Certainly a reasonable hypothesis in light of the growing body of evidence that inflammatory factors are implicated in MDD and other psychiatric disorders. Fur

Certainly a reasonable hypothesis in light of the growing body of evidence that inflammatory factors are implicated in MDD and other psychiatric disorders. Furthermore, clinical observation supports the idea. It's quite common during the course of a cold or similar infection that patients will complain of having increased depressive symptoms. However inflammation is a very generic phenomenon which implies a greatly diverse range of influences operating to bring about emergence of MDD. For example, depression frequently accompanies post-surgical recovery which evokes inflammatory responses even in the absence of infection. While an infectious form of MDD is plausible, it wouldn't be the only important source of depressive conditions. In this sense, MDD is like a "final common pathway", the idea that clinically visible syndromes comes about through numerous paths. The key concept is that the mechanisms leading to the final path segment can be dissimilar and even non-overlapping. It means there's truly no distinct, singular "cause" of the condition, or rather there are numerous disease processes that happen to present similarly.