Clinical Significance Of Endocannabinoid MRNA Expression In The Blood Of Patients With Major Depression:a Preliminary Study

Backgroud:The endocannabinoid system is a unique neuromodulatory system. It consists of cannabinoid receptors(CB1and CB2), their endogenous lipid ligands including arachidonoyl ethanolamide(AEA), and2-arachidonoylglycerol(2-AG) and the enzymes for ligand synthesis and degradation. Several studies have suggested that the endocannabinoid system may be involved in the pathogenesis and symptoms of major depression and cognitive impairment.Methods:39patients with major depression and35healthy volunteers were included and assessed with the Wisconsin Card Sorting Test and the Stroop Color Word Test.Their blood was collected and analyzed to test the possible differences of mRNA expression of cannabinoid receptor1(CB1) and fatty Acid Amide Hydrolase (FAAH) between depressive subjects and healthy controls.Results:K We found significantly lower levels of CB1receptor mRNA in the blood of patients with major depression when compared to controls(Mann-Whitney U Test; P=0.049).No differences were found regarding the expression of FAAH mRNA(Mann-Whitney U Test; p=0.158).2%After controlling for gender,age, educational level,body mass index and daily tobacco use,mRNA levels of CB1receptor exhibited a significant correlation with patients’ weight factor score of the Hamilton Depression Rating Scale (HAMD) (r=0.484, p=0.004); mRNA levels of FAAH exhibited a significant correlation with patients’cognition factor score of HAMD (r=0.345, p=0.045).3n There was no significant correlation between mRNA levels of CB1receptor or FAAH and patients’attention or executive functions.Conclusion:Alteration in endocannabinoid system may be involved in the pathogenesis of major depression.