Antidepressants
Tricyclic antidepressants, or TCAs, were developed in the 1970s for the treatment of depression. They target both norepinephrine and serotonin by forcing the chemicals, after they're release from a neuron, to remain available until taken up by other neurons, thereby increasing their activity in the nervous system. Scientists believe that low levels of these neurotransmitters contribute either directly or indirectly to depression and chronic pain. Amitriptyline, a drug with the trade name Elavil, is the most commonly prescribed antidepressant for chronic pain, according to the Harvard Health Letter.
TCAs rarely present with some serious side effects, most notably cardiac problems. As a result, some psychiatrists prefer to prescribe a different class of medications for depression and chronic pain: selective serotonin reuptake inhibitors, or SSRIs. SSRI side effects are generally mild; however, only TCAs exert a local analgesic or pain relief effect, according to the American Pain Foundation. Therefore, TCAs may treat chronic localized pain conditions, such as lower back pain, more effectively.
Scientists and clinicians have also prescribed TCAs to treat pain conditions such as nerve damage, tension headaches, migraines and fibromyalgia with some success, according to the Mayo Clinic.
SSRIs
Pharmaceutical companies began marketing selective serotonin reuptake inhibitors in the late 1980s with the introduction of fluoxetine, known as Prozac. This medication targets the neurotransmitter serotonin. Similar to TCAs, SSRIs force serotonin to remain available to neurons, increasing its activity in the nervous system. While SSRIs may effectively treat depression, which in turn may decrease pain sensations, research suggests that SSRIs may not have a significant, direct therapeutic impact on pain conditions, according to the Mayo Clinic.
Duloxetine
Duloxetine, marketed as Cymbalta, is a newer antidepressant approved not only for depression but also for nerve injury pain, according to the American Pain Foundation. Physicians also use duloxetine for the treatment of fibromyalgia, a condition characterized by diffuse, nonspecific pain. Duloxetine targets both serotonin and norepinephrine using a mechanism similar to that of TCAs and SSRIs. A 2007 study cited by Medical News Today Research has suggested that duloxetine can specifically decrease the pain experience of those with major depression.
Venlafaxine
Venlafaxine, the drug known as Effexor, has potential as another antidepressant medication useful for treating pain conditions. Some scientists believe it to treat depression and pain more effectively than TCAs and SSRIs, but research data have been inconclusive, according to the Harvard Health Letter.
References
- "Psychology Today"; When Depression Hurts; Hara Estroff Marano; July 01, 2002
- Harvard Health Publications: Depression and Pain
- American Pain Foundation: Antidepressants for Pain
- Mayo Clinic: Antidepressants---Another Weapon Against Chronic Pain
- "Medical News Today;" In New Study, Duloxetine Reduced Non-Specific Pain and Emotional Symptoms Associated with Depression; no author; Mar 20, 2007
