Recent research has found correlation between someone undergoing major depressive episodes with neuroinflammation based on microglial activity in certain regions of the brain. Building off of those findings, a team of researchers found inflammation in unmedicated depression patients, eliminating the possibility of antidepressants causing inflammation and showing this association for the first time in living patients. 

There is a lot of interesting research being conducted in mental health recently and these findings raise an interesting question - could depression, or specifically suicidal ideation, be thought of as an immunological or an autoimmune disease? These observations are important in light of the recent push for a personalized medicine approach to depression and may alter the way depression is treated. Though further research is needed, we may see a future where anti-inflammatory drugs, even NSAIDs, are used to treat depression. 

Another recent study at UCSD analyzed a database of reported adverse events and found that four drugs in particular were associated with statistically lower reports of depression - ketamine, botox, diclofenac, and minicycline. Much research has gone into exploring the use of ketamine as a depression treatment, including the development of esketamine which is currently undergoing clinical trials. However, the finding around diclofenac, which is a non-steroidal anti-inflammatory drug, and minicycline, which is an antibiotic, would seem to align with the hypothesis that reducing inflammation has antidepressant effects.