Global Perspectives

Depression is the most common psychological disturbance associated with medical illness. Over the last decade, evidence suggesting that depressive disorders may be related to abnormalities in specific brain systems and networks has emerged. Pain sensation and inhibition are said to be related to the complex interplay of peripheral and central mechanisms. The connections between pain-related components of the brain and emotional-related aspects of the brain on a physiologic level suggest that the experience of pain have sensory and affective dimensions1. The International Association for the Study of Pain notes that ''although pain is undeniably a bodily perception, it is also an emotional experience because it is almost always unpleasant '' 1.

Depression- a link to painful conditions:

Depression has been linked to pain conditions2. Reciprocal psychological effects of pain and depressive symptoms have been postulated: pain precipitates worry and pessimism, and distress impairs the ability to cope with pain1.

Recent research has examined physiologic and psychological mechanisms that may underlie the association between negative affect and pain among individuals with arthritis. Given that pain associated with arthritis has been identified as a major stressor and that stress has been associated with both increased pain and increased negative affect, much research related to potential mechanisms of negative affect and pain has focused on the role of stress.1

Studies suggest that depressive symptoms are more prevalent among patients with Rheumatoid Arthritis (RA) than in the general population. Depressive symptomatology also often overlaps with anxiety among individuals with arthritis. RA patients with significant levels of depressive symptomatology had higher pain scores than RA patients who were not depressed, and currently depressed RA patients had higher pain scores than individuals with only a history of depression. Increased levels of depression and anxiety are strongly associated with increased pain levels in RA individuals.1

Emotions and symptoms like pain are integrated into common cognitive schemas, and because of this integration, emotional experiences can exacerbate pain and vice versa. Negative affect and arthritis-related pain also may be associated with behavioral variables. One particularly important variable seems to be activity avoidance. Activity avoidance has been shown to predict depression and disability in individuals with chronic pain, and may significantly affect pain levels3.

In a study conducted by Breslau et al2 to examine the relationship between migraine and major depression it was observed that, life time prevalence of major depression was approximately three times higher in persons with migraine and with severe headaches compared with controls. This study also observed a bi-directional relationship between migraine and depression: migraine signaled an increased risk for the first onset of major depression, and major depression signaled an increased risk for the first time occurrence of migraine2.

Depression and concomitant medical conditions:

The reported prevalence of major depressive episodes in physically ill patients varies from 5% to more than 40%. The high prevalence of depression in various medical conditions is reflected by the special psychiatric diagnosis of "depression" due to a general medical condition4. Depression associated with various medical conditions is not merely a reaction to the incapacitation,pain and losses that accompany the physical disease process, but may be directly caused by activation of the immune system.

Antidepressant medication has been used successfully in treating depressive symptoms associated with medical illness. Both tricyclic antidepressant medications and selective serotonin-reuptake inhibitors are of proven value in treating depression associated with a wide range of conditions. Antidepressants have been shown to have many immunomodulatory effects. In vitro, exposure to antidepressants is mainly immunosuppressive, particularly with respect to cytokine secretion from human immune cells. In depressed patients, antidepressants may also have immunomodulatory effects. These data indicate that antidepressants provide useful treatment and prophylaxis against the development of illness-associated mood disorders.3