The Effect of the A118G Single Nucleotide Polymorphism of the Mu-Opioid Receptor Gene (OPRM1) on Loneliness, Social Support, Rumination and Mood
Open Access
- Author:
- Pisciotta, Colleen Margaret
- Area of Honors:
- Biobehavioral Health
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- William Gerin, Thesis Supervisor
David John Vandenbergh, Thesis Honors Advisor - Keywords:
- Mu-opioid receptor gene (OPRM1)
loneliness
social support
rumination
mood - Abstract:
- The A118G single nucleotide polymorphism (SNP) for the mu-opioid receptor gene (OPRM1) influences how both physical and social pain are experienced in primates and in humans. The G118 allele has been associated with decreased production of the associated mRNA and protein, increased pain after surgery and higher doses of morphine post-surgery, relative to the A118 allele. It has also been associated with increased sensitivity to social rejection. Based on these data, we hypothesized that the G118 allele would be associated with higher levels of loneliness (UCLA Loneliness Scale), lower levels of social support (Interpersonal Support Evaluation List, ISEL), higher levels of rumination (brooding; Ruminative Response Scale, RRS), lower levels of positive affect and higher levels of negative affect (modified version of the Positive and Negative Affect Schedule, PANAS) as well as greater changes in mood, in comparison to the A118 allele. These measures were administered to 107 undergraduate students at a large Eastern university (mean (M)=19.06 years, SD=1.19). Participants were randomly assigned to a recall task condition (either neutral recall, loneliness recall or academic failure recall). As part of a larger study, the participants were monitored for the duration of the study. Mood was assessed at the end of the initial baseline period, at the end of the recall task, and at the end of the recovery period. Buccal swabs were then used to collect DNA samples to determine the participant’s genotype for the A118G SNP. Those with the G118 allele (referred to as the G118 Group) showed a trend of having a higher mean loneliness score, a lower mean social support score, a higher mean rumination score, a lower mean baseline positive affect score and a higher mean baseline negative affect score than those without the G118 allele (referred to as the A118 Group); however, due possibly to inadequate power, these relationships were found to not be significant (ps>.05). Significant findings include that the positive affect of the G118 Group decreased to a greater degree than did that of the A118 Group in response to the academic failure recall task (p<.05), and that the positive affect of the G118 Group increased to a greater degree than did that of the A118 Group in response to the neutral recall task (p<.05). The trends suggest a possible association between the A118G SNP and social pain. Studies with larger sample sizes are required to further evaluate the relationship between the G118 SNP for the OPRM1 and social pain.