ENGLISH :
Becker and Murphy's (1988) theory of rational behavior suggests that economic factors play an influential role in the decision leading to drug consumption and possibly dependence. Psychological models, on the other hand, emphasize internal regulatory cues that motivate drug use and play a contributory role in dependence. Until now, the confluence of both economic and psychological models has not been tested empirically. The present study used latent-variable structural equation modeling (SEM) to examine the influence of both economic (social anomie, unit price, and time spent acquiring drugs) and psychological risk factors (motivation, depression, and sexual risk behaviors) on self-reported ecstasy use. Data were obtained from 612 recreational ecstasy users in the United States and Australia participating in a NIDA-funded epidemiological study examining trends in ecstasy use. The sample was mainly white (61%), male (58%), and young (mean age = 23 yrs [5.25]). All of the hypothesized latent constructs were statistically reliable and correlated in the expected direction. A saturated SEM indicated that monetary and opportunity cost, but not income, significantly predicted ecstasy use. Among the psychological measures, motivational cues were the strongest predictor of both use and dependence. Inclusion of gender, age, race, education, and site variables did not appreciably alter the final model parameters. The implications of incorporating the role of economic factors in shaping a more refined understanding of addiction are discussed. Suggestions for future research and study limitations are also noted. (Author' s abstract)