TPC Journal Volume 11 Issue 2

224 The Professional Counselor | Volume 11, Issue 2 Psychosocial Predictors of SIB We compared the two samples on the predictor variables first by using independent sample t -tests. We found that BPD-Tx participants reported less psychological distress ( M = 2.21, SD = 0.78) than student participants: M = 2.78, SD = 0.89, t (174) = − 4.16, p < .001. The BPD-Tx participants ( M = 3.25, SD = 0.49) also reported less positive social support than student participants: M = 3.44, SD = 0.54, t (174) = − 2.26, p = .025. Lastly, BPD-Tx participants ( M = 1.22, SD = 0.43) reported more negative interactions than student participants: M = 1.07, SD = 0.43, t (174) = 2.15, p = .033. We conducted bivariate correlations between all predictor variables and the outcome variable for each sample. In the BPD-Tx sample, total SIB was positively correlated with average psychological distress ( r = .37, p = .004). In the student sample, total SIB was negatively correlated with positive social support ( r = − .18, p = .049). In both samples, average psychological distress was positively associated with negative interactions (BPD-Tx: r = .36, p = .005; student: r = .24, p = .008). No other variables were significantly correlated in either sample. Next, we conducted a multiple linear regression using total SIB as the outcome variable for both samples together. We entered seven predictors simultaneously: psychological distress, positive social support, negative interactions, sample type, and the interactions between sample type and the three other predictors. Together, these seven variables significantly predicted total SIB: F (7,168) = 5.01, p < .001, MSE = 2.33, r 2 = .17. As shown in Table 2, psychological distress ( sr 2 = .06), sample type ( sr 2 = .12), and the interaction between psychological distress and sample type ( sr 2 = .03) were each significant unique predictors of total SIB. Specifically, based on the positive β weights, more psychological distress and being in the BPD-Tx sample were both associated with higher lifetime rates of SIB. Notably, multicollinearity did not appear to be an issue in this regression given the moderate to low correlations between factors, sufficiently high tolerance values, acceptable variance inflation factor values (ranging from 1.25–1.55), and the low standard error of regression coefficients relative to their scale. Table 2 Multiple Regression Analysis Predicting Total Self-Injurious Behavior for the Whole Sample ( N = 176) CI Variable B SE B β t p sr 2 Lower Upper Psych. distress 0.57 0.16 .31 3.55 .001 .06 0.25 0.89 Pos. social support − 0.48 0.25 − .16 − 1.96 .052 .02 − 0.97 0.00 Neg. interactions − 0.26 0.30 − .07 − 0.85 .399 .003 − 0.85 0.34 Sample type 0.68 0.14 .39 4.87 < .001 .12 0.40 0.95 Psych. distress x sample 0.40 0.16 .21 2.46 .015 .03 0.08 0.71 Pos. social support x sample 0.00 0.25 .00 0.00 .997 .001 − 0.49 0.49 Neg. interactions x sample − 0.08 0.30 − .02 − 0.25 .801 .001 − 0.67 0.52 Note: Psych. = psychological; Pos. = positive; Neg. = negative; sr 2 = squared semipartial correlation. Sample type was coded so that BPD-Tx sample = 1, student sample = -1. Significant p values are in bold.