"With regard to the ages of initiation of use, and focusing on the younger age group (15-24 years) where the probality of initiation use is higher, cannabis presents the earliest values, with an average age of 17 years and modal age 16 years, followed by ecstasy and hallucinogenic mushrooms with modal ages of 17 years and amphetamines with modal age of 18 years. Cocaine, heroin and LSD present later average and modal ages of initiation of use. Between 2001 and 2012, in the age group 15-24, there is a slight delay of the ages of initiation of use for most substances."

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.