In summary, this is the first longitudinal study to examine the role of environmental risk exposure and OXTR methylation in the development of CU for INT− vs INT+ youth. Our findings show that: (i) OXTR methylation (at birth) prospectively associated with CU only for INT− youth; (ii) for this group, OXTR methylation (at birth) also associated with reduced experience of direct victimization (by peers and adults), which, to our knowledge, provides the first example (in humans) of what we refer to as an ‘evocative epigenetic-environment association’; (iii) OXTR methylation had greater temporal stability for the INT− vs. INT+ youth; and (iv) environmental risk (prenatal and postnatal) associated with CU only for the INT+ youth. As a result, the present study supports the existence of distinct developmental pathways to CU. Findings also identify targets and windows of opportunity for prevention as well as highlighting the salience of the prenatal period, both for INT− and INT+. More generally, the present study illustrates an innovative way to integrate longitudinal environmental and epigenetic information in the study of psychiatric disorders.
