Plasma circulating micro-RNAs associated with alexithymia reflect a high overlap on neuropsychiatric outcomes

Alexithymia ("no word for feelings") is a personality feature that is common in patients with psychiatric disorders. However, little is known about biological causes and mechanism behind. Research so far focusses on genetic risk variants primary associated with depression, but analyses on epigenetic mechanisms are still missing.In a sample of n = 813 subjects from the "Study of Health in Pomerania" we analyzed the association between alexithymia and plasma circulating micro RNAs (miRNA). Significant miRNAs were compared to associations regarding depression and pathway analyses were performed.Two miRNAs were significantly associated with at least one of the alexithymia scores (hsa-miR-324-3p, hsa-miR-33a-5p) and three miRNAs additionally revealed a strong association pattern to alexithymia (hsa-miR-106b-5p, hsa-miR-484, hsa-miR-25-3p). None of these miRNAs was significantly associated with depressive symptoms in our sample. Literature research showed that all of the miRNAs have been found in association with several neuropsychiatric phenotypes.Main limitations are the lack of a replication sample as well as the limited number of miRNAs analyzed.This is the first analysis investigating the association between miRNAs and alexithymia. Results indicate that miRNAs are not specific for one psychiatric disorder but may influence biological mechanisms that are involved in various psychiatric conditions which might be relevant for future treatment options and improve the biological understanding of psychiatric conditions.