Antidepressants are the most common type of medication prescribed. They have a variety of applications, including depression, anxiety and chronic pain. New research using rat participants suggests that the way antidepressants work on the brain may actually be counterproductive for people with certain forms of anxiety and chronic pain. It all comes down to the amygdala.
The amygdala is a region of the brain that is involved in both emotional processing (like pleasure and fear) and memory. As such, the amygdala plays an important role in treatments like exposure therapy that aim to divorce an emotional response from a given stimulus. Exposure therapy may be used to treat phobias, certain forms of anxiety (like OCD, panic disorder or PTSD) and chronic pain patients who are experiencing kinesiophobia (the fear of movement).
But researchers found that long-term use of SSRIs (selective serotonin reuptake inhibitors), a highly common type of antidepressant, can cause the amygdala to function differently, leading to inhibited ability to learn to respond to stimuli differently once the initial response has been deemed inappropriate. This ability is called extinction learning. Extinction learning is at the crux of exposure therapy, and the fact that SSRIs inhibit it is highly important for patients seeking treatment for anxiety and chronic pain. See more on the study at www.biologicalpsychiatryjournal.com.