This occasional paper presents national demographic subgroup data for the 1975-2018 Monitoring the Future (MTF) national survey results on 8th, 10th, and 12th graders' use of drugs, alcohol, and tobacco. The study covers all major classes of illicit and licit psychoactive drugs for an array of population subgroups. The trends are presented in tabular and graphic forms and cover demographic subgroups based on: (1) Gender; (2) College plans; (3) Region of the country; (4) Population density; (5) Education level of the parents (a proxy for socioeconomic level); and (6) Racial/ethnic identification. Detailed descriptions of the demographic categories are provided in the section starting on page 385 of this paper. The graphs and tables in this occasional paper present trend data for 8th-, 10th-, and 12th-grade respondents separately. Data for 12th grade begins with 1975, the first year in which a nationally representative sample of high school seniors was surveyed. Data for 8th and 10th grades begin with 1991, when the study's nationally representative annual surveys were expanded to include those lower grade levels.