In brief: Brain scans indicate that depression can increase pain perception
Brain scans indicate that depression can increase pain perception
Patients with major depression sometimes literally feel as though they are in pain. A small brain imaging study published in November 2008 suggests why depression might amplify the perception of pain.
Researchers from the University of California San Diego and colleagues recruited 15 young adults with major depressive disorder who were not taking antidepressants or other medication, and 15 age-matched controls with the same education level but without depression. Participants with depression completed a questionnaire to assess their psychological experiences with pain (such as whether they felt helpless when experiencing pain or ruminated over painful experiences). All participants underwent functional magnetic resonance imaging (fMRI) while fitted with an arm device that was heated to painful levels (46 to 47 degrees Celsius, or 115 to 116 degrees Fahrenheit). Researchers provided visual cues to alert participants that the heat stimulus would begin momentarily.
Compared with controls, the participants with depression showed increased brain activity, especially in the amygdala (a part of the brain involved in emotions), while anticipating pain. While the painful stimulus was applied, the depressed participants continued to show greater brain activity in the amygdala, and lower activity in other parts of the brain responsible for adjusting sensitivity to pain.