This is a prospective randomized study with twofold aim. The first aim is to evaluate the impact of a school-based intervention focused on emotional regulation skills according to Dialectical Behavior Therapy for Adolescents. To this purpose, a sample of students attending the third year of high school (10th grade; 16-19 years) will be recruited, and the interventions will be delivered to the class of students during school-time. The outcomes will be evaluated (post-intervention, 3 and 6-months follow-up) in term of frequency of dysfunctional behaviours, use of emotional regulation skills, and psychological wellbeing. The study is also aimed to identify clinical and biological markers associated to ED in adolescents. To this purpose, youth psychiatric outpatients (16-19 years) will be recruited and compared to the participants of the community sample. All the participants will be evaluated through a comprehensive assessment including both clinical variables and biological variables. Biological evaluations will be conducted to measure cortisol levels during the day (awakening, noon and evening) and the inflammatory profiles

Emotional dysregulation (ED) is a multidimensional construct including lack of awareness and clarity about experienced emotions, nonacceptance of emotional distress, impulsivity, inability to pursue goals when emotionally distressed, and lack of regulatory strategies (Gratz and Roemer, 2004).

The background of the present study is threefold:

1. Adolescence is a heightened risk period for the onset of a wide range of mental disorder. Targeting emotional dysregulation (ED) in adolescence could be particularly relevant, indeed, there is a strong association between ED and dysfunctional behaviours such as substance-related problems (Barahmand et al., 2016; Simons et al., 2017), suicidal ideation (Miller et al., 2017; Rajappa et al., 2012), and self-harm behaviors (Peh et al., 2017).
2. Emotion regulation is a modifiable skill, and school-based prevention programs could be effective for the development of socio-emotional skills, and the improvement of psychological well-being (Taylor et al., 2017).
3. Stressful experiences, especially those occurring early in life, enhance the vulnerability for a spectrum of psychiatric disorders, via targeting both the Hypothalamic-Pituitary-Adrenal (HPA) axis system and the immune/inflammatory system (Lopizzo et al., 2015; 2017). Moreover, there is evidence that individuals exposed to early traumatic experiences exhibit difficulties in regulating their emotional responses (Jennissen et al., 2016). For this reasons, longitudinal studies focused on the association between HPA axis activity and the later development of psychopathology are of great interest because they may be helpful to identify possible risk factors for mental illness. However, only few studies analyzed the neurobiological correlated of ED in adolescents (Goodyer et al., 2000; Halligan et al., 2007).

The main aim of the present study aims to evaluate the impact of an intervention based on Dialectical Behavior Therapy for Adolescents (DBT-A) (Rathus & Miller, 2015, Mazza, et al, 2016) that will be delivered to the class of students during school-time. A total of 426 students attending the third year of high school (10th grade; 16-19 years) will be recruited. In order to optimize the representativeness of the sample, different type of school (i.e. professional institute; technical institute; arts, scientific and classical high schools) will be invited to participate to the study. Moreover, the randomization will be carried out in each school in order to control potential confounding variables associated to a specific type of school. Outcome will be assessed post-intervention, 3 and 6-month follow-up.

The second aim of the present study is to identify clinical and biological markers associated to ED. To this purpose, a clinical sample of youth outpatients (16-19 years) with mental disorders will be recruited and will be compared to the students of the community sample. All the participants will be evaluated through a comprehensive assessment including both clinical variables and biological variables. Clinical assessment will cover different domains: sociodemographic data, emotional dysregulation, psychopathological symptoms, social functioning, childhood trauma, stressful life events during previous year. Biological evaluations will be conducted to measure cortisol levels during the day (awakening, noon and evening) and the inflammatory profiles. Data about biological parameters will permit to investigate whether alterations in biological features related to stress response and inflammation can underlie ED and the vulnerability for psychopathology. Moreover, the same set of biomarkers will be evaluated at the end of the intervention in order to evaluate whether clinical improvements can occur via le modulation of these pathways.

Inclusion Criteria:

• Students attending the third year of high school (10th academic grade)
• Signed consent form

Exclusion Criteria:

• Mental retardation
• Asperger syndrome
• Autism spectrum disorders