http://goo.gl/gyq7MA
There are, undoubtedly, many subtypes of the illness depression and the current clinical definition includes a list of mental and physical symptoms, some of which are severe—sleep disorder, lack of interest in usual activities, excessive guilt and rumination, lack of energy and fatigue, lack of concentration, change in appetite with weight loss or gain, a change in the level of movement either with agitation and retardation and suicidal ideation. Other important symptoms include pain and generally feeling lousy for long periods.
With such a long list of possible symptoms, there are many subtypes which include some of these symptoms, but not all. With eight discrete symptoms in the definition, there are hundreds of possible variants, but less in clinical experience. It is striking that many of these symptoms occur, also, with medical illness and infections—the “sick feeling” described in previous posts triggered by T cells. Also, a self-limiting form occurs naturally with grief.
Recent research shows that one particular subtype of depression—perhaps as much as a third to a half of cases—is closely related to the occurrence of inflammation, and it is possible that this group might respond to different kinds of treatment than the others.
Those people who have significant amounts of inflammation have the strongest responses to treatments that fight inflammation such as omega-3, celecoxib, and exercise, as well as medications that counteract the effects of cytokines. Those patients that have both inflammation and depression appear to need treatment for both. - See more at: http://jonlieffmd.com/blog/reciprocal-relationship-of-depression-and-inflammation#sthash.csCMdriQ.dpuf