Objective
Impulsivity is a multidimensional concept that can be defined as a predisposition toward rapid, unplanned reactions to internal or external stimuli without regard to the negative consequences of these reactions to the impulsive individual or to others. Aggressiveness has been defined as an overt behaviour which intends to inflict physical damage on another individual, and can be considered pathological when it is exaggerated, persistent, or expressed out of context. Impulsivity and aggressiveness have a central role in psychopathology and clinical picture of borderline personality disorder (BPD). However, the relationship between these two dimensions is controversial and not well defined. Some authors considered impaired control of impulsivity and reactive aggressiveness as two related features of the same factor; other preferred to suppose the existence of two distinct and separate traits. The aim of the present study is to conduct a factor analysis in a sample of BPD patients, in order to investigate if impulsivity and reactive aggressiveness load on separate factors.
Methods
Sixty-eight consecutive outpatients aged 18-55 years (23 males and 45 females) who received a DSM-IV-TR diagnosis of BPD were recruited for the study. The diagnosis was confirmed with the Structured Clinical Interview for DSM-IV. The level of global symptomatology was rated with the Severity item of the Clinical Global Impression scale (CGI-S). The frequency and severity of BPD symptoms was assessed with the Borderline Personality Disorder Severity Index (BPDSI). The Barratt Impulsivity Scale-11 (BIS-11) was employed to assess the trait of impulsivity. The nature and severity of aggressive behaviour was evaluated with the Modified Overt Aggression Scale (MOAS). The Hamilton Depression Rating Scale (HAM-D) and the Hamilton Anxiety Rating Scale (HAM-A) were administered to evaluate depressive and anxiety symptoms. Correlations among the socio-demographic and clinical variables (10 items) were calculated. Principal component analysis was conducted, followed by factor analysis with varimax rotation. Correlations between the obtained scores were then estimated.
Results
Socio-demographic and clinical characteristics of the sample are reported in Table I. The principal component analysis revealed four factors accounting for 66.5% of the variance. The factor analysis after varimax rotation revealed the factor loadings shown in Table II (items with factor loadings ≥ 0.30 were deemed meaningful). The first factor (that we labelled “impulsivity”) included five items: age (-0.52), self-injuries (0.63), CGI-S (0.66), BIS-11 (0.55), and BPDSI (0.81). The second factor (labelled “reactive aggressiveness”) included five items: age (-0.47), gender (-0.60), BIS-11 (0.43), MOAS (0.84), and HAM-A (0.31). The third factor (labelled “trauma/impulsivity”) included two items: trauma (0.89) and BIS-11 (0.53). Finally, the fourth factor (labelled “anxiety/depression”) included three items: CGI-S (0.43), HAM-A (0.85), and HAM-D (0.79).
Discussion
Our findings suggest that impulsivity and reactive aggressiveness are two separate components in this sample of BPD patients and may be considered as distinct psychopathological traits. Symptoms of anxiety and depression and impulse dyscontrol behaviours related to early traumatic experiences represent the other two main components of psychopathology. The results of our study indicate that impulsivity in BPD patients is expressed in three distinct factors with different psychopathological characteristics and perhaps based on different pathogenetic pathways. The first factor appears to be characterized by a relatively pure form of impulsivity, that can be defined as a deficit to control and delay emotional reactions to stress and to evaluate the consequences of these reactions. In the second factor, impulsivity is associated to very high levels of reactive aggression. So, we can suppose that a poor control of impulsive behaviours in these patients is a predisposing condition to overt aggressive actions against others, representing the outstanding characteristic of clinical picture. The third factor presents a peculiar association of impulsivity and early onset traumas. Hence, the deficit in controlling impulsive reactions can be supposed to constitute an effect of personality abnormalities due to childhood traumatic experiences. Of course, a better characterization of these three factors and of the fourth factor, characterized by non-specific anxiety and depressive symptoms, will be possible only after replicating these findings in larger samples with more complete assessment of clinical and biological correlates.