AIMS: Adolescent mental health problems require treatment and care that are adapted to their needs. To evaluate this issue, it was decided to implement a multidimensional instrument focused on a global approach to adolescent social and behavioural functioning, combined with the ICD-10 classification. METHODS: The combination of an assessment interview and a classification tool enabled the method to integrate the measurement of several domains of patient-based outcome rather than focus on the measurement of symptoms. A group of 68 adolescents from an inpatient unit were compared with 67 adolescents from the general population. RESULTS: Results suggest that adolescents from the care unit adopt significantly riskier behaviour compared with adolescents from the control group. As expected, the main problems identified refer to the psychological and familial areas. A cluster analysis was performed and provided three different profiles: a group with externalizing disorders and two groups with internalizing disorders. On the basis of a structured interview it was possible to obtain information in a systematic way about the adolescents' trajectory (delinquency, physical and sexual abuse, psychoactive substance use). CONCLUSION: It was shown that treatment and care should not focus exclusively on mental health symptoms, but also upon physical, psychological and social aspects of the adolescent. A global approach helps in the consideration of the multitude of factors which must be taken into account when working with people with serious mental health problems and may help to turn the care unit's activity more specifically towards the needs of these adolescents.