Absolute and Relative Short-Term Stability of Interpersonal Dependency in Suicide Attempters

Previous studies have reported an association between suicide and interpersonal dependency (IPD), but no study has examined whether IPD constitutes a state-dependent phenomenon or an enduring personality trait in this association. The aims of the present study were, firstly, to evaluate both the absolute and the relative stability of IPD as well as depression in suicide attempters and, secondly, to examine whether the relative stability of IPD was related to the depressive level rated on admission and/or at follow-up. The sample consisted of 41 suicide attempters evaluated on admission and 1 month later. The subjects filled in the Interpersonal Dependency Inventory (IDI) and the Beck Depression Inventory-II (BDI-II). The absolute and the relative stability of depression and IPD were analyzed using paired t-tests and Pearson's or intraclass correlation coefficients, respectively. The relative stability of IPD, taking into account the changes of the depressive level, was tested by two regression analyses. In the first regression analysis follow-up, the IDI scores were the dependent variable and the baseline IDI scores and BDI-II scores were the predictors. In the second regression analysis, the IDI change scores were the dependent variable and the BDI-II change scores were the predictors. Absolute and relative stability were demonstrated for IPD, whereas depression presented only relative stability. The IPD scores on admission were also significant predictors of the follow-up IPD scores after controlling for depression level. The 1-month duration of follow-up may be too brief to detect any decrease in the level of IPD. In conclusion, in contrast with the depression scores, the IPD scores presented short-term absolute and relative stability, and these results support the view that IPD is a stable personality trait in suicide attempters. The stability of IPD in suicide attempters suggests the interest of specific therapeutic approaches of this personality trait.