"Concerning the substances involved:
"• As in previous years, most cases involved only one drug (94%):
"• Mainly cannabis (78%) – 76 in 2011, 71% in 2010, 76% in 2009, 68% in 2008 and 64% in 2007;
"• 8% of these processes involved only heroin (9% in 2011, 14% in 2010, 11% in 2009, 14% in 2008 and 17% in 2007). 8% involved only cocaine (7%, 7%, 8%, 6% and 8%, respectively in 2011, 2010, 2009, 2008, 2007);
"• Similar to previous years, the predominance of occurrences involving only cannabis was found in all CDTs,
"For the processes involving more than one drug (6% in 2012, 7% in 2011 and 2010, 6% in 2009, 10% in 2008 and 2007), once more the association heroin-cocaine was predominant. Like in the last eight years. The association cocaine-cannabis, and for the first time the association ecstasy-cannabis surpassed the association heroin-cannabis."

Source

General-Directorate for Intervention on Addictive Behaviours and Dependencies (SICAD), "2013 National Report (2012 data) to the EMCDDA by the Reitox National Focal Point: PORTUGAL: New Development, Trends and in-depth information on selected issues" (Lisbon, Portugal: 2013), p. 95.
http://www.emcdda.europa.eu/h…
http://www.emcdda.europa.eu/a…