These findings are compatible with pre-clinical studies using a transgenic rat model of HIV, where Nemeth et al. 63 found that animals who exhibited depression-like behaviour had increased concentration of MCP-1 in the hippocampus, but treatment with meloxicam did not rescue depression-like behaviour in these animals, despite successfully inhibiting Mcp-1 gene expression. This evidence concerns the gene CCL2 and major depressive disorder.