Adolescence is a time for great physical and psychological change and it's often at that period of life that first use of psychoactive substances occurs. Although addiction is rare in teenagers, psychoactive substances abuse can have serious long-term health consequences on them. This is therefore a priority for all healthcare providers to identify early use and abuse of drugs in the youth's population.

The addictive process underlies environmental, genetic and individual causes. That is why it is somehow possible to identify individuals at risk based on some common sociological, cultural and environmental risk factors.

Due to the acute consequences of psychoactive substances abuses, Emergency Departments are main checkpoints for the screening of young drug users. Indeed, one patient out of five admitted in an Emergency Department shows a positive blood alcohol concentration regardless of the reason for their admission. This rate is twice as high as in the overall population. Hence, Emergency Departments are at the front-line for screening, caring, referral and transfer of psychoactive substances users. That is why the Emergency Department is the best place for this study.

In 2004, the special consultations of young consumers were founded in order to deal with these special cases where dependence is not yet established or installed and care has to be adapted to the age. Offering help to this age range represents a real challenge since only 20% of the teenagers come to visit this special consultations on their own initiative. The rest of teenagers are either obliged by their parents or sentenced by a court. The investigators assume that the repetition of care offered to the teenagers by repeated emergency admissions could trigger their own desire to overcome their drug use disorders and visit the Addictionology Department.

Inclusion Criteria:

• All patients aged 16 to 25 admitted at the Medical and Psychiatric Emergency Department.
• For adults: those who will agree to participate in this study
• For Minors from the age of 16: those who will agree to participate and want to exercise their rights by themselves or for whom one parent or legal guardian agrees for their participation.

Exclusion Criteria:

• patient who doesn't understand French
• patient under legal protection measures or guardianship
• confused person (GSC < 15)

Young people aged 16-25 inclusive, admitted to the Medical and Psychiatric Emergency Department (Building N) of the Edouard Herriot Hospital.