The environment, brain and behaviour: results from large scale neuroimaging cohorts

One of the principal biological systems affected by environmental influences is epigenetic methylation. Here we present our recent investigations in the ENIGMA, IMAGEN, UK-biobank and the Chinese CHIMGEN behavioural neuroimaging genetic cohorts. In a genome-wide methylation analysis of ENIGMA datasets we demonstrate association of differential methylation with structural brain changes (Jia et al. submitted). Our research in IMAGEN shows that differential methylation also affects functional brain activity during impulsive behaviour and reward processing, influencing externalising behaviour (Ruggeri et al. Am J Psych 2015, JCPP 2018), but also cognitive functions, such as IQ (Kaminski et al. Transl Psych 2018).
Investigating the effect of psychosocial stress on epigenetics, we identified differential methylation in the SPDEF gene that mediates substance use behaviour (Tay et al. Am J Psych 2019). Furthermore, psychosocial stress also affects structural developmental brain trajectories (Quinlan et al. Mol Psych 2018), as well as brain activity during reinforcement behaviour. These correlations can be mediated by methylation of several genes, including the cortical neuroimmune regulator TANK (Mueller et al. Cereb Cortex 2019) and the nociception-receptor gene OPRL1 (Ruggeri et al. JCPP 2018).
Finally, we show using remote sensing satellite data that individual life experiences, such as psychosocial stress, exert their effect in a wider framework of physical environmental characteristics. In particular, we show that urbanisation (population density) is correlated with brain structure and internalising and substance use behaviour in Chinese and European young people (Xu et al. in preparation), as well as in adults of UK biobank (Li et al in preparation).
Together our data point to the necessity of including environmental information in the diagnostic stratification models for precision psychiatry.