Fig 3.
Association between tumor necrosis factor (TNF)-α plasma levels and obsessive-compulsive disorder (OCD) stratified by inclusion of subjects with comorbid depression. Meta-analysis failed to demonstrate a significant association between TNF-α plasma levels and OCD (standardized mean difference [SMD], −0.14 [95% CI, −0.37–0.08]; z=−1.3; P=0.21). There was a large and statistically significant degree of heterogeneity between trials (χ2=35.0; df=5; P<0.001; I2=86%). In stratified subgroup analysis, there was a significant moderating effect of inclusion of subjects with comorbid depression on the association between TNF-α levels and OCD (χ2 test for subgroup differences=20.4; df=1; P<0.001).