Portuguese young adults (15–34 years old) were more frequent engaged in substance abuse (1.2%) than the general population, according to the Portuguese substance use annual report (2014). Alcohol was the most frequent substance use on youth adults. Cannabis was the most frequent illicit substance used (23.9% of users were considered dependent), with higher prevalence than previously reported. LSD (0.4%) use was also higher among young adults than in previous studies. Cocaine (0.4%), heroine/opiates (0.4%), ecstasy (0.3%), and hallucinogenic mushrooms (1.1%) had their consumption lowered among young adults.

To characterize a population of young adult psychiatric outpatients, regarding substance use and associated risk.

Socio-demographic characterization of our young adult unit outpatient users between 1st January 2015–31st July 2016. Substance use was assessed with the Portuguese version of Alcohol, Smoking and Substance Involvement Screening Test (ASSIST).

A total of 255 outpatients were observed during the timeframe; 58 outpatients were assessed with ASSIST: 44 females (75.9%) and 14 males (24.1%), aged between 16–33 years old (average: 20.95; median: 19.50). For tobacco, 3.5% had high risk, 37.9% moderate risk and 58.6% low risk; 22.4% had moderate risk of alcohol, 13.8% moderate risk of cannabis, and 20.7% moderate risk of tranquilizers. For others substances (cocaine, stimulants, inhalants, hallucinogens, and opiates) the risk was low.

In our sample, alcohol and cannabis use had the highest risk, as reported in the National Annual Report; however, we observed a moderate risk for tranquilizers use. In future care planning, youth mental health should address tobacco and alcohol abstinence, and preventive measures regarding anxiolytics should be undertaken, such as banning sale without medical prescription.