Adolescence represents a sensitive and vulnerable period for the development of internalising and externalising symptoms [1] and of a wide range of problematic behaviours, often persisting into adulthood [2]. Although problematic behaviours may occur within the framework of a normal development in adolescence, their recurrence could represent a risk factor for developing mental health problems at an older age [3]. Emotion Dysregulation (ED) is a multifaceted construct involving different components: a lack of awareness, understanding, and acceptance of emotions; an inability to control behaviours during an emotional distress; lack of access to adaptive strategies for modulating the duration and/or intensity of aversive emotional experiences; and an unwillingness to experience emotional distress [4]. A growing body of research indicates that heightened ED may increase the likelihood of engaging in maladaptive behaviours including Non-Suicidal Self-Injury (NSSI), unsafe sex, aggressive behaviours, substance use, and disordered eating [5, 6]. NSSI in adolescence is a serious health concern since it is a risk behavioural marker for the incidence of mental illness in general [7] and repetitive NSSI represents a predictive factor for progression to suicidal ideation or suicide attempts [8]. NSSI is relatively common in clinical settings [9, 10] with a lifetime prevalence rate of adolescent displaying self-harm behaviours that ranges from 13 to 23%. Furthermore, in non-clinical populations, approximately 4% of individuals reported a history of self-injury [11]. A recent retrospective study among adolescents who underwent child psychiatric consultation at an Italian paediatric emergency department found that about half of those hospitalized for suicidal behaviour or suicidal ideation reported a current or lifelong history of NSSI [8, 12]. Some studies underlined the key role of adverse childhood experience in the cascade of factors that leads to maladaptive behaviours. In the complex relationship between childhood maltreatment and maladaptive behaviours, ED seems to be determining. Findings from Arens and colleagues [13] among college students showed that a history of trauma experience leads to ED, which leads to impulsivity under extreme affect (urgency) as a means of coping, and this in turn, increase the likelihood of engaging in health-risk behaviours in an attempt to quickly reduce intense negative affects. Another recent study conducted among individuals who experienced childhood adversity showed that only ED and not impulsivity mediated the relation between childhood adversities and maladaptive behaviours, alcohol-related consequences, and risky sexual behaviours [14].

According to the biosocial model, temperamental vulnerability to ED becomes a core feature of externalizing problems and internalizing problems and places adolescents and young individuals at risk for more serious forms of psychopathology [3]. Personality traits were found associated also to problematic behaviours [15]. In particular, recent studies have demonstrated that individuals engaging in NSSI show higher scores on the personality dimension of Neuroticism, and lower scores on Agreeableness and Conscientiousness dimensions than those without NSSI [16–20]. NSSI, ED, impulsive behaviours and the presence of childhood traumatic experiences are key features of Borderline Personality Disorder (BPD) and might be considered potential risk factors for the development of the disorder and might be a possible target of preventative interventions. Indeed, individuals who engage in NSSI were found to be more likely to have a cluster B personality disorder [21]. Among the specific diagnoses comprising cluster B, investigations show that BPD is associated with heightened risk for a variety of self-damaging behaviours [22]. Furthermore, recent literature indicates that ED is an important transdiagnostic process [23], affecting BPD and eating disorders more than other conditions [24]. A recent longitudinal study [25] found that adolescents engaging particularly in self-injurious behaviours and risky alcohol use represent a specific high-risk group for the development of BPD.

The present study aimed to clarify the association among maladaptive behaviours, clinical dimensions and personality traits. Firstly, we sought to describe the presence of maladaptive behaviours (i.e. NSSI, binge eating, binge drinking, cannabis use, and risky sexual behaviours) in a sample of Italian community-dwelling students and to define different groups of adolescents, based on their engaging in types of maladaptive behaviours. Considering that it is well-established that NSSI and eating disordered behaviours frequently co-occur [26] we expected that in our sample NSSI and binge eating were distinguished by other types of maladaptive behaviours. Secondly, we aimed to evaluate the associations between adolescent groups engaging in different clusters of maladaptive behaviours and ED, depression, anxiety, impulsivity, trauma experiences and BPD related personality traits. In detail, we focused on exploring the putative impact of the clinical features on the relationship between BPD-related traits and the different clusters of maladaptive behaviours. We hypothesized that individuals with higher BPD related traits were more associated to NSSI and binge eating than other types of behaviours, and that these associations may be mediated by clinical features.