Using Exploratory Data Mining to Identify Important Correlates of Nonsuicidal Self-Injury Frequency

OBJECTIVE

Non-suicidal self-injury (NSSI) has been linked to many adverse outcomes, with more frequent NSSI increasing the likelihood of impairment, severity, and more serious self-harming behavior (e.g., suicidality; Andover & Gibb, 2010; Darke et al., 2010). Despite the determined importance of NSSI frequency in understanding the severity of one's behavior, there is still a need to identify which constructs may be influential in predicting frequency. The current study aimed to fill this gap by identifying which correlates are most important in relation to NSSI frequency through two exploratory data mining methods.

METHOD

Seven hundred twelve undergraduate students with a history of NSSI completed self-report measures of NSSI behavior, suicidality, cognitive-affective deficits, and psychopathology symptomology.

RESULTS

Both exploratory data mining methods, lasso regression and random forests, demonstrated number of NSSI methods to be the factor with the most importance in relation to lifetime NSSI frequency. Once this variable was removed, suicide plan and depressive symptomology were significant correlates across methods.

CONCLUSIONS

The current findings support the literature between NSSI frequency and NSSI methods, but also implicate suicide plans, an often-overlooked factor, and depression in NSSI severity.

Is the first cut really the deepest? Frequency and recency of nonsuicidal self-injury in relation to psychopathology and dysregulation

Research on nonsuicidal self-injury (NSSI) has moved beyond examination of factors that associate with the mere presence or absence of the behavior, and into more nuanced examination of which discrete features of NSSI behavior relate to pathology. This study examined two features of NSSI, frequency of occurrence and recency, as cross-sectional predictors of psychopathology in a large community sample of adults with a history of NSSI (N = 315). Results of 2 × 2 factorial ANOVAs testing the interactive effects of NSSI frequency (clinical, subclinical) and recency (current, past) revealed that current NSSI was consistently associated with poorer emotional and behavioral health (e.g., greater symptoms of depression, panic, and anxiety, worse emotion regulation, greater alcohol misuse). Results for NSSI frequency were more variable, though preliminary evidence suggested significant interactions of current NSSI and clinical frequency on emotion dysregulation, general anxiety, and panic. Possible clinical and empirical implications of the NSSI disorder frequency criteria proposed in DSM-5 are discussed.