The opioid receptor mu 1 (OPRM1) rs1799971 and catechol-O-methyltransferase (COMT) rs4680 as genetic markers for placebo analgesia

Abstract

The placebo effect is considered the core example of mind-body interactions. However, individual differences produce large placebo response variability in both healthy volunteers and patients. The placebo response in pain, placebo analgesia, may be dependent on both the opioid system and the dopaminergic system. Previous studies suggest that genetic variability affects the function of these 2 systems. The aim of this study was therefore to address the interaction between the single nucleotide polymorphisms opioid receptor mu 1 (OPRM1) rs1799971 and catechol-O-methyltransferase (COMT) rs4680 on placebo analgesia. Two hundred ninety-six healthy volunteers participated in a repeated-measures experimental design where thermal heat pain stimuli were used as pain stimuli. Participants were randomized either to a placebo group receiving placebo cream together with information that the cream would reduce pain, or to a natural history group receiving the same pain stimuli as the placebo group without any application of cream or manipulation of expectation of pain levels. The results showed that the interaction between OPRM1 rs1799971 and COMT rs4680 was significantly associated with the placebo analgesic response. Participants with OPRM1 Asn/Asn combined with COMT Met/Met and Val/Met reported significant pain relief after placebo administration, whereas those with other combinations of the OPRM1 and COMT genotypes displayed no significant placebo effect. Neither OPRM1 nor COMT had any significant influence on affective changes after placebo administration. As shown in this study, genotyping with regard to OPRM1 and COMT may predict who will respond favorably to placebo analgesic treatment.

Pain Processing in Elite and High-Level Athletes Compared to Non-athletes

“…Linear mixed models (LMM) were used to analyze the repeated data for pain intensity and pain thresholds. LMM's were chosen because these analyses are suitable for analyzing data with unequal group sizes, handle missing data without losing power in the analyses compared with standard general linear models, and allows for combinations of both fixed and random effects (Aslaksen et al, 2018).…”

Neurological and psychological mechanisms of the specific and nonspecific effects of acupuncture on knee osteoarthritis: study protocol for a randomized, controlled, crossover trial

“…Neurophysiological study indicated that genetic variations in neurotransmitter pathways mediating placebo effects provided the possibility of identifying placebo responders through genetic screening [43]. Based on recent studies, catechol-o-methyltransferase (COMT) and opioid receptor (OPRM1) participated in mediating the regulation of psychological process and pain process [44][45][46][47]. These genes will be selected as candidate genes for objectively assessing and predicting the specific and nonspecific effects of acupuncture, estimating correlations among gene polymorphisms, psychological factors, and brain activity.…”

Neurological and psychological mechanisms of the specific and nonspecific effects of acupuncture on knee osteoarthritis: study protocol for a randomized, controlled, crossover trial

“…Neurophysiological study indicated that genetic variations in neurotransmitter pathways mediating placebo effects provided the possibility of identifying placebo responders through genetic screening [44]. Based on recent studies, catechol-o-methyltransferase (COMT) and opioid receptor (OPRM1) participated in mediating the regulation of psychological process and pain process [45][46][47][48]. These genes will be selected as candidate genes for objectively assessing and predicting the speci c and nonspeci c effects of acupuncture, estimating correlations among gene polymorphisms, psychological factors and brain activity.…”