By Noa Mecica

About one third of individuals who are clinically depressed do not respond well to any drugs currently on the market, with these drugs often leading to undesirable side effects. An emerging body of evidence is suggesting that the immune system along with inflammation play a role in the development of major depression disorder.  Specifically, several studies have demonstrated that depression is often associated with immune system dysregulation and high cytokine levels. These affect how we feel by influencing our metabolism, sleep, stress, and mood. The question then becomes, can anti-inflammatory drugs be used to alleviate some of the symptoms of depression, as seen with other inflammatory linked diseases such as cancer?

A recent study in the Journal of Neurology, Neurosurgery, and Psychiatry examined the efficacy of various anti-inflammatories in treating depression. Researchers scanned numerous databases and examined 30 randomized controlled trials with 1610 participants who reported changes in depression scales. The researchers sought to examine the efficacy and safety of anti-inflammatory treatments as either standalone or supplementary treatments in patients with major depression. Anti-inflammatory drugs were defined as NSAIDS, cytokine inhibitors, omega-3 fatty acids, statins, corticosteroids, minocycline, modafinil, pioglitazone, and N-acetylcysteine (NAC).  Of these 30 studies, 26 were analyzed and demonstrated that these anti-inflammatories were 52% more effective in reducing overall symptom severity, and 79% more effective at eliminating symptoms than placebo. Interestingly, deeper analysis of these studies revealed that NSAIDS, omega 3 fatty acids, statins and minocyclines were the most effective. Moreover, the best results were seen when given as a supplement to current antidepressant treatments. 

Does this mean that those suffering from depression should begin taking anti-inflammatories daily? Not quite. Although promising, this review contains many limitations. Non only did depression scales vary, but the time periods used to track depression scores were inconsistent across studies. Additionally, small sample sizes used in many of the studied trials do not constitute a representative sample, making it difficult to assert the effectiveness of such a treatment. Overall, while authors of this paper were careful in their analysis, their research was based on various trials that between them lacked the consistency necessary to be considered generalizable, raising red flags. Although no major safety concerns or side effects were associated with these anti-inflammatories, a thorough analysis of a bigger data set with proper controls is necessary before recommending this course of treatment for depression.  Nonetheless, these findings contribute to an expanding field, providing evidence to support the link between inflammation and mental health symptoms.

References:

Bai, S., Guo, W., Feng, Y., Deng, H., Li, G., Nie, H., … Tang, Z. (2019). Efficacy and safety of anti-inflammatory agents for the treatment of major depressive disorder: a systematic review and meta-analysis of randomised controlled trials. Journal of Neurology, Neurosurgery & Psychiatry. doi: 10.1136/jnnp-2019-320912