“…ADHD is believed to have multiple etiologies, many of which are biologically based and include genetic factors (see Barkley, 1998, for a review of studies). However, the expression of problems associated with ADHD, for example oppositional behavior, appears to have a strong relationship with social or environmental factors as well (Anderson, Hinshaw, & Simmel, 1994;August, Realmuto, Joyce, & Hektner, 1999;Barkley, 1998;Campbell, Breaux, Ewing, & Szumowski, 1986;Johnston & Mash, 2001). In particular, it has been argued that the development of oppositional behavior in children with ADHD is related to family variables such as coercive parenting and parental psychopathology (Moffitt, 1990;Whalen & Henker, 1999; see also Carlson, Tamm, & Hogan, 1999, for a review of studies).…”