The New Beginnings Program was a randomized controlled trial of two prevention programs, a program for custodial mothers, mother program (MP), and a dual-component program, mother plus child program (MPCP), for custodial mothers and their children, conducted between March 1, 1992, and December 31, 1993. Prior evaluation indicated positive effects of the MP on externalizing and internalizing problems at posttest and maintenance of positive effects on externalizing problems at 6-month follow-up. The current study involved a 6-year follow-up of a randomized controlled trial of the two intervention programs and a control condition, which was conducted in a large metropolitan U.S. city from April 1998 through March 2000. A total of 218 families (91 percent of the original sample) with adolescents between 15 and 19 years old were reinterviewed. The main outcome measures were externalizing and internalizing problems, diagnosed mental disorders, drug and alcohol use, and number of sexual partners. The study found that 11 percent of adolescents in the MPCP had a 1-year prevalence of diagnosed mental disorder compared with 23.5 percent of adolescents in the control program. Adolescents in the MPCP program had fewer sexual partners compared with adolescents in the control program. Adolescents with higher initial mental health problems whose families were in the MPCP program had lower externalizing problems and fewer symptoms of mental disorder compared with those in the control program. Compared with controls, adolescents whose mother participated in the MP and who had higher initial mental health problems had lower levels of externalizing problems; fewer symptoms of mental disorder; and less alcohol, marijuana, and other drug use. 1 figure, 2 tables, and 42 references