Changes in stimulant drug use over time in the MACS: evidence for resilience against stimulant drug use among men who have sex with men.

Stimulant drug use is associated with numerous health problems among men who have sex with men (MSM). This paper describes how stimulant drug use changes over a four and one-half year period from 2003 until 2008. Participants were 2,389 men (17,222 person-visits) from The Multicenter AIDS Cohort Study (MACS)-an ongoing, prospective study of HIV infection among MSM. Group-based trajectory analyses of data from these men over the study period yielded a four groups solution: consistent users (9.8%), men whose use increased (5.4%), men whose use declined (6.9%), and abstinent or rarely-using men (77.9%). There were significant differences between groups in terms of demographic, behavioral risk and HIV serostatus. Men who increased or decreased stimulant drug use over time reported congruent changes in sexual risk taking. The fact that sexual risk levels parallel stimulant drug use over time suggests that finding ways to lower rates of stimulant drug use among MSM could be a tool in HIV prevention.