Leo Sher, M.D.

A research report, “Anhedonia as a clinical correlate of inflammation in adolescents across psychiatric conditions” has recently been published in the World Journal of Biological Psychiatry (1).

Researchers from the Icahn School of Medicine at Mount Sinai in New York examined the relationships between a panel of inflammatory cytokines and key psychiatric symptoms (i.e., depression, anhedonia, anxiety, fatigue and suicidality) in adolescents across psychiatric disorders. The sample consisted of 76 adolescents, ages 12-20 (56.6% female), including 54 adolescents with DSM-IV psychiatric symptoms and 22 healthy control adolescents. The authors measured 41 cytokines after in vitro lipopolysaccharide stimulation. Participants completed several scales including the Snaith-Hamilton Pleasure Scale (SHAPS), a self-report measure of anhedonia severity. The SHAPS is a measure of consummatory reward across four positive valence subcategories: hobbies, social interactions, sensory experiences and food.

Healthy control adolescents and adolescents with psychiatric symptoms did not differ on post-lipopolysaccharide median fluorescence intensity values for any of the examined inflammatory cytokines at the false discovery rate corrected threshold. Controlling for BMI, age, sex and depression severity, the SHAPS scores among adolescents with psychiatric symptoms were significantly positively correlated with values of the following 19 cytokines at the a false discovery rate adjustment corrected threshold: FGF-2, Flt3-L, fractalkine, G-CSF, GM-CSF, IL-1a, IL-2, IL-3, IL-4, IL-7, IL-9, IL-10, IL-12p40, IL-12p70, IL-15, IL-17a, MCP-3, TNF-b and VEGF.

The authors conclude that general inflammation may induce reward dysfunction, which plays a significant role across psychiatric conditions. The authors also suggest that this study highlights the significance of incorporating dimensional analyses to address the heterogeneous nature of psychiatric conditions.

References

1. Freed RD, Mehra LM, Laor D, Patel M, Alonso CM, Kim-Schulze S, Gabbay V. Anhedonia as a clinical correlate of inflammation in adolescents across psychiatric conditions. World J Biol Psychiatry. 2019 Nov;20(9):712-722. doi: 10.1080/15622975.2018.1482000. Epub 2018 Aug 16.