A breakdown of parental alcohol dependence diagnoses may be seen in Table 1. Comorbidity is common in samples of male and female alcoholics and can complicate the interpretation of the presumed effects of parental alcohol dependence or familial genetic susceptibility on offspring psychopathology. Therefore, at the inception of the two family studies exclusion criteria were in place to limit comorbidity (Table 2), remaining comorbidity was taken into account statistically.
