A number of studies have attempted to identify characteristics of children with ODD who do and do not go on to develop CD. Levels of sub-threshold CD symptoms have been identified as one such predictor (Rowe et al., 2002), with persistent physical fighting being perhaps of particular importance (Loeber et al., 1998). Rowe et al. (2002), however, found that effects of sub-threshold CD symptoms were not independent of family and environmental predictors. Of these, markers of family instability (including frequent house moves and step-family status) appeared most crucial in identifying cases of ODD that progressed to CD. In clinical samples, comparisons of ‘pure’ ODD and comorbid CD/ODD cases have largely found similar levels of environmental risk in both groups (Loeber et al., 2009). There is some evidence that parental hostility (Kolko, Dorn, Bukstein, & Burke, 2008) and lower socio-economic status (Greene et al., 2002) may be higher in comorbid CD/ODD cases.
