Journal of Personality Disorders, 28, 2014, 169 © 2014 The Guilford Press
DOES BORDERLINE PERSONALITY DISORDER MANIFEST ITSELF DIFFERENTLY IN PATIENTS WITH BIPOLAR DISORDER AND MAJOR DEPRESSIVE DISORDER? Mark Zimmerman, MD, Theresa A. Morgan, PhD, Diane Young, PhD, Iwona Chelminski, PhD, Kristy Dalrymple, PhD, and Emily Walsh, BA
Perugi and colleagues (2013) recently reported that some features of borderline personality disorder (BPD) significantly predicted a diagnosis of bipolar disorder among depressed patients. They interpreted these findings as indicating that some BPD criteria are nonspecific and are indicators of bipolar disorder rather than BPD, whereas other criteria are more specific to BPD. In the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, the authors tested the hypothesis that BPD presents itself differently in psychiatric outpatients diagnosed with bipolar disorder or major depressive disorder. The authors found that the patients with bipolar disorder were significantly more likely to report impulsive behavior and transient dissociation. No criterion was significantly more common in the BPD patients with MDD. The authors therefore do not consider the BPD criteria to be nonspecific with regard to the distinction between BPD and bipolar disorder.
The relationship between borderline personality disorder (BPD) and bipolar disorder has been the subject in much research and theoretical discourse. Several literature reviews have considered whether BPD should be considered a bipolar spectrum disorder, and these reviews have reached contradicting conclusions (Antoniadis, Samakouri, & Livaditis, 2012; Belli, Ural, & Akbudak, 2012; Coulston, Tanious, Mulder, Porter, & Malhi, 2012; Dolan-Sewell, Krueger, & Shea, 2001; Paris, 2004; Smith, Muir, & Blackwood, 2004; Sripada & Silk, 2007). The most studied question of the bipolar disorder-BPD relationship is the comorbidity between the two disorders. A comprehensive review of two This article was accepted under the editorship of Robert F. Krueger and John Livesley. From the Department of Psychiatry and Human Behavior, Brown Medical School, and the Department of Psychiatry, Rhode Island Hospital, Providence (M. Z., T. A. M., D. Y., I. C. K. D., E. W.). Address correspondence to Mark Zimmerman, MD, 146 West River St., Providence, RI 02904; E-mail: [email protected]
1
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dozen studies of the comorbidity between the two disorders found that approximately 20% of patients with BPD were also diagnosed with bipolar disorder (bipolar I or bipolar II) (Zimmerman & Morgan, 2013). Likewise, approximately 20% of bipolar II patients were diagnosed with BPD, although only 10% of bipolar I patients were diagnosed with BPD. Recently, Perugi and colleagues (2013) examined which BPD criteria were associated with a diagnosis of bipolar disorder in a large sample of depressed patients. They found that unstable relationships, affective instability, impulsivity, and excessive anger significantly predicted a diagnosis of bipolar disorder, whereas chronic emptiness predicted the absence of bipolar disorder. They interpreted their findings as indicating that some BPD criteria are nonspecific and are indicators of bipolar disorder rather than BPD, whereas other criteria are more specific to BPD. This suggests that BPD may present itself differently in patients with bipolar and nonbipolar depression. That is, bipolar patients with BPD are more often characterized by affective instability, anger, and impulsivity, whereas nonbipolar depressed patients with BPD are more often characterized by fears of separation, chronic emptiness, and selfinjurious behavior. In the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, we tested the hypothesis that BPD presents itself differently in psychiatric outpatients diagnosed with bipolar disorder or major depressive disorder.
METHOD The Rhode Island MIDAS project represents an integration of research methodology into a community-based outpatient practice affiliated with an academic medical center (Zimmerman, 2003). A comprehensive diagnostic evaluation is conducted upon presentation for treatment. This private practice group predominantly treats individuals with medical insurance (including Medicare but not Medicaid) on a fee-for-service basis, and it is distinct from the hospital’s outpatient residency training clinic, which predominantly serves lower income, uninsured, and medical assistance patients. Data on referral source were recorded for the last 1,999 patients enrolled in the study. Patients were most frequently referred from primary care physicians (29.7%), psychotherapists (17.4%), and family members or friends (17.7%). The Rhode Island Hospital institutional review committee approved the research protocol, and all patients provided informed, written consent. The sample examined in the present report was derived from the 3,800 psychiatric outpatients evaluated with semistructured diagnostic interviews. Patients were interviewed by a diagnostic rater who administered a modified version of the Structured Clinical Interview for DSM-IV (SCID) (First, Spitzer, Gibbon, & Williams, 1995) and the borderline personality disorder section of the Structured Interview for DSM-IV Personality (SIDP-
jpd169.indd 2
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BPD, BIPOLAR DISORDER, AND MAJOR DEPRESSIVE DISORDER3
IV) (Pfohl, Blum, & Zimmerman, 1997). The present report is based on the 277 patients diagnosed with BPD who were also diagnosed with bipolar depression (n = 46) or major depressive disorder (n = 231). The 277 patients included 74 (26.7%) men and 203 (73.3%) women who ranged in age from 17 to 68 years (mean = 32.97, SD = 9.85). Approximately one quarter of the subjects were married (24.2%, n = 67); the remainder were single (44.4%, n = 123), divorced (16.2%, n = 45), separated 5.1%, n = 14), widowed (0.7%, n = 2), or living with someone as if in a marital relationship (9.4%, n = 26). Approximately two-thirds of the patients attended school beyond high school (62.4%, n = 173), although only one sixth graduated from a 4-year college (15.2%, n = 42). The racial composition of the sample was 85.2% (n = 236) White, 7.2% (n = 20) Black, 4.0% (n = 11) Hispanic, 0.7% (n = 2) Asian, and 2.9% (n = 8) from another or a combination of these racial backgrounds. The diagnostic raters were highly trained and monitored throughout the project to minimize rater drift. The diagnostic raters included PhD-level psychologists and research assistants with college degrees in the social or biological sciences. Research assistants received 3 to 4 months of training during which they observed at least 20 interviews, and they were observed and supervised in their administration of more than 20 evaluations. Psychologists observed only five interviews, and they were observed and supervised in their administration of 15 to 20 evaluations. During the course of training, the senior author met with each rater to review the interpretation of every item on the SCID. In addition, during training every interview was reviewed on an item-by-item basis by the senior rater, who observed the evaluation, and by the senior author, who reviewed the case with the interviewer. At the end of the training period, the raters were required to demonstrate exact, or near exact, agreement with a senior diagnostician on five consecutive evaluations. Throughout the MIDAS project, ongoing supervision of the raters consisted of weekly diagnostic case conferences involving all members of the team. In addition, every case was reviewed by the senior author. Reliability was examined in 65 patients. A joint-interview design was used in which one rater observed another conducting the interview, and both raters independently made their ratings. Of relevance to the present report, the reliabilities for diagnosing MDD (k = 0.90) and bipolar disorder (k = 0.75) were good. The reliability for diagnosing BPD (k = 1.0) was excellent, as was the reliability of the BPD dimension (intraclass correlation coefficient = 0.96).
STATISTICAL ANALYSIS T tests were used to compare the groups on continuously distributed variables. Categorical variables were compared by the chi-square statistic, or by Fisher’s Exact Test if the expected value in any cell of a 2 × 2 table was less than 5.
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ZIMMERMAN ET AL. TABLE 1. Frequency of DSM-IV Borderline Personality Disorder Criteria in Psychiatric Outpatients with Bipolar Disorder or Major Depressive Disorder
DSM-IV Borderline Criteria Abandonment Fear Interpersonal Instability Identity Disturbance Impulsive Behavior Suicidal/Self-Injurious Behavior Affective Instability Chronic Emptiness Excessive Anger Transient Dissociation
Bipolar Disorder (n = 46)
Major Depressive Disorder (n = 231)
%
n
%
n
χ2
p
34.8 73.9 73.9 80.4 54.3 89.1 84.8 82.6 67.4
16 34 34 37 25 41 39 38 31
34.6 77.9 71.4 63.2 52.8 93.1 81.4 84.8 50.6
80 180 165 146 122 215 188 196 117
0.0 0.4 0.1 5.1 0.0 0.9 0.3 0.1 4.3
ns ns ns .02 ns ns ns ns .04
RESULTS The rate of BPD was not significantly different in patients with bipolar I and bipolar II disorder (23.5% vs. 26.1%, χ2 = 0.15, ns), and there was no difference in the mean number of BPD criteria in the two groups (6.7 ± 1.7 vs. 6.2 ± 1.0, t = 1.11, ns). Likewise, there was no difference in the frequency of any of the nine BPD criteria. Consequently, we combined the bipolar I and bipolar II groups and compared the combined group to the patients with MDD. The mean number of criteria was not significantly different in the BPD patients with bipolar disorder and MDD (6.4 ± 1.3 vs. 6.1 ± 1.1, t = –1.52, ns). The patients with bipolar disorder were significantly more likely to report impulsive behavior and transient dissociation (Table 1). No criterion was significantly more common in the BPD patients with MDD. DISCUSSION The present results provide partial support for the hypothesis that BPD presents differently in patients with bipolar versus nonbipolar depression. Consistent with the findings of Perugi et al. (2013), impulsivity was more common in bipolar than nonbipolar depressed patients. However, in contrast to their findings, the bipolar patients more often reported stressrelated dissociative/paranoid reactions, and there was no difference in affective instability, unstable interpersonal relationships, or anger. Some authors have suggested that BPD belongs on the bipolar spectrum because of the high degree of comorbidity between the disorders and the similarity of some phenomenological features, such as affective instability, impulsivity, and irritability (Akiskal, 2004; Belli et al., 2012; Smith et al., 2004; Wilson et al., 2007). While we found greater impulsivity in BPD patients with bipolar disorder, other features that might reflect bipolarity were not more frequent in the bipolar patients. We therefore do not
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BPD, BIPOLAR DISORDER, AND MAJOR DEPRESSIVE DISORDER5
consider the BPD criteria to be nonspecific with regard to the distinction between BPD and bipolar disorder. The vast majority of patients with BPD have a comorbid mood disorder (Zanarini, Gunderson, & Frankenberg, 1989; Zimmerman & Mattia, 1999). In patients with BPD, it is important to distinguish between MDD and bipolar disorder because this has treatment implications regarding pharmacological management. The present findings suggest that in depressed patients with BPD, the specific criteria met do not provide much guidance in distinguishing between bipolar and nonbipolar disorder. Thus, in patients with MDD, neither the presence of BPD nor the presence of particular BPD features justifies the prescription of mood stabilizer medications because of presumed occult bipolarity. To be sure, mood stabilizers and atypical antipsychotic medications may be beneficial for some features of BPD (Vita, De Peri, & Sacchetti, 2011). However, given the nonspecificity of most psychotropic agents, this does not indicate that the medicationresponsive features of BPD imply a bipolar disorder diathesis. While not the focus of this article, this is the first study to directly compare the frequency of BPD in patients with bipolar I and bipolar II disorder. We found no difference between bipolar I and bipolar II patients in the rate of BPD. This finding is in contrast to recent reviews that found a higher rate of BPD in patients with bipolar II disorder than bipolar I disorder (Paris, Gunderson, & Weinberg, 2007; Zimmerman & Morgan, 2013). In these reviews, the rate of BPD in the diagnostic subtypes was computed across separate studies that focused on patients with only one form of bipolar disorder. Perhaps the discrepancy between our findings and those of the literature reviews was related to the methods of ascertaining the studies’ samples. Our results were derived from a clinical epidemiological sample in which patients were evaluated without regard to their presenting complaint or diagnosis. Thus, we did not select cases that were prototypical patients with bipolar disorder. Studies limited to bipolar I or bipolar II disorder may be more likely to select clear-cut representations of the disorder. More studies are needed with broad inclusion that directly compare patients with bipolar I versus bipolar II disorder to clarify the potential impact of sample selection procedures. In the present study, we followed the Diagnostic and Statistical Manual of Mental Disorders, 4th edition’s (DSM-IV; American Psychological Association, 1994) categorical approach toward diagnosis. To be sure, the distribution of pathology of personality disorders more closely follows a dimensional than a categorical model. Some of the overlap between bipolar disorder and BPD can be partly explained by phenomenological similarities in some of the manifestations of each disorder, the continuous distribution of features of each disorder, and the arbitrariness in the selection of thresholds to denote whether a disorder is present or absent. A limitation of the study is that it was conducted in a single outpatient practice in which the majority of patients were white, female, and had health insurance. Replication of the results in samples with different de-
jpd169.indd 5
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ZIMMERMAN ET AL.
mographic characteristics is warranted. While the generalizability of any single site study is limited, a strength of the study is that the patients were unselected with regard to meeting any inclusion or exclusion criteria. Moreover, a strength of the study is the use of highly trained interviewers who diagnosed BPD and mood disorders with high reliability. We used the DSM-IV criteria to diagnose major depressive disorder and bipolar disorder. The DSM-IV criteria for bipolar disorder have been criticized for being too narrow (Zimmerman, 2012). The overlap between bipolar disorder and the BPD criteria might be greater when a broader definition of bipolar disorder is used (Perugi et al., 2013).
REFERENCES Akiskal, H. S. (2004). Demystifying borderline personality: Critique of the concept and unorthodox reflections on its natural kinship with the bipolar spectrum. Acta Psychiatrica Scandinavica, 110, 401–407. American Psychological Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author. Antoniadis, D., Samakouri, M., & Livaditis, M. (2012). The association of bipolar spectrum disorders and borderline personality disorder. Psychiatric Quarterly, 83, 449–465. Belli, H., Ural, C., & Akbudak, M. (2012). Borderline personality disorder: Bipolarity, mood stabilizers and atypical antipsychotics in treatment. Journal of Clinical Medicine Research, 4, 301– 308. Coulston, C. M., Tanious, M., Mulder, R. T., Porter, R. J., & Malhi, G. S. (2012). Bordering on bipolar: The overlap between borderline personality and bipolarity. Australian and New Zealand Journal of Psychiatry, 46, 506–521. Dolan-Sewell, R., Krueger, R. F., & Shea, M. T. (2001). Co-occurrence with syndrome disorders. In W. J. Livesley (Ed.), Handbook of personality disorders: Theory, research and treatment (pp. 84–104). New York, NY: Guilford Press. First, M. B., Spitzer, R. L., Gibbon, M., & Williams, J. B. W. (1995). Structured Clinical Interview for DSM-IV Axis I Disorders-Patient edition (SCID-I/P, version 2.0). New York, NY: Biometrics
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Research Department, New York State Psychiatric Institute. Paris, J. (2004). Borderline or bipolar? Distinguishing borderline personality disorder from bipolar spectrum disorders. Harvard Review of Psychiatry, 12, 140– 145. Paris, J., Gunderson, J., & Weinberg, I. (2007). The interface between borderline personality disorder and bipolar spectrum disorders. Comprehensive Psychiatry, 48, 145–154. Perugi, G., Angst, J., Azorin, J. M., Bowden, C., Vieta, E., & Young, A. H. (2013). The bipolar-borderline personality disorders connection in major depressive patients. Acta Psychiatrica Scandinavica, 128, 376–383. Pfohl, B., Blum, N., & Zimmerman, M. (1997). Structured Interview for DSMIV Personality. Washington, DC: American Psychiatric Press, Inc. Smith, D. J., Muir, W. J., & Blackwood, D. H. (2004). Is borderline personality disorder part of the bipolar spectrum? Harvard Review of Psychiatry, 12, 133–139. Sripada, C. S., & Silk, K. R. (2007). The role of functional neuroimaging in exploring the overlap between borderline personality disorder and bipolar disorder. Current Psychiatry Reports, 9, 40– 45. Vita, A., De Peri, L., & Sacchetti, E. (2011). Antipsychotics, antidepressants, anticonvulsants, and placebo on the symptom dimensions of borderline personality disorder: A meta-analysis of randomized controlled and open-
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BPD, BIPOLAR DISORDER, AND MAJOR DEPRESSIVE DISORDER7 label trials. Journal of Clinical Psychopharmacology, 31, 613–624. Wilson, S. T., Stanley, B., Oquendo, M. A., Goldberg, P., Zalsman, G., & Mann, J. J. (2007). Comparing impulsiveness, hostility, and depression in borderline personality disorder and bipolar II disorder. Journal of Clinical Psychiatry, 68, 1533–1539. Zanarini, M. C., Gunderson, J. G., & Frankenberg, F. R. (1989). Axis I phenomenology of borderline personality disorder. Comprehensive Psychiatry, 30, 149–156. Zimmerman, M. (2003). Integrating the assessment methods of researchers in routine clinical practice: The Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) proj-
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ect. In M. First (Ed.), Standardized evaluation in clinical practice (Vol. 22, pp. 29–74). Washington, DC: American Psychiatric Publishing, Inc. Zimmerman, M. (2012). Would broadening the diagnostic criteria for bipolar disorder do more harm than good? Implications from longitudinal studies of subthreshold conditions. Journal of Clinical Psychiatry, 73, 437–443. Zimmerman, M., & Mattia, J. I. (1999). Axis I diagnostic comorbidity and borderline personality disorder. Comprehensive Psychiatry, 40, 245–252. Zimmerman, M., & Morgan, T. A. (2013). The relationship between borderline personality disorder and bipolar disorder. Dialogues in Clinical Neuroscience, 15, 79–93.
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DOES BORDERLINE PERSONALITY DISORDER MANIFEST ITSELF DIFFERENTLY IN PATIENTS WITH BIPOLAR DISORDER AND MAJOR DEPRESSIVE DISORDER? Mark Zimmerman, MD, Theresa A. Morgan, PhD, Diane Young, PhD, Iwona Chelminski, PhD, Kristy Dalrymple, PhD, and Emily Walsh, BA
Perugi and colleagues (2013) recently reported that some features of borderline personality disorder (BPD) significantly predicted a diagnosis of bipolar disorder among depressed patients. They interpreted these findings as indicating that some BPD criteria are nonspecific and are indicators of bipolar disorder rather than BPD, whereas other criteria are more specific to BPD. In the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, the authors tested the hypothesis that BPD presents itself differently in psychiatric outpatients diagnosed with bipolar disorder or major depressive disorder. The authors found that the patients with bipolar disorder were significantly more likely to report impulsive behavior and transient dissociation. No criterion was significantly more common in the BPD patients with MDD. The authors therefore do not consider the BPD criteria to be nonspecific with regard to the distinction between BPD and bipolar disorder.
The relationship between borderline personality disorder (BPD) and bipolar disorder has been the subject in much research and theoretical discourse. Several literature reviews have considered whether BPD should be considered a bipolar spectrum disorder, and these reviews have reached contradicting conclusions (Antoniadis, Samakouri, & Livaditis, 2012; Belli, Ural, & Akbudak, 2012; Coulston, Tanious, Mulder, Porter, & Malhi, 2012; Dolan-Sewell, Krueger, & Shea, 2001; Paris, 2004; Smith, Muir, & Blackwood, 2004; Sripada & Silk, 2007). The most studied question of the bipolar disorder-BPD relationship is the comorbidity between the two disorders. A comprehensive review of two This article was accepted under the editorship of Robert F. Krueger and John Livesley. From the Department of Psychiatry and Human Behavior, Brown Medical School, and the Department of Psychiatry, Rhode Island Hospital, Providence (M. Z., T. A. M., D. Y., I. C. K. D., E. W.). Address correspondence to Mark Zimmerman, MD, 146 West River St., Providence, RI 02904; E-mail: [email protected]
1
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dozen studies of the comorbidity between the two disorders found that approximately 20% of patients with BPD were also diagnosed with bipolar disorder (bipolar I or bipolar II) (Zimmerman & Morgan, 2013). Likewise, approximately 20% of bipolar II patients were diagnosed with BPD, although only 10% of bipolar I patients were diagnosed with BPD. Recently, Perugi and colleagues (2013) examined which BPD criteria were associated with a diagnosis of bipolar disorder in a large sample of depressed patients. They found that unstable relationships, affective instability, impulsivity, and excessive anger significantly predicted a diagnosis of bipolar disorder, whereas chronic emptiness predicted the absence of bipolar disorder. They interpreted their findings as indicating that some BPD criteria are nonspecific and are indicators of bipolar disorder rather than BPD, whereas other criteria are more specific to BPD. This suggests that BPD may present itself differently in patients with bipolar and nonbipolar depression. That is, bipolar patients with BPD are more often characterized by affective instability, anger, and impulsivity, whereas nonbipolar depressed patients with BPD are more often characterized by fears of separation, chronic emptiness, and selfinjurious behavior. In the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, we tested the hypothesis that BPD presents itself differently in psychiatric outpatients diagnosed with bipolar disorder or major depressive disorder.
METHOD The Rhode Island MIDAS project represents an integration of research methodology into a community-based outpatient practice affiliated with an academic medical center (Zimmerman, 2003). A comprehensive diagnostic evaluation is conducted upon presentation for treatment. This private practice group predominantly treats individuals with medical insurance (including Medicare but not Medicaid) on a fee-for-service basis, and it is distinct from the hospital’s outpatient residency training clinic, which predominantly serves lower income, uninsured, and medical assistance patients. Data on referral source were recorded for the last 1,999 patients enrolled in the study. Patients were most frequently referred from primary care physicians (29.7%), psychotherapists (17.4%), and family members or friends (17.7%). The Rhode Island Hospital institutional review committee approved the research protocol, and all patients provided informed, written consent. The sample examined in the present report was derived from the 3,800 psychiatric outpatients evaluated with semistructured diagnostic interviews. Patients were interviewed by a diagnostic rater who administered a modified version of the Structured Clinical Interview for DSM-IV (SCID) (First, Spitzer, Gibbon, & Williams, 1995) and the borderline personality disorder section of the Structured Interview for DSM-IV Personality (SIDP-
jpd169.indd 2
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BPD, BIPOLAR DISORDER, AND MAJOR DEPRESSIVE DISORDER3
IV) (Pfohl, Blum, & Zimmerman, 1997). The present report is based on the 277 patients diagnosed with BPD who were also diagnosed with bipolar depression (n = 46) or major depressive disorder (n = 231). The 277 patients included 74 (26.7%) men and 203 (73.3%) women who ranged in age from 17 to 68 years (mean = 32.97, SD = 9.85). Approximately one quarter of the subjects were married (24.2%, n = 67); the remainder were single (44.4%, n = 123), divorced (16.2%, n = 45), separated 5.1%, n = 14), widowed (0.7%, n = 2), or living with someone as if in a marital relationship (9.4%, n = 26). Approximately two-thirds of the patients attended school beyond high school (62.4%, n = 173), although only one sixth graduated from a 4-year college (15.2%, n = 42). The racial composition of the sample was 85.2% (n = 236) White, 7.2% (n = 20) Black, 4.0% (n = 11) Hispanic, 0.7% (n = 2) Asian, and 2.9% (n = 8) from another or a combination of these racial backgrounds. The diagnostic raters were highly trained and monitored throughout the project to minimize rater drift. The diagnostic raters included PhD-level psychologists and research assistants with college degrees in the social or biological sciences. Research assistants received 3 to 4 months of training during which they observed at least 20 interviews, and they were observed and supervised in their administration of more than 20 evaluations. Psychologists observed only five interviews, and they were observed and supervised in their administration of 15 to 20 evaluations. During the course of training, the senior author met with each rater to review the interpretation of every item on the SCID. In addition, during training every interview was reviewed on an item-by-item basis by the senior rater, who observed the evaluation, and by the senior author, who reviewed the case with the interviewer. At the end of the training period, the raters were required to demonstrate exact, or near exact, agreement with a senior diagnostician on five consecutive evaluations. Throughout the MIDAS project, ongoing supervision of the raters consisted of weekly diagnostic case conferences involving all members of the team. In addition, every case was reviewed by the senior author. Reliability was examined in 65 patients. A joint-interview design was used in which one rater observed another conducting the interview, and both raters independently made their ratings. Of relevance to the present report, the reliabilities for diagnosing MDD (k = 0.90) and bipolar disorder (k = 0.75) were good. The reliability for diagnosing BPD (k = 1.0) was excellent, as was the reliability of the BPD dimension (intraclass correlation coefficient = 0.96).
STATISTICAL ANALYSIS T tests were used to compare the groups on continuously distributed variables. Categorical variables were compared by the chi-square statistic, or by Fisher’s Exact Test if the expected value in any cell of a 2 × 2 table was less than 5.
jpd169.indd 3
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4
ZIMMERMAN ET AL. TABLE 1. Frequency of DSM-IV Borderline Personality Disorder Criteria in Psychiatric Outpatients with Bipolar Disorder or Major Depressive Disorder
DSM-IV Borderline Criteria Abandonment Fear Interpersonal Instability Identity Disturbance Impulsive Behavior Suicidal/Self-Injurious Behavior Affective Instability Chronic Emptiness Excessive Anger Transient Dissociation
Bipolar Disorder (n = 46)
Major Depressive Disorder (n = 231)
%
n
%
n
χ2
p
34.8 73.9 73.9 80.4 54.3 89.1 84.8 82.6 67.4
16 34 34 37 25 41 39 38 31
34.6 77.9 71.4 63.2 52.8 93.1 81.4 84.8 50.6
80 180 165 146 122 215 188 196 117
0.0 0.4 0.1 5.1 0.0 0.9 0.3 0.1 4.3
ns ns ns .02 ns ns ns ns .04
RESULTS The rate of BPD was not significantly different in patients with bipolar I and bipolar II disorder (23.5% vs. 26.1%, χ2 = 0.15, ns), and there was no difference in the mean number of BPD criteria in the two groups (6.7 ± 1.7 vs. 6.2 ± 1.0, t = 1.11, ns). Likewise, there was no difference in the frequency of any of the nine BPD criteria. Consequently, we combined the bipolar I and bipolar II groups and compared the combined group to the patients with MDD. The mean number of criteria was not significantly different in the BPD patients with bipolar disorder and MDD (6.4 ± 1.3 vs. 6.1 ± 1.1, t = –1.52, ns). The patients with bipolar disorder were significantly more likely to report impulsive behavior and transient dissociation (Table 1). No criterion was significantly more common in the BPD patients with MDD. DISCUSSION The present results provide partial support for the hypothesis that BPD presents differently in patients with bipolar versus nonbipolar depression. Consistent with the findings of Perugi et al. (2013), impulsivity was more common in bipolar than nonbipolar depressed patients. However, in contrast to their findings, the bipolar patients more often reported stressrelated dissociative/paranoid reactions, and there was no difference in affective instability, unstable interpersonal relationships, or anger. Some authors have suggested that BPD belongs on the bipolar spectrum because of the high degree of comorbidity between the disorders and the similarity of some phenomenological features, such as affective instability, impulsivity, and irritability (Akiskal, 2004; Belli et al., 2012; Smith et al., 2004; Wilson et al., 2007). While we found greater impulsivity in BPD patients with bipolar disorder, other features that might reflect bipolarity were not more frequent in the bipolar patients. We therefore do not
jpd169.indd 4
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BPD, BIPOLAR DISORDER, AND MAJOR DEPRESSIVE DISORDER5
consider the BPD criteria to be nonspecific with regard to the distinction between BPD and bipolar disorder. The vast majority of patients with BPD have a comorbid mood disorder (Zanarini, Gunderson, & Frankenberg, 1989; Zimmerman & Mattia, 1999). In patients with BPD, it is important to distinguish between MDD and bipolar disorder because this has treatment implications regarding pharmacological management. The present findings suggest that in depressed patients with BPD, the specific criteria met do not provide much guidance in distinguishing between bipolar and nonbipolar disorder. Thus, in patients with MDD, neither the presence of BPD nor the presence of particular BPD features justifies the prescription of mood stabilizer medications because of presumed occult bipolarity. To be sure, mood stabilizers and atypical antipsychotic medications may be beneficial for some features of BPD (Vita, De Peri, & Sacchetti, 2011). However, given the nonspecificity of most psychotropic agents, this does not indicate that the medicationresponsive features of BPD imply a bipolar disorder diathesis. While not the focus of this article, this is the first study to directly compare the frequency of BPD in patients with bipolar I and bipolar II disorder. We found no difference between bipolar I and bipolar II patients in the rate of BPD. This finding is in contrast to recent reviews that found a higher rate of BPD in patients with bipolar II disorder than bipolar I disorder (Paris, Gunderson, & Weinberg, 2007; Zimmerman & Morgan, 2013). In these reviews, the rate of BPD in the diagnostic subtypes was computed across separate studies that focused on patients with only one form of bipolar disorder. Perhaps the discrepancy between our findings and those of the literature reviews was related to the methods of ascertaining the studies’ samples. Our results were derived from a clinical epidemiological sample in which patients were evaluated without regard to their presenting complaint or diagnosis. Thus, we did not select cases that were prototypical patients with bipolar disorder. Studies limited to bipolar I or bipolar II disorder may be more likely to select clear-cut representations of the disorder. More studies are needed with broad inclusion that directly compare patients with bipolar I versus bipolar II disorder to clarify the potential impact of sample selection procedures. In the present study, we followed the Diagnostic and Statistical Manual of Mental Disorders, 4th edition’s (DSM-IV; American Psychological Association, 1994) categorical approach toward diagnosis. To be sure, the distribution of pathology of personality disorders more closely follows a dimensional than a categorical model. Some of the overlap between bipolar disorder and BPD can be partly explained by phenomenological similarities in some of the manifestations of each disorder, the continuous distribution of features of each disorder, and the arbitrariness in the selection of thresholds to denote whether a disorder is present or absent. A limitation of the study is that it was conducted in a single outpatient practice in which the majority of patients were white, female, and had health insurance. Replication of the results in samples with different de-
jpd169.indd 5
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mographic characteristics is warranted. While the generalizability of any single site study is limited, a strength of the study is that the patients were unselected with regard to meeting any inclusion or exclusion criteria. Moreover, a strength of the study is the use of highly trained interviewers who diagnosed BPD and mood disorders with high reliability. We used the DSM-IV criteria to diagnose major depressive disorder and bipolar disorder. The DSM-IV criteria for bipolar disorder have been criticized for being too narrow (Zimmerman, 2012). The overlap between bipolar disorder and the BPD criteria might be greater when a broader definition of bipolar disorder is used (Perugi et al., 2013).
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ect. In M. First (Ed.), Standardized evaluation in clinical practice (Vol. 22, pp. 29–74). Washington, DC: American Psychiatric Publishing, Inc. Zimmerman, M. (2012). Would broadening the diagnostic criteria for bipolar disorder do more harm than good? Implications from longitudinal studies of subthreshold conditions. Journal of Clinical Psychiatry, 73, 437–443. Zimmerman, M., & Mattia, J. I. (1999). Axis I diagnostic comorbidity and borderline personality disorder. Comprehensive Psychiatry, 40, 245–252. Zimmerman, M., & Morgan, T. A. (2013). The relationship between borderline personality disorder and bipolar disorder. Dialogues in Clinical Neuroscience, 15, 79–93.
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