"Same" In Behaviors, Different In Kinds:the Classification Of Adolescent Non-Suicidal Self-Injurers

In the field of psychology, non-Suicidal Self-Injury (NSSI, or Self-injury, SI) is an intentional and repeated destruction of one’s own body tissues without suicidal intentions or purposes, this behavior achieves no acceptance by society, which is not fatal or have low lethality. The nature of NSSI should be a kind of maladaptive coping method, whose core problem is emotional dysregulation. NSSI was thought to be contributed by early traumatic experiences, emotional dysregulation, impulsivity and some biological factors. NSSI correlates with many psychopathological problems or dysphrenia, and the suicidal risk of autolesionists suggests to be much higher compared to normal people (66times). In the recently published DSM-V, NSSI has been classified to be an undefined diagnosed disorder. NSSI is frequently seen among adolescents and young adults compared to older adults, with incidence of more than40%in adolescents in China. So, adolescents’ injury should be paid more attention.In previous studies, we found:(1) different injurers showed different behavioral manifestation;(2) every single factor has finite explanation to NSSI;(3) the incidences in adolescents, young adults, and older adults was lowered successively, which suggests that some adolescent injurers would self-cured in later life. So, authors (the author and her director) of this study hypothesize that there are two types in adolescent injurers, each of them having different behavioral manifestations, psychological meanings and influencing factors. One of the two is nonpathological injury, and with maturation, the injurers will convert to more healthy coping skills instead of self-injury to cope with their problems in life.On this basis, the authors raised a two-type hypothesis of adolescent injurers:all adolescent injurers could be divided into two types, one is pathological injury, which can be considered a form of psychopathology. The other is developmental injury, which can be considered a normative age-dependent response to the maturity gap that accompanies adolescence, similar to normal crisis by Ericksen. The authors also hypothesized that response sensitivity to social cues stimulus is an important character distinguishing pathological from developmental injury, and pathological injurers are more sensitive to some social stimulus than developmental ones.The purpose of this paper is to test the two-type hypothesis of adolescent injurers by5studies. Study1and study2aims to examine if there are two heterogeneous categories in adolescents injurers by different statistical methods. Based on the results of study1and study2, study3to study5are to test some important distinguishing characters between the two types injurers.In study1, we carried out taxometric analysis to examine the construct of adolescent injury by using the self-report instrument Adolescent Self-Injurious Behavior Questionnair in a sample of1343 adolescents from a junior middle school, a junior high school, a reformatory school and a juvenile prison. The sample is mixed, that is, both injurers and no-injurers were included. Mean age is15.77(SD=5.40). Three taxometric procedures were used:MAMBAC, MAXEIG, and L-Mode. Results of MAMBAC and MAXEIG indicates that the structure of adolescents injury is a categorical but not a dimensional, there is a pathological taxon in the behavior. Result of L-Mode were excluded due to poor indicator validity.In study2, we used latent profile analysis (LPA) to test numbers of injurers’ types and their characters with the same sample as study1. Two LPA were carried out, one with17self-injury types as indicators, the other with6indicators including self injury, early experiences, parents’love, parents’ control, emotion reactivity and emotion regulation difficulty. The two LPA results can and only can calculate a two-type model. Characters of the two types are consistent with the hypothesis of pathological and developmental injurers. Analysis results of two LPA and MAMBAC, MAXEIG correlates from0.68to0.87, which means the four analysis have good consistence, and adolescent injurers have two heterogeneous types:pathological injurers and developmental injurers.The purpose of study3is to test the differences on self-report influencing factors and clinical symptoms among two types injurers and no-injurers. Sample is the same with study1. Results showed that pathological injurers got the highest scores on emotion reactivity, emotion regulation difficulty, early experiences, and the lowest scores on parents’love, and no-injurers scored on the opposite. Any two groups have statistically significant differences.In study4and study5, we carried out two laboratory experiments respectively, to test two important distinguishing characters of pathological injurers:emotion reactivity and response sensitivity to social cues. Subjects were invited randomly from study1, including24pathological injurers,28developmental injurers and28no-injurers. In study4, we induced experiment emotions by two positive and negative videos. Self-report emotion and heart rate variability (HRV) were recorded after videos as indicators of emotion reactivity. Results showed no differences on both self-report and HRV between the three groups.In study5, we used facial expression (positive, negative and neural) recognition paradigm to examine response sensitivity of pathological injurers. Subjects were asked to response to emotional (positive and negative) expressions, and no response to neutral expressions. Results indicated that the three groups performed no difference on react time, accuracy and response bias. Although the two results of study4and study5didn’t support the assumptions, they can’t falsificate the theorical hypothesises so far. Later discussion showed that the experimental method should be properly adjusted.Conclusions:adolescents’self-injury is a two-type structure, one is pathological injury, with a proportion of about10%of all injurious adolescents, and the other is developmental injury, with a proportion of more than80%. The two types can be simply divided by injury. In the future, study and treatments of adolescent injurers should distinguish the two types.