Meta-Analysis of Infectious Agents and Depression.

Depression is a debilitating psychiatric disorder and a growing global
public health issue. However, the relationships between microbial
infections and depression remains uncertain. A computerized literature
search of Medline, ISI Web of Knowledge, PsycINFO, and the Cochrane
Library was conducted up to May 2013, and 6362 studies were initially
identified for screening. Case-control studies detected biomarker of
microorganism were included. Based on inclusion and exclusion criteria,
28 studies were finally included to compare the detection of 16
infectious agents in unipolar depressed patients and healthy controls
with a positive incident being defined as a positive biochemical marker
of microbial infection. A customized form was used for data extraction.
Pooled analysis revealed that the majority of the 16 infectious agents
were not significantly associated with depression. However, there were
statistically significant associations between depression and infection
with Borna disease virus, herpes simplex virus-1, varicella zoster
virus, Epstein-Barr virus, and Chlamydophila trachomatis.