The term chronic pain' can be defined as pain that lasts for more than three months. The difference between chronic and acute pain is that it is much more complex to find the underlying cause of chronic pain. Diagnosis might not reveal any outward injury and yet the patient could be undergoing debilitating pain and depression if the issue is not addressed immediately.
Chronic pain could well be termed as a disease and the pain could be classified as neuropathic pain as well as inflammatory pain. When the neurons are damaged (peripheral as well as central nervous system), then it could be termed as neuropathic pain. The pain could also be due to some inflammation and this in itself could cause some more damage to the neurons which may result in neuropathic pain.
Chronic pain is considered to be the major cause for depression in patients. A lot of attention has been placed on why the depression sets in (in patients with chronic pain) but there is not much information through the empirical studies that have been conducted to predict anything on the chronic pain models.
Recently, tests were conducted on chronic pain models and the findings have shown that although chronic pain is associated with depression, the main underlying psychological cause had not been determined. Studies on chronic pain models have shown that the chronic pain is a major contributing factor in an individual's perception of themselves. Patients who suffer with chronic pain perceive that they cannot have absolute control or mastery over various activities.
The test results of chronic pain models have confirmed that the other hidden variables are the underlying psychological factors which could be the main contributing factors of depression and not the chronic pain alone. Results from these studies are contrasted with other studies as well, where chronic pain and depression supposedly have the same etiology.