It is estimated that up to 85% of chronic pain patients suffer from severe depression. Sometimes pain is a symptom of pre-existing depression, and sometimes the depression comes as a result of the effects of chronic pain. With potentially one fifth of the US population suffering from chronic pain, understanding the association between depression and pain, and the subsequent treatment of the two, is becoming more and more important.
The areas of the brain in charge of mood management include the prefrontal cortex, the amygdala, and the hippocampus. Evaluation of the brain post-injury shows that body pain is controlled by most of the same regions of the brain. The chemicals in the brain associated with depression, such as serotonin and norepinephrine, play a major role in pain perception. When the regulation of these chemicals fail, which can be the case with depression, pain perception is intensified. Additionally, autopsies performed on patients who had chronic depression showed a consistently smaller prefrontal cortex. This could potentially mean that depression can cause a physical change in the brain, therefore leading to a chronic, and possibly permanent change in the brain structure.
Another correlation between chronic depression and pain is due to the similar impacts both can have on someone’s quality of life. Depression can cause a lack of interest in hobbies, activities, socialization, and can therefore lead to isolation. Without the ability or desire to partake in everyday activities, more focus is paid to pain, which increases the perception of pain. Pain can cause immobility, loss of ability to work or function, also leading to isolation, and therefore depression. Therefore, regardless of which came first, the onset of chronic pain or depression can either cause or increase the severity of the other.
Being aware of the correlation between these two debilitating diagnoses can help lead to more effective treatment. Physical therapy can help increase a patient’s strength and mobility, which is widely known to help with pain, however movement itself produces endorphins, the chemicals which help with happiness and reward, and therefore can decrease depression symptoms as well. Psychotherapy is widely known to help with depression, however this can also help to alter a patient’s perception and focus on pain, and can either decrease the pain symptoms, or help a patient better cope with chronic pain symptoms. Many antidepressant medications are also used with chronic pain management, regardless of whether or not a patient has been diagnosed with depression as well.
Overall, chronic pain can be extremely debilitating on its own, but unfortunately it commonly occurs with depression. Treating one without acknowledging the other can lead to insufficient treatment of both, so understanding their correlation in onset, as well as treatment, can help patients improve their quality of life, both mentally and physically.
Depression and pain. (2009, June). Retrieved January 14, 2020, from https://www.health.harvard.edu/mind-and-mood/depression-and-pain.
Sansone, R. A., & Sansone, L. A. (2008, December). Pain, pain, go away: antidepressants and pain management. Retrieved January 14, 2020, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2729622/.
Sheng, J., Liu, S., Wang, Y., Cui, R., & Zhang, X. (2017). The Link between Depression and Chronic Pain: Neural Mechanisms in the Brain. Retrieved January 14, 2020, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5494581/.