How is depression diagnosed in the setting of chronic pain?
Diagnosing depression in the setting of chronic pain is challenging due to the presence of symptom overlap. Because of this, it has been suggested that questionnaires such as the Beck Depression Inventory may have less utility in the setting of chronic pain. One method that has been proposed to improve ease and specificity of diagnosis is to separately analyze somatic and cognitive-emotional symptoms. However, the association between these separate categories and variables such as chronic pain intensity and disability has yet to be elucidated.
It is important to note that a depressed mood does not always equate to a diagnosis of major depression; however, it is also important to realize that the presence of chronic pain does not exclude one from a diagnosis of major depression. Often, patients with symptoms of depression will attribute all of those symptoms to their chronic pain. A good number of chronic pain patients will endorse anhedonia, the inability to enjoy activities or experience pleasure, even when they are not experiencing pain or an increase in pain during the activities. In the same vein, poor sleep and poor concentration are also often attributed to pain when they are not direct physiologic effects of pain, and therefore they should be considered symptoms of depression.
Regardless of the presence or absence of a specific psychiatric diagnosis, a differential diagnosis including bipolar disorder, dysthymic disorder, and substance-induced mood disorder should be considered. A psychiatric or psychology practitioner with a focus in pain should be involved in order to provide the most comprehensive chronic pain care.