PTGS1 and depressive symptom measurement: For example, researchers have found that some patients with depression have normal or even reduced pro-inflammatory markers in serum (Whooley et al., 2007; Almeida et al., 2009; Dowlati et al., 2010; Lehto et al., 2010), and some classical anti-inflammatory drugs such as cyclo-oxygenase-1 (COX-1) inhibitors and non-steroidal anti-inflammatory drugs (NSAIDs) have been found to have no antidepressant efficacy and even cause depressive symptoms (Browning, 1996; Choi et al., 2009).