A meta-analysis of the prevalence of Different functions of non-suicidal self-injury.

Background A broad variety of different functions can underlie acts of Non-suicidal self-injury (NSSI). Whilst research so far has identified many of the commonly reported functions, no reliable estimates of prevalence currently exist for these different NSSI functions. Understanding the prevalence of NSSI functions represents a key to better understanding the phenomenology of NSSI and addressing the differing needs of the NSSI population. We conducted a systematic review and meta-analysis of the prevalence of NSSI functions in community and clinical samples. Method A literature search of electronic databases PsycINFO, Medline, and Web of Science from date of inception to March 2017 was undertaken. A pre-specified framework for categorising different functions of NSSI was used to collate data from across studies. A random-effects meta-analysis of prevalence was then undertaken on these data. Results Intrapersonal functions (66–81%), and especially those concerning emotion regulation were most commonly reported by individuals who engage in NSSI (63–78%). Interpersonal functions (e.g., expressing distress) were less common (33–56%). Limitations The review was limited to English-language articles. Reviewed articles were inconsistent in their measurement of NSSI. Inconsistency within pooled prevalence estimates was high when moderators were not accounted for. Conclusions Findings indicate that intrapersonal functions of NSSI are most common and are present for the majority of participants. This finding supports dominant emotion-regulation models of NSSI, and the use of interventions that work to improve emotion-regulation ability. However, interpersonal functions remain endorsed by a substantial portion of participants

Impulsivity and self-harm in adolescence: a systematic review

Research supports an association between impulsivity and self-harm, yet inconsistencies in methodology across studies have complicated understanding of this relationship. This systematic review examines the association between impulsivity and self-harm in community-based adolescents aged 11-25 years and aims to integrate findings according to differing concepts and methods. Electronic searches of EMBASE, MEDLINE, PsychINFO, CINAHL, PubMed and The Cochrane Library, and manual searches of reference lists of relevant reviews, identified 4,496 articles published up to July 2015, of which 28 met inclusion criteria. Twenty-four of the studies reported an association between broadly specified impulsivity and self-harm. However, findings varied according to the conception and measurement of impulsivity and the precision with which self-harm behaviours were specified. Specifically, lifetime non-suicidal self-injury was most consistently associated with mood-based impulsivity related traits. However, cognitive facets of impulsivity (relating to difficulties maintaining focus or acting without forethought) differentiated current self-harm from past self-harm. These facets also distinguished those with thoughts of self-harm (ideation) from those who acted on thoughts (enaction). The findings suggested that mood-based impulsivity is related to the initiation of self-harm, while cognitive facets of impulsivity are associated with the maintenance of self-harm. In addition, behavioural impulsivity is most relevant to self-harm under conditions of negative affect. Collectively, the findings indicate that distinct impulsivity facets confer unique risks across the life-course of self-harm. From a clinical perspective, the review suggests that interventions focusing on reducing rash reactivity to emotions or improving self-regulation and decision-making may offer most benefit in supporting those who self-harm