Fig. 1.

The dramatic increase in research on the topic of cytokine-induced depression is illustrated by the significantly higher number of original and review articles, rapid communications, letters to the editor and case reports published in the last 9 years, as compared to earlier decades. PubMed was searched from 1980 to present with “cytokines and major depression” used as the search terms. It is noteworthy that from 2000 to present, of the 616 articles published, 29% were review articles, highlighting the importance of this topic yet the need for more original research.