Reference
Kaminski, J. A., Schlagenhauf, F., Rapp, M., Awasthi, S., Ruggeri, B., Deserno, L., Banaschewski, T., Bokde, A. L. W., Bromberg, U., Büchel, C., Quinlan, E. B., Desrivières, S., Flor, H., Frouin, V., Garavan, H., Gowland, P., Ittermann, B., Martinot, J.-L., Martinot, M.-L. P., Nees, F., Papadopoulos Orfanos, D., Paus, T., Poustka, L., Smolka, M. N., Fröhner, J. H., Walter, H., Whelan, R., Ripke, S., Schumann, G., Heinz, A., & the IMAGEN consortium. (2018). Epigenetic variance in dopamine D2 receptor: a marker of IQ malleability? Translational Psychiatry, 8(169). https://doi.org/10.1038/s41398-018-0222-7
Review
In this article, the authors investigate the association between general IQ (gIQ) and various factors, including polygenic scores for intelligence, epigenetic modification of DRD2 gene, gray matter density in the striatum, and functional striatal activation elicited by temporarily surprising reward-predicting cues. The study includes a sample of 1475 healthy adolescents from the IMaging and GENetics (IMAGEN) project.
The researchers emphasize the significance of understanding the malleability of gIQ and its neurobiological correlates. Their findings indicate the equal importance of genetic variance, epigenetic modification of the DRD2 receptor gene, and functional striatal activation, which influences dopamine neurotransmission. These factors contribute to the variance in cognitive test performance and could potentially explain the "missing heritability" between estimates from twin studies and variance explained by genetic markers.
This study offers valuable insight into the factors that influence gIQ and highlights the need for further research on peripheral epigenetic markers. Specifically, future studies should investigate individual and environmental factors that modify the epigenetic structure, as well as confirm these peripheral markers within the central nervous system in longitudinal settings.
