Demographic and clinical characteristics of young adults by PER2 rs56013859 genotype: means and SE (in parenthesis) adjusted for sex.

1“Enriched” family adversity index as proposed by Rutter and Quinton (1977) measuring the presence of 11 adverse family factors covering characteristics of the parents, the partnership, and the family environment during a period of one year prior to birth;2obstetric adversity score counting the presence of 9 adverse conditions during pregnancy, delivery, and postnatal period such as preterm labor, asphyxia or seizures;3referring to the last 45 days;4number of standard drinks, each containing 10–13 g alcohol.