Serum endocannabinoid levels in suicide attempters: A pilot study.

The search for a biomarker for suicide risk is a longstanding pursuit in clinical psychiatry. Literature addressing the role of endocannabinoids in suicide attempters (SA) is sparse. This cross-sectional study is aimed at comparing 8 AM serum concentrations of 4 endogenous cannabinoids (anandamide, AEA; 2-arachidonoylglycerol, 2-AG; N-palmitoiletanolamida, PEA; and oleoylethanolamide, OEA) in 30 suicide attempters (SA) and 12 psychiatric controls (PC). 8 AM AEA and PEA serum levels were higher in SA compared to PC without controlling for cannabis use (n = 42) (3.58 ± 5.77 vs. 1.62 ± 2.49, F = 3.04, P = 0.089; and 3.31 ± 4.82 vs. 1.21 ± 1.20, F = 6.22, p = 0.017, respectively). Serum ACTH was higher in PC compared to SA (32.11 ± 21.60 vs. 20.05 ± 9.96, F = 9.031, p = 0.0.005). After controlling for cannabis use in the urine test (n = 28), 8 AM AEA and PEA serum levels remained higher in SA compared to PC (4.57 ± 6.38 vs. 0.64 ± 1.11, F = 4.852, P = 0.037; and 4.35 ± 5.46 vs. 1.21 ± 1.25, F = 4.125, p = 0.053, respectively). The present study offers preliminary evidence about the role of AEA and PEA in suicidal behavior (SB). Furthermore, in the context of the mental pain model of SB, our findings suggest that some endocannabinoids may play a role in the pathophysiology of SB. Our pilot study deserves replication by other studies with bigger sample sizes.