Refine
Year of publication
Language
- English (12)
Is part of the Bibliography
- yes (12)
Keywords
- reward anticipation (3)
- ventral striatum (3)
- adolescents (2)
- depression (2)
- monetary incentive delay task (2)
- nonreward sensitivity (2)
- orbitofrontal cortex (2)
- reward sensitivity (2)
- stress (2)
- Dopamine (1)
- Epigenetic Biomarkers (1)
- GIRK2 (1)
- Intelligence (1)
- KCNJ6 (1)
- Polygenic Risk Score (1)
- Reward Anticipation (1)
- alcoholism (1)
- amygdala (1)
- childhood adversity (1)
- conduct disorder (1)
- epigenetics and behaviour (1)
- fMRI (1)
- gene x environment (1)
- genetics (1)
- genome-wide association (1)
- human behaviour (1)
- human brain (1)
- human intelligence (1)
- learning and memory (1)
- metaanalysis (1)
- prediction (1)
- psychopathology (1)
- striatum (1)
- volume (1)
Background: Clock genes govern circadian rhythms and shape the effect of alcohol use on the physiological system. Exposure to severe negative life events is related to both heavy drinking and disturbed circadian rhythmicity. The aim of this study was 1) to extend previous findings suggesting an association of a haplotype tagging single nucleotide polymorphism of PER2 gene with drinking patterns, and 2) to examine a possible role for an interaction of this gene with life stress in hazardous drinking.
Methods: Data were collected as part of an epidemiological cohort study on the outcome of early risk factors followed since birth. At age 19 years, 268 young adults (126 males, 142 females) were genotyped for PER2 rs56013859 and were administered a 45-day alcohol timeline follow-back interview and the Alcohol Use Disorders Identification Test (AUDIT). Life stress was assessed as the number of severe negative life events during the past four years reported in a questionnaire and validated by interview.
Results: Individuals with the minor G allele of rs56013859 were found to be less engaged in alcohol use, drinking at only 72% of the days compared to homozygotes for the major A allele. Moreover, among regular drinkers, a gene x environment interaction emerged (p = .020). While no effects of genotype appeared under conditions of low stress, carriers of the G allele exhibited less hazardous drinking than those homozygous for the A allele when exposed to high stress.
Conclusions: These findings may suggest a role of the circadian rhythm gene PER2 in both the drinking patterns of young adults and in moderating the impact of severe life stress on hazardous drinking in experienced alcohol users. However, in light of the likely burden of multiple tests, the nature of the measures used and the nominal evidence of interaction, replication is needed before drawing firm conclusions.
General intelligence has a substantial genetic background in children, adolescents, and adults, but environmental factors also strongly correlate with cognitive performance as evidenced by a strong (up to one SD) increase in average intelligence test results in the second half of the previous century. This change occurred in a period apparently too short to accommodate radical genetic changes. It is highly suggestive that environmental factors interact with genotype by possible modification of epigenetic factors that regulate gene expression and thus contribute to individual malleability. This modification might as well be reflected in recent observations of an association between dopamine-dependent encoding of reward prediction errors and cognitive capacity, which was modulated by adverse life events.