First, the frequency or severity of psychopathology in adoptive parents is likely to be lower than in biological parents who rear their own children. For example, in an adoption study conducted in Sweden, registration by the state for “alcoholism” was rare for adoptive parents compared with biological parents (Cloninger et al. 1985). In addition, adoptive parents typically are older than biological parents. Consequently, the range of high-risk environmental exposures of children reared in adoptive families is likely to be restricted.
