We recruited 738 unrelated controls [mean age 31.3±9.8 years and 68% males (n = 501)] from the Fundação Pró-Sangue, Hospital das Clínicas, Universidade de São Paulo (Blood Donation Center at the University of São Paulo School of Medicine). Exclusion criteria were: those with a history of drug abuse or recent use of illicit drugs, as were those with a history of psychiatric inpatient treatment or with a current psychiatric condition.
