Our previous meta-analysis identified significant associations of SC with both NSSI and DE (Zelkowitz & Cole, 2018). Clearly, further investigation of the role of SC in both NSSI and DE is required. W1 SC will significantly predict increases in NSSI and DE at W2 after controlling for baseline levels of each behavior.
Hypothesis 3b: The Stress x SC interaction will remain significant in predicting NSSI and DE after controlling for W1 levels of each behavior. I conducted a series of path analyzes to test SC as a transdiagnostic predictor of NSSI and DE (Aim 2). I then tested SC as a predictor of NSSI and DE (examined in separate models), controlling for baseline levels of each behavior.
After controlling for SC, the correlation between NSSI and the DE composite was no longer significant. Relations between the SC x Stress interaction term and NSSI and each form of DE were nonsignificant at Wave 1.
Discussion
However, after controlling for baseline NSSI and DE behaviors and negative affect, SC remained a significant predictor of NSSI, composite DE, bingeing, and fasting at Wave 2. SC remained a significant predictor of the same outcomes after controlling for baseline behaviors and neuroticism. Finally, we documented the longitudinal effects of SC on both NSSI and DE in a university sample.
As in Study 1, Study 2 aimed to confirm the association of SC with NSSI and DE (Aim 1), test SC as a predictor of NSSI and DE (Aim 2), and test life stress as a moderator of the longitudinal association between SC and NSSI and DE (Aim 3). After controlling only for baseline DE behavior, SC significantly predicted the composite of DE, purging, and fasting at Wave 2. SC did not significantly predict NSSI before controlling for baseline behavior (Model 1), after controlling for baseline NSSI only (Model 2), or after controlling for baseline NSSI and each DE variable (Model 3).15.
As in Study 1, we noted the longitudinal reciprocal effects of NSSI and DE (although this was not an explicit goal of the study). As in Study 1, we chose to examine the main effects of SC and stress in relation to NSSI and DEs from Wave 1.
Discussion
Among the DE variables, SC remained significantly associated with only fasting and restraint after controlling for stress.
AND STUDY 2 GENERAL DISCUSSION
We further found that SC accounted for about a quarter of the (small) correlation between NSSI and DE, with results varying according to the specific DE behavior considered. It is notable that of the behaviors considered, DE SC accounted for the smallest proportion of the correlation between NSSI and purging.17. A key aim of this work was to test the longitudinal effects of SC on subsequent NSSI and DE, thereby testing an important tenet of the etiological theories proposed by Svirko and Hawton (2007) and Claes and Muehlenkamp (2014).
First, we used a composite of the SITBI and DSHI to assess NSSI in the high-risk sample. There, the authors observed significant effects of SC on subsequent NSSI among adults with a recent history of the behavior. SC also accounted for the highest proportion of the association between NSSI and any DE behavior (although the association between NSSI and bingeing itself was small and nonsignificant).
The findings of the current study support the need for further research on SC as a driver of (and potential clinical target for) binge eating. Although not an explicit goal of the study, I noted significant longitudinal effects of NSSI on subsequent fasting and binge eating in the undergraduate (but not high-risk) sample. Finally, the assessment of SC itself also reflected both a limitation and a strength of the study.
These findings, along with evidence of an overall increase in participants' SC, point to a scenario in which “the poor get [even]. The strength of the induction may have inadvertently masked differences in SC reactivity to weaker stimuli. Results from three studies showed correlations between SC, NSSI, and DE, although the proportion of the correlation between NSSI and DE accounted for by SC varied by specific DE behavior.
Two studies specifically tested the longitudinal effects of SC, providing one of the first direct tests of etiological theories of NSSI and DE as outlined by Claes and Muehlenkamp (2014) and Svirko and Hawton (2007). Rumination and emotions in non-suicidal self-injury and eating disorder behaviors: A preliminary test of the emotional cascade model. Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples.
A prospective study of the influence of the UPPS model of impulsivity on co-occurrence of bulimic symptoms and non-suicidal self-injury. A prospective test of the dual-pathway model of bulimic pathology: mediating effects of diet and negative affect.
ANALYSES BASED ON SELF-INJURIOUS THOUGHTS AND BEHAVIOR INTERVIEW, SELF-REPORT VERSION
How old were you when you first thought about engaging in NSSI? 119) How many separate times in your life have you thought about engaging in NSSI? . 120). On a scale of 0 to 4, at the worst time, how intense were your thoughts about engaging in NSSI? . 124). How intense were these thoughts on average? .. 125) Why do you think you have thoughts of engaging in NSSI?.
On a scale of 0 to 4, how much did you find engaging in NSSI a way to get rid of bad feelings?. How much have you thought about engaging in NSSI as a way to feel something because you felt numb or empty? . 128). How much have you considered joining NSZS to communicate with someone else or to gain attention? . 129).
How much did you think about engaging in NSSI to get out of doing something or to get away from others? On a scale of 0 to 4, to what extent did problems with your family lead you to have thoughts of engaging in NSSI? How much did your mental state at the time lead to these thoughts? .. 136) What percent of the time did you use drugs or alcohol when you had thoughts of engaging in NSSI?.
Before you ever thought about engaging in NSSI, how many of your friends, to your knowledge, thought about engaging in NSSI?. 139) Since the first time you thought about engaging in NSSI, how many of your friends have thought about engaging in NSSI?. Before you ever thought about engaging in NSSI, on a scale of 0 to 4, how much did your friends who thought about engaging in NSSI influence your thinking about engaging in NSSI?
On a scale of 0 to 4, how likely do you think it is that you will have thoughts of engaging in NSSI in the future?. On a scale of 0 to 4, to what extent have problems with your family led to your engaging in NSSI?. How much did your mental state at the time lead to your engaging in NSSI?.
Before you ever engaged in NSSI, how many of your friends did you know involved NSSI? Before you ever engaged in NSSI, how much did your friends who engaged in NSSI influence your involvement in NSSI, on a scale of 0 to 4? . 168) Since the first time you engaged in NSSI, how much have your friends who engaged in NSSI influenced your involvement in NSSI, on a scale of 0 to 4.
