human 134 African American 127 Humans 123 female 111 male 101 Female 92 Male 83 African Americans 81 adult 81 Adult 63 Article 48 controlled study 47 Middle Aged 45 major clinical study 45 middle aged 45 psychology 43 young adult 43 United States 41 Young Adult 39 Caucasian 38 adolescent 38 Adolescent 36 ethnology 34 Hispanic 32 aged 32 Ethnic studies 30 Aged 26 article 24 child 24 European Continental Ancestry Group 23