Friday, June 7, 2013

Identity Disturbance in Borderline Personality Disorder: An Empirical Investigation – Part 3

We’re getting there. So let’s move along! 


Identity Disturbance in Borderline Personality Disorder: An Empirical Investigation – Part 3

Tess Wilkinson-Ryan, A.B.; Drew Westen, Ph.D.


RESULTS

The patients described by the clinician respondents ranged in age from 18 to 66 years. We initially intended simply to compare patients with borderline personality disorder (N=34) to patients without the disorder. However, when we examined the data, we found that the nonborderline group (N=61) included 20 patients diagnosed by their clinicians with personality disorders other than borderline personality disorder, which allowed us to test hypotheses more conservatively. Although the reliability of the "other personality disorders" category is unknown, we were able to assess whether these patients differed in their general social adjustment and level of psychopathology from the subjects with no personality disorder. In any event, diagnostic unreliability and smaller group sizes would foster type II, rather than type I, errors; thus, any findings that emerged with this three-group comparison would be very conservative. Given the preliminary nature of this study, which constitutes the first (to our knowledge) systematic effort to explore the precise nature of identity disturbance in patients with borderline personality disorder, this conservatism seemed warranted. As a secondary analysis, we ran analyses with just two groups (borderline personality disorder versus no borderline personality disorder). The results were the same or stronger in all cases, so here we report the more conservative findings.

In short, they took the safe approach to get the most accurate comparison between Borderline and Non-Borderline groups.

As expected, gender ratios differed somewhat among the groups. In the borderline personality disorder group, 82.4% of subjects (N=28) were female, which resembles the gender ratio for this disorder in the population (approximately 75%, according to DSM-IV). Half of the subjects with other personality disorders were female; the corresponding percentage in the no personality disorder group was 65.9% (N=27). Thus, we used sex as a covariate in subsequent analyses.

Diagnostic Validity

To distinguish patients with borderline personality disorder from other patients, we first asked clinicians to fill in an axis II diagnosis. As a validity check, we then asked them to 1) indicate whether each of the nine DSM-IV criteria for borderline personality disorder was present or absent, 2) rate the extent to which the patient showed symptoms of borderline personality disorder as well as symptoms of each of the other axis II personality disorders, and 3) report on level of functioning (Global Assessment of Functioning scores, employment history, and number and quality of peer relationships).

Data relevant to diagnostic reliability for the 95 subjects are presented in t2. To be diagnosed with borderline personality disorder, a patient must manifest at least five of the nine DSM-IV criteria. In this study, patients diagnosed with borderline personality disorder fulfilled an average of 7.4 criteria. Patients with other personality disorders or no personality disorder averaged fewer than five. Differences among these means were statistically significant. Similar findings emerged when we compared the severity ratings of each borderline personality disorder criterion.

            Standard DSM you have BPD, stand you don’t have BPD.

To compare personality pathology, we averaged all the personality disorder symptom ratings for the three groups for each of the 10 personality disorders, which produced a composite index of the extent to which patients in each group had personality disorder symptoms of any kind. As expected, the borderline personality disorder group had the highest mean ratings, followed by the subjects with other personality disorders and then those with no personality disorder. The differences among these means were significant. As a specific validity check on the diagnosis of "other personality disorders," we then recomputed these means excluding borderline personality disorder symptom ratings. Post hoc comparisons revealed significant differences but only between the no personality disorder group on the one hand and both personality disorder groups on the other. Thus, both personality disorder groups appeared to score higher on personality disorder characteristics than the no personality disorder group, and the borderline personality disorder group was specifically higher than both other groups on borderline characteristics.

This is all about comparing averages if you’re interested in averages. BPD “wins” on having more disordered traits, yay us, compared to people without BPD and people with “other personality disorders”.

Level of functioning variables also provided support for diagnostic reliability. Mean scores on the Global Assessment of Functioning were significantly different for the three groups as were the quality of peer relationships and the number of close relationships; employment stability, however, did not differ.           

One peculiarity of the data did emerge: 19.7% of the patients without borderline personality disorder (N=12, split roughly evenly between the subjects with other personality disorders and those with no personality disorder) fulfilled five borderline criteria. We suspect this reflects both the high comorbidity of borderline personality disorder with nearly all other personality disorders and the tendency of clinicians to prioritize axis II diagnoses, giving such diagnoses as "narcissistic personality disorder with borderline features". We addressed this in two ways. First, in line with our strategy of minimizing type I errors and maximizing conservatism of the findings, we kept patients in the diagnostic categories to which clinicians assigned them. If some subjects with no personality disorder really met borderline personality disorder criteria, that would reduce mean differences between the two groups, not overestimate them. Second, as planned, we supplemented categorical analyses with continuous analyses, with number of borderline criteria as the dependent variable, and used multiple regression to predict the number of borderline personality disorder criteria from identity factor scores. Thus, our findings are applicable not only to categorical but to dimensional analyses of borderline personality disorder symptoms.



There is no way you’re going to be classified as having BPD in this study if you don’t actually have it. Really? It’s true. They’re being super stringent.


The prevalence and confirmation of abuse history for the patients are reported in t1. Of the 24 clinicians who marked "Yes" on the sexual abuse question, all reported confirmation from at least one outside source. Four clinicians who completed this section marked the sexual abuse history as "Unsure." None of these four patients entered treatment with clear, conscious memories or documenting evidence of abuse. The data thus suggest that clinicians were using sensible (although of course not infallible) algorithms in determining degree of likelihood of sexual abuse history.

Hmmm. I wonder if they were correcting for sexual abuse in childhood, adolescence, or adulthood. I have a history of sexual abuse, but not in childhood. My BPD symptoms were already full blown by the time that happened. Either way, I’m sure it has a significant effect. I know it affected me.

To ascertain the extent to which our measure of identity disturbance was really capturing the construct it was designed to assess, we used clinicians’ ratings of whether the identity disturbance criterion from DSM-IV was present or absent, which divided patients into two groups. We then compared the mean ratings for each identity disturbance item for these two groups in an effort to assess the extent to which our items were capturing the same construct clinicians classify as identity disturbance. Twenty-eight of the 35 items significantly discriminated between patients with and without identity disturbance at the 0.05 level (conservatively using two-tailed tests, even though predictions were directional), which indicates that our items did in fact address identity disturbance as clinicians conceptualize it.

            Yay the tests work!

The items that did not predict identity disturbance tended to describe unusual phenomena with low base rates, such as "patient ‘displays’ identity in ways that appear unusual or deviant (e.g., multiple tattoos, piercings, highly peculiar hair style or coloring)," on which most subjects received a rating of "1." Although deviant appearance may be an indicator of identity disturbance in the general (or psychiatric) population, our study group size may not have been large enough to detect this.

I like this quite a bit actually. Tattoos, piercings, crazy hair, and things like that did NOT indicate identity disturbance! That’s absolutely fabulous. Well, not really anyways.
           
Distinguishing Identity Disturbance in Borderline Personality Disorder: Item, Factor, and Construct Analyses

To examine the nature of identity disturbance in borderline personality disorder, as a first step we compared means for each item for patients with borderline personality disorder with means for each of the other two diagnostic groupings (t3). To be conservative, we only considered those items that distinguished borderline personality disorder from both of the other groups as clear markers of borderline identity disturbance, again by using two-tailed tests despite directional hypotheses. Thirty-two of the 35 items distinguished subjects with borderline personality disorder from those with no personality disorders; of these, 17 items also distinguished subjects with borderline personality disorder from those with other personality disorders. Thus, the data suggest that robust differences do exist between patients with borderline personality disorder and other patients, whether or not they have a personality disorder. It is important to note that the data did not support potential concerns about clinician response bias. Respondents did not simply give high ratings to all 35 indicators of identity disturbance if they had diagnosed the patient with borderline personality disorder and give low ratings otherwise; over half the items that discriminated patients with borderline personality disorder from those with no personality disorder did not discriminate patients with borderline personality disorder from those with other personality disorders, who clinicians clearly identified as nonborderline.

To discern whether identity disturbance was a unitary or multidimensional construct they went on to determine a variety of factors.

1. The first factor was role absorption, in which patients appeared to absorb themselves in, or define themselves in terms of, a specific role, cause, or unusual group.

2. The second factor, painful incoherence, reflected patients’ subjective experience and concern about a lack of coherence.

3. The third factor, inconsistency, was characterized less by subjective than objective incoherence (i.e., did not imply distress).

4. The fourth factor was lack of commitment (i.e., to jobs or values).

The factors all showed high internal consistency, with the following reliabilities (coefficient alpha): factor 1=0.85, factor 2=0.90, factor 3=0.88, factor 4=0.82. t4 describes the items that loaded above 0.50 on each factor.

Basically the closer to 1 = closer to 100%. This is all mostly about data analysis if you’re interested.

To see whether patients diagnosed with borderline personality disorder would differ from other patients on these four dimensions of identity disturbance, we compared the means of the three groups by using a one-way analysis of variance (ANOVA) for an omnibus F, and then tested specific hypotheses by using contrast analysis. The ANOVA showed a significant difference between the three groups on the first (F=3.87, df=2, 92, p=0.02), second (F=16.14, df=2, 92, p<0.001), and third (F=4.82, df=2, 92, p=0.01) factors and approached significance on the fourth (F=2.65, df=2, 92, p=0.08).

The more important analysis is the contrast analysis, which asks more focused questions than the omnibus F. We tested three competing hypotheses for each factor, specified in advance. Borderline patients would score higher than the other two groups, who would not differ from each other (contrast weights: 2, –1, –1). 2) Scores for the three groups would be linearly related, such that borderline personality disorder patients would have the highest scores, followed by patients with other personality disorders and then those with no personality disorder (contrast weights: 1, 0, –1). 3) Mean scores would follow the same order as in the previous contrast but with a larger mean difference between patients with borderline personality disorder and those with other personality disorders than between patients with other personality disorders and those with no personality disorders (contrast weights: 4, –1, –3). The second, linear model, tended to be the most robust, revealing predicted differences among all three groups. These differences are all the more striking given the limited diagnostic reliability data for the group with other personality disorders. The results of these analyses are detailed in t5. (For simplicity, we only report the first two contrasts in each case, because contrasts two and three were largely redundant.)

Analyzing the data a second way, we used multiple regression to predict borderline pathology, measured dimensionally by the number of DSM-IV borderline symptoms, from patients’ scores on the four identity factors. The four factors together (R=0.71) accounted for 50.2% of the variance, with the first three factors contributing significantly to the variance (p<0.05) and the fourth showing a trend (p=0.10).

Basically no matter which way they analyzed the data people with BPD had much higher degrees of identity disturbance than people with “other personality disorders” and as much as four times the degree of identity disturbance as those with no personality disorder.


Disentangling Borderline Personality Disorder and Sexual Abuse

The data thus far indicate that patients with borderline personality disorder do indeed differ from both subjects with other personality disorders and those with no personality disorder in multiple dimensions of identity disturbance. What is not indicated is whether, or to what extent, those findings reflect the greater incidence of sexual abuse in patients with borderline personality disorder (or gender differences, given the higher prevalence of borderline personality disorder among women).

We thus wanted to examine the extent to which a diagnosis of borderline personality disorder contributed to factor scores independent of a patient’s gender and sexual abuse history. To accomplish this, we used multiple regression to assess the predictive value of gender (dummy coded 0=male, 1=female), sexual abuse history (coded 0=no, 1=unsure, 2=yes), and diagnosis (borderline personality disorder=1, no borderline personality disorder=0) for each factor, entering gender and sexual abuse history in the first step and diagnosis in the second.

Sexual abuse history was correlated to varying degrees with each factor; however, in all cases, the model that included borderline personality disorder diagnosis was significantly more predictive than the model that included only patient gender and sexual abuse history (t6). For the first factor, role absorption, gender and sexual abuse contributed substantially less than the borderline diagnosis to the predictive power of the model. The second factor, characterized by painful feelings of identity incoherence, was highly correlated with sexual abuse history, although inclusion of borderline personality disorder diagnosis significantly improved the model’s predictive power. For the other two factors, patient gender and sexual abuse history did not account for enough variance to reach significance. The fourth factor was best predicted by the model that included borderline personality disorder diagnosis, but this model did not account for a significant amount of the variance.

In a second set of analyses, we assessed the relationship between sexual abuse and severity of the disorder (total number of symptoms). A history of sexual abuse predicted a higher likelihood of borderline features (r=0.49, df=90, p<0.001). A regression model including patient gender and sexual abuse (R=0.51) accounted for 25.6% of the total variance on number of symptoms present (F=12.75, df=2, 74, p=0.001). In contrast, a model including patient gender, sexual abuse history, and the four identity factors (R=0.73) accounted for 53.1% of the total variance (F=13.20, df=6, 70, p<0.001); this change was highly significant (F=10.24, df=4, 70, p<0.001). Comparable findings emerged when we used gender, sexual abuse, and the four identity factors to predict the presence or absence of the borderline diagnosis. The combined model (R=0.73) explained 53.1% of the variance (F=13.20, df=6, 70, p<0.001). The same was true when we used these variables to predict number of borderline symptoms excluding the identity disturbance criterion. Gender and sexual abuse alone in this analysis explained 25.0% of the variance, whereas adding the identity variables (R=0.67) explained an additional 20.0% (F=15.20, df=4, 75, p<0.001), a highly significant change (F=7.61, df=4, 70, p<0.001).

Basically in this study they compared Sexual Abused to a number of factors like BPD, Gender, Identity, etc; on their own, and combined and compared them to see where sexual abuse had significant impacts. A history of sexual abuse predicted a higher likelihood of borderline features and a higher severity of borderline features. That shouldn’t be a surprise to many of us. It was also found that when they combined gender, sexual abuse history and identity issues over 50% were impacted significantly. Comparable findings also emerged for distinguishing a borderline diagnosis; that is with gender, sexual abuse history, and identity issues. Something to keep an eye on I’d say.

           
Identity Disturbance and Borderline Subtypes

As an exploratory analysis, we followed up on findings of two recent studies that isolated two distinct types of patients currently diagnosed with borderline personality disorder, one with more dysphoric features and the other with more histrionic features. The first type (emotionally dysregulated) includes patients who have intense, painful, and poorly regulated emotions that they attempt to escape by using various maladaptive affect-regulatory strategies. The second (histrionic) type have emotions that are intense and dramatic but not very troubling to them; for these patients, dramatic emotions may even be self-defining.

To examine identity disturbance in patients who approximate the emotionally dysregulated type, we examined the partial correlations between ratings of borderline personality disorder and each identity disturbance factor, holding constant ratings of the extent to which the patient had histrionic features. (To maximize the comparability of dimensional diagnoses of borderline personality disorder and histrionic personality disorder, we used clinicians’ 1–7 ratings of each.) As predicted, this analysis indicated a very strong relationship (r=0.58, df=70, p<0.001) between severity of borderline personality disorder and the second factor, painful incoherence, after controlling for histrionic features. The only other significant partial correlation was with the fourth factor, lack of commitment (r=0.24, df=70, p=0.05).

Conversely, to examine identity disturbance in patients who approximate the histrionic type, we examined the partial correlations between ratings of histrionic personality disorder and each identity factor, holding constant borderline personality disorder ratings. For the first factor, role absorption, the partial correlation with the histrionic rating was significant (r=0.24, df=82, p=0.03). Strikingly, the second factor, which correlated so strongly with borderline personality disorder, showed a slightly negative correlation with histrionic ratings (r=–0.07, df=82, p=0.50). The last two factors correlated slightly positively with the histrionic rating (r=0.19, df=82, p=0.08; and r=0.13, df=82, p=0.28, respectively. Thus, some elements of identity disturbance appear more closely associated with histrionic than with borderline features, particularly role absorption, and, secondarily, inconsistency.

On the one hand I feel I like that they’re exploring more than one expression of BPD but I think they’re sort of missing the point at the same time. Personally I could be both dysphoric and histrionic at times, especially when I was younger. In fact it was either one or the other. I was either in intense pain or incredibly angry and moody… or I was really attention-seeking and involved in my relationships and sexually involved and the life of the party. Being Borderline is rarely so cleanly cut. So it’s not surprising that they they would still have a correlation with the control factor of the dysphoric or histrionic feature for the other group. I will say though that even when I was in my more histrionic phases I did have a very self-loathing streak. I don’t know if that’s present in people with histrionic personality disorder. I was trying to escape my pain which they were definitely spot on for.


I know this post was a lot of Analysis and numbers and data collection and it’s hard to wade through. Next is the Discussion! That’s the good stuff! 

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