PTGS2 and depressive disorder: Other preclinical studies have also shown similar effects on anxiety-like behavior and proinflammatory cytokine expression within the brain using COX-2 inhibitors (Gamble-George et al., 2016; Lee et al., 2016), and human studies suggest that anti-inflammatory treatments such as COX-2 inhibitors may be effective in reducing depression symptoms (Köhler et al., 2014).