Occasional OTC nonsteroidal anti-inflammatory drugs (NSAID) use is prevalent in the United States (25% aspirin, 9% ibuprofen, and 2% naproxen). An estimated 36 million Americans use over-the-counter (OTC) analgesics daily, however, considering the widespread use of analgesic agents, the overall incidence of serious drug-drug interactions involving these agents has been relatively low. Neuroinflammatory mechanisms have been implicated in depression, and NSAIDs have been found effective in animal models of depression both in monotherapy and when used to augment antidepressant drugs. However, results with NSAIDs have been mixed in human observational studies, with both better and worse depression outcomes reported. In animal studies, mice injected with BCG showed an increase in the total immobility time during the forced swim test (FST) and the tail suspension test (TST) and an increase in cerebral PGE2 and NO levels. Ibuprofen decreased the total immobility time during FST and TST and decreased cerebral PGE2 and NO levels, which was comparable to fluoxetine's effect. This would suggest that ibuprofen might have an antidepressant effect through inhibition of PGE2 and NO production.