"For males, marijuana (14.4%) was the substance most frequently used in their lifetime, followed by cocaine (8.3%). The drug of choice for females was also marijuana (2.0% lifetime use), closely followed by tranquilizers (1.8%). The rate of lifetime use of tranquilizers among females was slightly higher than among males."
Source
Medina-Mora María Elena, Borges Guilherme, Fleiz Clara, Benjet Corina, Rojas Estela, Zambrano Joaquín et al . Prevalence and correlates of drug use disorders in Mexico. Rev Panam Salud Publica [serial on the Internet]. 2006 Apr [cited 2012 Dec 07]; 19(4): 265-276. P. 270.
http://www.scielosp.org/sciel…
http://dx.doi.org/10.1590/S10…
