Abuse not only leads to health risk behaviours, but also causes persistent increases in inflammatory markers like interleukin-6 (IL-6) [55], tumor necrosis factor-α (TNF-α) [56], and C-reactive protein (CRP) [57], which may add to the risk of inflammation-related diseases like diabetes and alter the pathogenic mechanisms of gene expression [58,59]. This evidence concerns the gene TNF and diabetes mellitus.