['To explore change in human immunodeficiency virus (HIV) risk among teens in outpatient treatment for substance use disorders (SUDs).', 'From December 2002 to August 2004, 50 adolescents (13-19 years) with major depressive disorder, conduct disorder, and one or more non-nicotine SUD completed the Teen Health Survey (THS) at the beginning and end of 16 weeks of outpatient cognitive behavioral SUD treatment, which included a one-session HIV intervention. Changes in THS scale scores and specific item responses targeted by the intervention were assessed with paired t tests and Wilcoxon signed rank tests.', 'Pre/post mean THS scores significantly improved for two subscales: Measures of HIV Information (14.8-17.6; p < .001) and Beliefs about Condom Use (17.6-18.5; p < .05). Analyses of specific items showed trends for improvement in intentions to carry condoms and in the number of teens who obtained condoms. Not all of the risks targeted by the intervention showed significant change, but no change was observed in any area that was not specifically targeted.'] Do a one-session human immunodeficiency virus risk-reduction intervention in adolescents with psychiatric and substance use disorders?