In recent years, there has been growing interest in research on alexithymia, as documented by a series of major systematic reviews in the international literature. Although the literature is not always unanimous about the definition of “alexithymia,” research suggests that alexithymia is a multi-dimensional deficit in affect recognition and regulation (Timoney and Holder, 2013). For some authors, it refers to a personality construct normally distributed in the population (Parker et al., 2008) whilst others use the term to denote a limited ability to identify, describe and communicate one’s feelings, which in turn reflects difficulties in affective self-regulation (Taylor et al., 1997). Thus a reduced ability to connect emotions with words (or “absence of words for emotions” as attested by its etymology from the Greek alpha = absence, lexis = language, thymos = emotions) has been used to define the construct of alexithymia (Taylor et al., 1997; Taylor, 2010). In general, the following clinical features have been considered as dimensions of alexithymia: difficulty in identifying and describing emotions, difficulty in distinguishing between subjective emotional states and the somatic components of emotional activation, poverty of imaginative processes, and cognitive style oriented toward external reality.

In line with previous investigation of healthy adults (Paivio and McCulloch, 2004), difficulties in identifying and describing inner feelings have been conceptualized as core components of alexithymia which may be associated with problems in building and maintaining close relationships with others and using social support to protect themselves against the potentially pathological influences of stressful events (Kojima et al., 2003). The difficulty in “identifying and describing ones’ own inner feelings” may make people reluctant to participate in social activities (Kojima, 2012).

It has been suggested that alexithymia is broadly associated with various mental and physical health problems (Cerutti et al., 2016, 2017; Gatta et al., 2016). Individuals with alexithymia are more likely to have a limited ability to adaptively cope with stressful conditions and tend to encompass unhealthy behaviors such as alcohol and drug use (Lumley et al., 2007). Some studies have indicated that self-injuries are associated with a higher level of alexithymia than non-self-injuries among high school students and adolescent inpatient populations (Garisch and Wilson, 2010; Cerutti et al., 2014). Other studies have highlighted that adolescents inpatients with non-suicidal self-injury (NSSI) are more likely to have a pervasive and comprehensive Theory of Mind impairment (Laghi et al., 2016).

Non-suicidal self-injury is defined as the intentional injuring of one’s body without apparent suicidal intent and for reasons not socially acceptable within one’s culture (Muehlenkamp et al., 2012). Similar to other risky behaviors (e.g., alcohol and substance abuse), it typically begins between the age of 13 and 15 years (Favazza and Rosenthal, 1993; Hilt et al., 2008; Cerutti et al., 2011; Muehlenkamp et al., 2012). The transition to adolescence seems to mark a developmental period distinguished by its increased rates of NSSI behaviors (Peterson et al., 2008; Cerutti et al., 2014; Manca et al., 2014). International studies have revealed a wide variability in prevalence rates, with percentages ranging from 12 to 56% in non-clinical populations of adolescents (Cerutti et al., 2011; Muehlenkamp et al., 2012) and from 20 to 80% in clinical populations (Hilt et al., 2008; Ferrara et al., 2012; Cerutti et al., 2014; Kara et al., 2015).

During the last two decades, NSSI has attracted the attention of researchers among clinical and non-clinical settings (Klonsky and Muehlenkamp, 2007; Nixon et al., 2008; Nixon and Heath, 2009; Muehlenkamp et al., 2012; International Society for the Study of Self-Injury, 2015; Zetterqvist, 2017) since this phenomenon is widespread across the Western world. It represents a serious public health problem (Klonsky et al., 2013; Cerutti et al., 2014; Serafini et al., 2017) owing to the greater risk for later suicidal behavior especially among individuals who engaging NSSI repeatedly (Joiner, 2005; Joiner et al., 2012; Grandclerc et al., 2016).

There is evidence that NSSI is generally used to cope with distressing negative affective states, especially anger and depression, and mixed emotional states. However, to date, there is a paucity of studies exploring how individuals who engage in self-injury may experience difficulty expressing and verbalizing emotions in early adolescence and adolescence (Cerutti et al., 2014). Research is needed to examine a broader range of stressful childhood experiences, as few studies have examined the relationship between negative experiences or stressful life events, alexithymia and NSSI among young people. In a previous study, Paivio and McCulloch (2004) found that alexithymia partially mediated the relationship between traumatic experience and self-injurious behaviors among female undergraduate students.

Furthermore, it has been suggested that stressful and traumatic life events (e.g., abuse) in childhood may be related to self-injurious behavior in adulthood (Ross and McKay, 1979; Terr, 1991; van der Kolk et al., 1991). Studies have also highlighted that not all individuals with a history of abuse later engage in NSSI, and not all individuals who self-injure have been abused (Klonsky and Muehlenkamp, 2007). The stress exposure model of psychopathology indicate that experiencing higher rates of life stressors or negative life events contribute to a higher risk for negative mental health outcomes (Liu et al., 2014). Nock (2010) suggested that stressful life events have the similarly prominent role as proximal risk factors for NSSI behavior, since in presence of stressful life events specific physiological responses are experienced by some individuals, who further may be at risk for engaging in NSSI as a coping strategy. This is more evident in individuals with difficulties in emotional regulation (Tang et al., 2016). Additionally, negative life events ranging from traumatic stressors to major life changes are consistently associated with suicidal ideation (Liu et al., 2014). It is well known that environmental influences have a particular impact on children’s psychological development, especially the ‘emotional climate’ provided by the parents (Taylor, 2010). Studies have highlighted that early attachment difficulties may contribute to later self-injurious behaviors (van der Kolk et al., 1996; Conterio and Lader, 1998; Walsh, 2006). Specifically, Gratz et al. (2002) examined the role of the parent–child relationship as a risk factor for NSSI revealing that emotional neglect and the quality of the parent–child relationship were associated with risk of developing NSSI later. In view of new forms of sociality, adolescents make an important transition from family to peer group through gradual autonomy from primary attachment figures. The interest toward the peer group, with whom adolescents can share experiences and affection, becomes a determining factor to promote the growth and construction of personal identity.

Although research supports the relation between stressful life events and NSSI behaviors, to date there are few studies that have been undertaken on the degree to which stressful life events lead to NSSI among adolescents, except for research focusing on childhood abuse and other severe early life adversities (Tang et al., 2016). Only a small number of empirical studies have investigated the relationship between NSSI and core alexithymic features (i.e., difficulty in identifying and describing feelings) in different populations while no systematic review of the literature has been conducted to date. Moreover, the overall relationships among the difficulty in identifying and describing feelings, quality of parental and peer attachment, NSSI, suicidal ideation, and of stressful life events among young adolescents have not been sufficiently investigated.

The primary aim of this study was to investigate the difficulties in identifying and describing feelings, two core facets of alexithymia, and NSSI behavior among a sample of Italian students. Our findings highlighted that self-harmers have higher difficulties in identifying and describing their own feelings, confirming the fact that they are perplexed about their emotions and find it difficult to distinguish between them (Taylor et al., 1997; Hamza et al., 2015). This result moves us in the direction of supporting an affect regulation function of NSSI in which adolescents with difficulties in identifying and describing their feelings may use NSSI as a way of regulating their emotions (Klonsky and Muehlenkamp, 2007), and is consistent with a previous study using a community sample of high school students (Laukkanen et al., 2013).

Importantly, we also tested a theoretical mediational model in which the difficulty in identifying and describing feelings was the mediator of the associations between NSSI and quality of attachment toward both parents and peers. Results supported the hypothesized mediation model: low levels of quality of attachment may enhance the risk of both NSSI and suicidal ideation by compromising adolescents’ abilities to identify their own feelings. This result is in line with findings showing the importance of quality attachment in emotion regulation. Specifically, a negative environment (i.e., neglectful environments) influences the nature and quality of the relationships in which parents and children engage and it may interrupt the development of healthy emotion regulation skills in children and adolescents (Trickett et al., 2011; Peh et al., 2017; Williams et al., 2017). There is evidence that a lack of attachment security in early life affects the development of processes involved in emotion regulation (Schore, 2001; Taylor, 2010). In other words, the child who in absence of a secure attachment to parents fails to develop adequate self-regulatory capacities (Taylor, 2010). Similarly, our results also support the importance in extending the investigation on attachment beyond early childhood through to adolescence, and particularly in investigating the perceptions adolescents have of the quality of their actual attachment relationships. Specifically during adolescence age, the interactions with peers assume an increasingly higher priority, attachment behavior is also often oriented toward non-parental figures (Kerns et al., 2006) because peers are perceived as primary sources of consolation and support.

Accordingly, it seems that poor emotional bonds with both parents and peers may act as distal risk factors for developing later psychopathology. Our findings confirm that NSSI behaviors can be considered as a dysfunctional emotion-regulation strategy in presence of a inability to identifying feelings, consistent with recent results of Peh et al. (2017) that suggested how NSSI may be viewed as maladaptive attempts to cope with negative effects.

However, our model also suggests that these negative effects might be counteracted by helping adolescents understand and recognize their own feelings. In a systematic review of the literature exploring the link between alexithymic features and NSSI, Norman and Borrill (2015) showed that individuals, who are able to understand and communicate their feelings, are likely to engage in NSSI behaviors in order to regulate their emotions. Furthermore, identifying and labeling an emotional experience in itself reduces emotional intensity that, in turn, may help to prevent the perceived need to engage in NSSI (Sleuwaegen et al., 2017).

This result can have high clinical relevance if we consider that, to date, only a few studies have investigated the mediational role played by core alexithymic facets in association with NSSI behaviors and other risk factors during early adolescence and adolescence. For instance, Garisch and Wilson (2010) found that alexithymia mediated the association between bullying and self-harm in high school students. This is in line with the findings of the present study supporting the hypotheses that the inability to regulate and communicate emotions in a normally adaptive way plays an important role in NSSI behaviors. The role of alexithymia in maladaptive behavior was also explored by Swannell et al. (2012) who reported that alexithymia (i.e., difficulty in describing feelings) partially mediated the effect of childhood abuse on self-harm in females but not in males.

Consistent with other studies, our findings indicated that NSSI is moderately prevalent among a non-clinical adolescent population (Hilt et al., 2008). Specifically, 28.8% reported one or more lifetime histories of NSSI behaviors (<5) while 1.4% reported engaging in repetitive NSSI (five or more episodes during the last year) using different methods.

Moreover, adolescents who engaged in NSSI showed a poor perception of quality of attachment with both parents and peers. This is consistent with literature indicating that early attachment relationships have important implications for mental health later in life (Arbuthnott and Lewis, 2015) and in line with study Hallab and Covic’s (2010), which measured attachment by the same tool adopted in this paper and showed that those who self-injured had the worst perceived quality of attachment to parents compared with those who did not intentionally hurt themselves.

With regards to suicidal ideation, findings revealed that suicidal ideation is negatively related to quality of attachment to parents and peers and positively correlated with DIF. Suicidal thought is also positively correlated with the number of stressful events.

Parcel and part of our analysis, we also confirmed that a greater number of life events (as reported by adolescents) were an additional risk factor for NSSI episodes. While a positive perception of the quality of attachment to parents and to peers was related to a smaller number of NSSI behaviors.

However, while a history of childhood trauma has been reported as a common risk factor for NSSI, the role of family, peer relationships and attachment has not been thoroughly explored. Given the limited studies investigating these interrelations, the current study is an important contribution to the extant literature. With regard to the relationship between stressful life events and NSSI, a previous cited study by Paivio and McCulloch (2004) restricted its focus exclusivity on child maltreatment as predictor variable in their mediational model, and did not consider other types of traumatic or stressful life events.

Conversely, consistent with recent research findings (Cerutti et al., 2011; Liu et al., 2014), the present study extend the focus on other important adverse experiences not only maltreatment. In fact, our results provide evidence that an increased frequency of NSSI is associated with a greater number of stressful life events as experience of sexual harassment, being victim of bullying, witnessing potentially traumatic events, etc.

All of the authors have substantially and equally contributed to the development and preparation of the manuscript. Furthermore, all the authors have approved the final version of the manuscript. Finally, all authors have agreed to be accountable for all aspects of the manuscript in ensuring that questions related to the accuracy or integrity of any part of it are appropriately investigated and resolved.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.