To increase sample sizes for gene finding for ASB, we initiated the Broad Antisocial Behaviour Consortium (BroadABC). BroadABC represents a collaborative research initiative to conduct genetic analyses on a larger scale to identify biological mechanisms underlying the course of ASB. In designing BroadABC’s gene-discovery strategies, we weighed the benefits and costs of outcome measure heterogeneity in relation to the total sample size. We chose to maximize sample size by pooling the heterogeneous measures of the individual cohorts, including different age ranges, and jointly analysing their data. Our rationale is supported by genetically informative longitudinal studies demonstrating evidence for genetic continuity (the continuity in antisocial behaviour during childhood and adolescence is largely explained by genetic factors)(van Beijsterveldt, Bartels, Hudziak, & Boomsma, 2003). Moreover, prior studies examining the etiological connections between the externalizing spectrum, have shown that additive genetic factors account for 81% of the variance in externalizing behaviour(Krueger et al., 2002). Lastly, previous meta-analytical GWAS studies have successfully applied this joint analysis approach, by identifying additional loci associated with depressive symptoms and neuroticism(Okbay, Baselmans, et al., 2016). BroadABC thus focuses on
