Curr Psychiatry Rep (2013) 15:422 DOI 10.1007/s11920-013-0422-z
BIPOLAR DISORDERS (WH CORYELL, SECTION EDITOR)
Problematic Boundaries in the Diagnosis of Bipolar Disorder: The Interface with Borderline Personality Disorder Mark Zimmerman & Theresa A. Morgan
Published online: 20 November 2013 # Springer Science+Business Media New York 2013
Abstract It is clinically important to recognize both bipolar disorder and borderline personality disorder (BPD) in patients seeking treatment for depression, and it is important to distinguish between the two. The most studied question on the relationship between BPD and bipolar disorder is their diagnostic concordance. Across studies approximately 10 % of patients with BPD had bipolar I disorder and another 10 % had bipolar II disorder. Likewise, approximately 20 % of bipolar II patients were diagnosed with BPD, though only 10 % of bipolar I patients were diagnosed with BPD. While the comorbidity rates are substantial, each disorder is, nonetheless, diagnosed in the absence of the other in the vast majority of cases (80–90 %). In studies examining personality disorders broadly, other personality disorders were more commonly diagnosed in bipolar patients than was BPD. Likewise, the converse is also true: other axis I disorders such as major depression, substance abuse, and post-traumatic stress disorder are more commonly diagnosed in patients with BPD than is bipolar disorder. Studies comparing patients with BPD and bipolar disorder find significant differences on a range of variables. These findings challenge the notion that BPD is part of the bipolar spectrum. While a substantial literature has documented problems with the under-recognition and underdiagnosis of bipolar disorder, more recent studies have found evidence of bipolar disorder over-diagnosis and that BPD is a significant contributor to over-diagnosis. Re-conceptualizing the Diagnostic and Statistical Manual of Mental Disorders, This article is part of the Topical Collection on Bipolar Disorders M. Zimmerman : T. A. Morgan Department of Psychiatry and Human Behavior, Brown Medical School, Providence, RI, USA M. Zimmerman (*) Bayside Medical Center, 235 Plain Street, Providence, RI 02905, USA e-mail: [email protected]
fifth edition, diagnostic criteria for bipolar disorder as a type of test, rather than the final word on diagnosis, shifts the diagnostician from thinking solely whether a patient does or does not have a disorder to considering the risks of falsepositive and false-negative diagnoses, and the ease by which each type of diagnostic error can be corrected by longitudinal observation. Keywords Bipolar disorder . Borderline personality disorder (BPD) . Comorbidity . Bipolar spectrum . Diagnosis . DSM-5 . Psychiatry
Introduction When patients with bipolar disorder present for treatment in the depressive phase of their illness, the diagnosis of bipolar disorder requires eliciting information about a previously experienced manic or hypomanic episode. Because patients’ memory is fallible, or because clinicians may fail to adequately enquire about a history of manic or hypomanic episodes, the under-recognition of bipolar disorder in patients presenting for the treatment of depression has been identified as a significant clinical problem [1–10, 11•] . The diagnosis of bipolar disorder is often delayed, with the time between initial treatment-seeking and the correct diagnosis often taking longer than 10 years [12, 13]. The treatment and clinical implications of the failure to recognize bipolar disorder in depressed patients are significant and include the underprescription of mood-stabilizing medications, an increased risk of rapid cycling, and increased costs of care [4, 14–16]. As a result of the potential morbidity associated with a delay in diagnosis, experts have called for improved recognition of bipolar disorder [1, 6], and screening scales have been developed and recommended to facilitate the identification of bipolar disorder [17–19].
422, Page 2 of 10
The emphasis on improved recognition over the last several years may have resulted in an opposite problem having emerged—bipolar disorder over-diagnosis. Central to the issue of the accurate diagnosis of bipolar disorder is the interface between bipolar disorder and borderline personality disorder (BPD). Some experts have conceptualized BPD as part of the bipolar spectrum and therefore a contributor to the under-recognition of bipolar disorder [20, 21]. However, others have found BPD contributes to the over-diagnosis of bipolar disorder [22•]. In the present article we focus on four aspects of the relationship between these two disorders. First, we examine the most studied question on the relationship between BPD and bipolar disorder—their diagnostic concordance. In reviewing this literature we focus on three questions: (1) What is the frequency of each disorder when the other is present? (2) Is the prevalence of BPD significantly higher in patients with bipolar disorder than in other psychiatric disorders? (3) Is BPD the most common personality disorder in bipolar patients or are other personality disorders more frequent? Second, we review studies that compare patients with bipolar disorder and BPD on demographic and clinical variables. Third, we examine the contribution of BPD to the overdiagnosis of bipolar disorder. And, fourth, we examine the impact of BPD on the performance of screening scales for bipolar disorder.
Frequency of BPD in Patients with Bipolar Disorder Twenty-four studies reported the frequency of BPD in patients with bipolar disorder (Table 1). Most studies were of psychiatric outpatients, and only five were of samples of inpatients (or predominantly inpatients) [23–27]. The majority of the studies assessed BPD when the patients were in remission (n=9) [23, 28–35] or with no more than mild symptom severity (n=6) [24–26, 36–38]; the remainder (n=9) [27, 39–46] assessed BPD when the patient was symptomatic. The Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV (or DSMIII or DSM-III-R) [47] was the most commonly used measure to evaluate axis I and axis II disorders. Most reports focused on either bipolar I or bipolar II disorder, and many did not discuss the bipolar I–bipolar II distinction. Two reports specified the number of patients with bipolar I and bipolar II disorder, but only reported the prevalence of BPD for the entire group without specifying the prevalence of BPD in the bipolar subtypes [29, 48]. Only two groups of investigators examined the frequency of BPD in patients with bipolar I and bipolar II disorder [34, 35, 46]. Across all studies, the frequency of BPD in the 1,255 patients with bipolar disorder was 16.0 % (n=201). In the 12 studies of 598 patients with bipolar I disorder, the prevalence of BPD was 10.7 % (n=64). In the seven studies of 261
Curr Psychiatry Rep (2013) 15:422
patients with bipolar II disorder, the prevalence of BPD was twice as high (22.9 %, n=60). Only two groups of investigators reported data on both bipolar I and bipolar II disorder. In two separate reports, Vieta et al. [34, 35] found that BPD was diagnosed twice as frequently in patients with bipolar II disorder than bipolar I disorder (12.5 % versus 6.2 %). While they did not statistically compare these prevalence rates, we conducted a χ2 test based on the raw data provided in the two articles and found that the difference was not significant (χ2 = 1.71). Similarly, Zimmerman et al. [46] reported a nonsignificantly higher prevalence of BPD in patients with bipolar II disorder. Thus, while the summary across studies suggests a significantly higher rate of BPD in patients with bipolar II than bipolar I disorder, the only two studies that allowed for a direct comparison did not find a significant difference between the two groups. In the seven studies of 389 patients that either did not specify the type of bipolar disorder, or did not present results separately for bipolar I and bipolar II disorder, the rate of BPD was similar to the rate in patients with bipolar II disorder (20.8 %, n=81). Nine studies indicated that they assessed patients upon presentation for treatment or when the patients were depressed [27, 39–42, 44–46, 48]. Eight of these nine studies were of bipolar II disorder or unspecified bipolar disorder. Across these eight studies the prevalence of BPD was 22.5 % (80/ 355), little different than the prevalence for the entire group of patients with bipolar II disorder or unspecified bipolar disorder. This suggests that state effects did not have a robust influence on the prevalence of BPD. Only one study directly examined the effect of psychiatric state on the prevalence of BPD. Peselow et al.[32] interviewed patients upon presentation for treatment of hypomania, and again 8 weeks later— after symptom resolution—and found a non-significant decrease in the prevalence of BPD (23.4 % versus 17.0 %). We are not aware of any comparable studies that interviewed bipolar patients while depressed and again after improvement in depressive symptoms.
Is BPD the Most Frequent Personality Disorder in Patients with Bipolar Disorder? Fifteen studies examined the full-range of personality disorders in patients with bipolar disorder [23–26, 28, 30–37, 39, 44]. BPD was the most frequent diagnosis in only four of the 15 studies [32, 35, 37, 44]. Histrionic personality disorder was the most common diagnosis in four studies [25, 28, 30, 34] and tied for the most common in another two studies [31, 33], and obsessive–compulsive personality disorder was the most common disorder in three studies [23, 26, 36] and tied for the most common in another two studies [31, 33]. Taken together, this suggests that there is no clear evidence that BPD is the most common personality disorder in patients with bipolar
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Table 1 Frequency of borderline personality disorder (BPD) in individuals with bipolar disorder Author [ref.]
Any bipolar disorder
Bipolar I disorder
Bipolar II disorder
Cyclothymia
Sample Size
Sample Size
Sample Size
Sample Size
% (n) with BPD
19
36.8 (7)
% (n) with BPD
% (n) with BPD
Alnaes and Torgersen [39]
19
0.0 (0)
Barbato and Hafner[28] Benazzi [40] Benazzi [41] Brieger et al. [23] Carpenter et al. [36] Carpiniello et al. [29] Comtois et al. [42] Dunayevich et al. [24] Garno et al. [48] Gasperini et al. [30] George et al. [31] Joyce et al. [44] Loftus and Jaeger [37] Perugi et al. [45] Peselow et al. [32] Pica et al. [25] Preston et al. [38] Rossi et al. [26]
42
14.3 (6)
Ucok et al. [33] Vieta et al. [34] Vieta et al. [35] Wilson et al. [27] Zimmerman and Mattia [46]
57 34
31.6 (18) 23.5 (8)
100 54
17.0 (17) 5.5 (3)
26
11.5 (3)
47
71
41
60 23
6.7 (4) 0.0 (0)
56
5.4 (3)
52
3.8 (2)
51
19.6 (10)
% (n) with BPD
50 78
12.0 (6) 11.5 (9)
19
31.6 (6)
25
48.0 (12)
40 30 19
12.5 (5) 50.0 (15) 36.8 (7)
23.4 (11) 26 35
11.5 (3) 40.0 (14)
90 129
10.0 (9) 6.2 (8)
29.6 (21)
34.1 (14)
15
disorder. Nonetheless, it is noteworthy that BPD was the most frequent personality disorder diagnosis in the only two studies of bipolar II disorder [35, 44].
Is BPD More Common in Patients with Bipolar Disorder than Psychiatric Control Groups? Eight studies compared the frequency of BPD in patients with bipolar disorder and major depressive disorder [23, 26, 30, 40, 42, 44, 45, 49]. Four studies found no difference between the two groups [23, 26, 30, 42], whereas three of the four studies of bipolar II disorder found a higher rate of BPD in the bipolar patients [40, 44, 45, 49]. Another study found no difference in the rate of BPD in patients with bipolar disorder and schizophrenia [25]. One study compared the frequency of axis I disorders in a heterogeneous sample of psychiatric outpatients, and sufficient data were provided to calculate the rate of BPD in patients with different diagnoses [46]. BPD was significantly more frequent
33.3 (5)
in patients with bipolar disorder than in patients with major depressive disorder, as well as more common than in patients with any psychiatric disorder. Another study of psychiatric outpatients with mixed diagnoses found a lower rate of BPD in patients with bipolar disorder [39]. Thus, four of ten studies found a significantly higher rate of BPD in patients with bipolar disorder compared to a psychiatric control group, and three of these four positive studies were comparisons of bipolar II disorder versus major depressive disorder.
Frequency of Bipolar Disorder in Patients with BPD Twelve studies reported the frequency of bipolar disorder in patients with BPD (Table 2). Three studies of psychiatric outpatients of mixed diagnoses and one study of patients with a major depressive episode contributed data to both this analysis, as well as the previous analysis examining the frequency of BPD in patients with bipolar disorder [39, 42, 45, 46]. Most
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Curr Psychiatry Rep (2013) 15:422
Table 2 Frequency of bipolar disorder individuals with borderline personality disorder (BPD) Author
n of BPD sample
Akiskal et al. [87] Alnaes and Torgersen [39] Comtois et al. [42] Deltito et al. [88]
100 44 38 16
Hudziak et al. [89] Links et al. [50] a Perugi et al. [45] Pope et al. [90] Prasad et al. [52] Skodol et al. [53] Zanarini et al. [51] Zimmerman and Mattia [46]
87 88 46 33 21 240 379 59
% (n) with any bipolar disorder
21.1 (8) 31.25 (5)
23.8 (5)
% (n) with bipolar I disorder
% (n) with bipolar II disorder
% (n) with cyclothymia
Excluded 0.0 (0)
17.0 (17) b
7.0 (7) 15.9 (7)
12.5 (2)
18.7 (3)
16.1 (14) 5.9 (6) 2.2 (1) 9.1 (3) 16,7 (4) 9.2 (22) Excluded 8.5 (7)
9.6 (8) 26.1 (12)
17.9 (16)
4.8 (1) 6.9 (17) 9.5 (36) 11.9 (7)
a
Links et al. [50] present lifetime and current rates of bipolar disorder; we included lifetime rates.
b
Bipolar II disorder required only a 2-day duration of hypomanic symptoms, and could include pharmacologically-induced hypomanic episodes.
studies were of psychiatric outpatients, and only two were of samples of inpatients [50, 51]. In ten of the 12 studies it was clear that the patients were symptomatic at the time of the evaluation, and in the remaining two studies symptom status was unstated [52, 53]. Half of the studies examined the frequency of both bipolar I and bipolar II disorder. Two studies reported both current and lifetime rates of bipolar disorder, and we included the data on lifetime rates [46, 50]. A difficulty in summarizing the data is that studies varied in the breadth of their diagnosis of bipolar disorder. Only one study reported rates of bipolar I, bipolar II, and cyclothymic disorder [50]. Across all 12 studies, the frequency of any bipolar disorder in the 1,151 patients was 14.1 % (n= 162). The largest study, by Zanarini et al. [51], excluded patients with bipolar I disorder, and the rate of any bipolar disorder in this study was amongst the lowest of the studies summarized in Table 2. When the results of this study are excluded, then the rate of any bipolar disorder across the remaining 11 studies was 16.3 % (126/772). Six studies reported rates of both bipolar I and bipolar II disorder. Across these six studies the rate of either bipolar I or bipolar II disorder was 19.1 % (90/470). In the nine studies of 634 patients that assessed bipolar I disorder, the prevalence was 9.3 % (n=59). In the eight studies assessing bipolar II disorder, the prevalence was 10.1 % (n= 101). Limiting the analysis to the six studies that reported the rates of both bipolar I and bipolar II disorder, the results were the same (bipolar I disorder, 8.9 %; bipolar II disorder, 10.2 %). Only three studies reported the rate of cyclothymic disorder, and across these three studies the overall prevalence was 12.9 % (30/232).
Direct Comparisons of Patients with Bipolar Disorder and BPD with Implications for Including BPD on the Bipolar Spectrum The relatively high frequency of diagnostic co-occurrence and resemblance of phenomenological features has led some authors to suggest that BPD is part of the bipolar spectrum [20, 21]. In fact, in a recent large-scale international study, the presence of BPD was considered a validator of the distinction between bipolar and non-bipolar disorder [11•]. Several review articles have summarized the evidence in support of and opposed to the hypothesis that BPD belongs to the bipolar spectrum [49, 54–56]. One of the noteworthy findings of these reviews is the sparsity of studies that directly compared individuals diagnosed with bipolar disorder and BPD. Moreover, the few studies that have directly compared the two disorders have been based on small samples and examined a limited number of variables. Atre-Vaidya and Hussain [57] compared ten patients with BPD to 13 patients with bipolar disorder on the Temperament Character Inventory and found significant differences on three of seven personality dimensions. Berrocal et al. [58] compared 25 BPD patients without a current or lifetime history of mood disorders, 16 patients with bipolar disorder without BPD, and 19 patients with major depressive disorder (MDD) without BPD on a self-report measure of lifetime mood phenomenology and found no significant differences between BPD and bipolar disorder. Henry et al. [59] compared four groups of patients: BPD without bipolar II disorder (n=29), bipolar II without BPD (n=14), BPD and bipolar II (n=12), and a control group of patients who did not meet criteria for either disorder but had another personality disorder (n=93). They found that both BPD and bipolar II disorder were associated with increased levels of affective
Curr Psychiatry Rep (2013) 15:422
lability, though the specific nature of such lability differed. BPD was associated with greater degrees of impulsiveness and hostility than patients without BPD. Their analysis, however, did not directly compare the BPD and bipolar II groups, but instead was a two-way analysis of variance with the presence or absence of BPD and bipolar II as the main factors; thus, the significant differences were largely owing to differences with patients without either of the two disorders. Likewise, Wilson et al. [27] compared four groups of patients— BPD with MDD (n=72), bipolar II depressed without BPD (n=15), BPD and bipolar II depressed (n=15), and a control group of patients with MDD without BPD (n=71)—on measures of impulsiveness, hostility, and depression symptom severity. Patients with BPD reported significantly higher levels of impulsiveness, hostility, and cognitive and anxious symptoms. The statistical analytic approach was similar to the one used by Henry et al. [59] in that the authors did not directly compare the BPD and bipolar II groups, but instead used a two-way analysis of variance with the presence or absence of BPD and bipolar II as the factors; thus, the significant differences may have been largely owing to differences with the MDD only group. Perry and Cooper [60] compared ten patients with BPD and nine with bipolar II disorder on types of psychodynamic conflicts and found several differences, though no differences were found in the type of defense mechanisms used. Finally, Nilsson et al. [61] compared female outpatients with bipolar I disorder (n=25) and BPD (n= 31) who were in remission from an affective episode, and found that the patients with BPD scored significantly higher on the cyclothymic, depressive, irritable, and anxious temperament subscales of the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire, whereas the patients with bipolar disorder scored higher on the hyperthermic subscale. The patients with BPD also scored higher on 14 of 18 indices of maladaptive self-schemas. While these studies have been limited by small sample sizes and a small number of variables, they have been consistent in finding symptom and personality trait profiles distinguishing BPD from bipolar disorder. Only one study has focused on depressed patients presenting for treatment and compared those who were diagnosed with either bipolar II disorder or BPD. In a report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, our clinical research group compared 206 patients with DSM-IV MDD and BPD (MDD– BPD) and 62 patients with DSM -IV bipolar II depression without BPD on demographic, clinical, and family history variables [62••]. The patients with MDD–BPD were significantly more often diagnosed with post-traumatic disorder, a current substance use disorder, somatoform disorder, and other non-BPDs. Clinical ratings of anger, anxiety, paranoid ideation, and somatization were significantly higher in the MDD–BPD group. The MDD–BPD patients were rated
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significantly lower on the Global Assessment of Functioning, their current social functioning was poorer, and they made significantly more suicide attempts. The patients with bipolar II depression had a significantly higher morbid risk for bipolar disorder in their first-degree relatives than the MDD–BPD patients. Taken together, the findings from these studies, which have examined a variety of clinical variables, support the validity of distinguishing between bipolar disorder and BPD
BPD and the Over-diagnosis of Bipolar Disorder As noted in the introduction, the under-recogntion of bipolar disorder in depressed patients has been a focus of research efforts for several years [1–10]. More recently, some reports have suggested that bipolar disorder is also over-diagnosed at times. For example, Hirschfeld et al. [63] interviewed 180 depressed primary care outpatients receiving antidepressant medication with the Structured Clinical Interview for DSM-IV (SCID). Forty-three patients reported a prior diagnosis of bipolar disorder, and this was not confirmed by the SCID in 32.6 %. Of note, the over-diagnosis rate of 32.6 % was higher than the 21.9 % under-diagnosis rate in the 137 patients who had not been previously diagnosed with bipolar disorder. Stewart and El-Mallakh [64] evaluated 21 patients with a substance use disorder who were admitted for residential treatment and had been previously diagnosed with bipolar disorder. Based on the results of a SCID interview, only nine (42.9 %) were diagnosed with bipolar disorder. The other 12 patients were diagnosed with a substance-induced mood disorder. Goldberg et al. [65] evaluated 85 patients admitted to an inpatient dual diagnosis unit specializing in the treatment of mood and substance use disorders who had been diagnosed with bipolar disorder by their outpatient psychiatrist. Similar to the results of Stewart and El-Mallakh [64], only a minority of the patients (32.9 %) had the diagnosis of bipolar disorder confirmed. None of these studies examined the prevalence of personality disorders using standardized assessment measures. Zimmerman et al. [66] used the SCID to interview 700 psychiatric outpatients presenting for treatment. Prior to the interview the patients completed a self-administered questionnaire which asked them whether they had been previously diagnosed by a healthcare professional with bipolar or manicdepressive disorder. Family history information was obtained from the patients regarding their first-degree relatives. Diagnoses were blind to the results of the self-administered scale. Slightly more than 20 % of the sample reported that they had been previously diagnosed as having bipolar disorder (n=145, 20.7 %), significantly higher than the 12.9 % rate based on the SCID. More than half (56.6 %, n=82) of the 145 patients who reported that they had been previously diagnosed with bipolar
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disorder were not diagnosed with bipolar disorder based on the SCID. Patients with SCID diagnosed bipolar disorder had a significantly higher morbid risk of bipolar disorder than patients who self-reported a previous diagnosis of bipolar disorder that was not confirmed by the SCID. Patients who self-reported a previous diagnosis of bipolar disorder that was not confirmed by the SCID did not have a significantly higher morbid risk for bipolar disorder than the patients who were negative for bipolar disorder by self-report and the SCID. Thus, the results of the study suggested that bipolar disorder is often over-diagnosed, and the family history analyses supported the validity of the diagnostic procedures. A follow-up report examined whether there was a particular diagnostic profile associated with bipolar disorder over-diagnosis [66]. The patients over-diagnosed with bipolar disorder were significantly more likely to be diagnosed with BPD compared to patients who were not diagnosed with bipolar disorder (24.4 % versus 6.1 %, P
BIPOLAR DISORDERS (WH CORYELL, SECTION EDITOR)
Problematic Boundaries in the Diagnosis of Bipolar Disorder: The Interface with Borderline Personality Disorder Mark Zimmerman & Theresa A. Morgan
Published online: 20 November 2013 # Springer Science+Business Media New York 2013
Abstract It is clinically important to recognize both bipolar disorder and borderline personality disorder (BPD) in patients seeking treatment for depression, and it is important to distinguish between the two. The most studied question on the relationship between BPD and bipolar disorder is their diagnostic concordance. Across studies approximately 10 % of patients with BPD had bipolar I disorder and another 10 % had bipolar II disorder. Likewise, approximately 20 % of bipolar II patients were diagnosed with BPD, though only 10 % of bipolar I patients were diagnosed with BPD. While the comorbidity rates are substantial, each disorder is, nonetheless, diagnosed in the absence of the other in the vast majority of cases (80–90 %). In studies examining personality disorders broadly, other personality disorders were more commonly diagnosed in bipolar patients than was BPD. Likewise, the converse is also true: other axis I disorders such as major depression, substance abuse, and post-traumatic stress disorder are more commonly diagnosed in patients with BPD than is bipolar disorder. Studies comparing patients with BPD and bipolar disorder find significant differences on a range of variables. These findings challenge the notion that BPD is part of the bipolar spectrum. While a substantial literature has documented problems with the under-recognition and underdiagnosis of bipolar disorder, more recent studies have found evidence of bipolar disorder over-diagnosis and that BPD is a significant contributor to over-diagnosis. Re-conceptualizing the Diagnostic and Statistical Manual of Mental Disorders, This article is part of the Topical Collection on Bipolar Disorders M. Zimmerman : T. A. Morgan Department of Psychiatry and Human Behavior, Brown Medical School, Providence, RI, USA M. Zimmerman (*) Bayside Medical Center, 235 Plain Street, Providence, RI 02905, USA e-mail: [email protected]
fifth edition, diagnostic criteria for bipolar disorder as a type of test, rather than the final word on diagnosis, shifts the diagnostician from thinking solely whether a patient does or does not have a disorder to considering the risks of falsepositive and false-negative diagnoses, and the ease by which each type of diagnostic error can be corrected by longitudinal observation. Keywords Bipolar disorder . Borderline personality disorder (BPD) . Comorbidity . Bipolar spectrum . Diagnosis . DSM-5 . Psychiatry
Introduction When patients with bipolar disorder present for treatment in the depressive phase of their illness, the diagnosis of bipolar disorder requires eliciting information about a previously experienced manic or hypomanic episode. Because patients’ memory is fallible, or because clinicians may fail to adequately enquire about a history of manic or hypomanic episodes, the under-recognition of bipolar disorder in patients presenting for the treatment of depression has been identified as a significant clinical problem [1–10, 11•] . The diagnosis of bipolar disorder is often delayed, with the time between initial treatment-seeking and the correct diagnosis often taking longer than 10 years [12, 13]. The treatment and clinical implications of the failure to recognize bipolar disorder in depressed patients are significant and include the underprescription of mood-stabilizing medications, an increased risk of rapid cycling, and increased costs of care [4, 14–16]. As a result of the potential morbidity associated with a delay in diagnosis, experts have called for improved recognition of bipolar disorder [1, 6], and screening scales have been developed and recommended to facilitate the identification of bipolar disorder [17–19].
422, Page 2 of 10
The emphasis on improved recognition over the last several years may have resulted in an opposite problem having emerged—bipolar disorder over-diagnosis. Central to the issue of the accurate diagnosis of bipolar disorder is the interface between bipolar disorder and borderline personality disorder (BPD). Some experts have conceptualized BPD as part of the bipolar spectrum and therefore a contributor to the under-recognition of bipolar disorder [20, 21]. However, others have found BPD contributes to the over-diagnosis of bipolar disorder [22•]. In the present article we focus on four aspects of the relationship between these two disorders. First, we examine the most studied question on the relationship between BPD and bipolar disorder—their diagnostic concordance. In reviewing this literature we focus on three questions: (1) What is the frequency of each disorder when the other is present? (2) Is the prevalence of BPD significantly higher in patients with bipolar disorder than in other psychiatric disorders? (3) Is BPD the most common personality disorder in bipolar patients or are other personality disorders more frequent? Second, we review studies that compare patients with bipolar disorder and BPD on demographic and clinical variables. Third, we examine the contribution of BPD to the overdiagnosis of bipolar disorder. And, fourth, we examine the impact of BPD on the performance of screening scales for bipolar disorder.
Frequency of BPD in Patients with Bipolar Disorder Twenty-four studies reported the frequency of BPD in patients with bipolar disorder (Table 1). Most studies were of psychiatric outpatients, and only five were of samples of inpatients (or predominantly inpatients) [23–27]. The majority of the studies assessed BPD when the patients were in remission (n=9) [23, 28–35] or with no more than mild symptom severity (n=6) [24–26, 36–38]; the remainder (n=9) [27, 39–46] assessed BPD when the patient was symptomatic. The Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV (or DSMIII or DSM-III-R) [47] was the most commonly used measure to evaluate axis I and axis II disorders. Most reports focused on either bipolar I or bipolar II disorder, and many did not discuss the bipolar I–bipolar II distinction. Two reports specified the number of patients with bipolar I and bipolar II disorder, but only reported the prevalence of BPD for the entire group without specifying the prevalence of BPD in the bipolar subtypes [29, 48]. Only two groups of investigators examined the frequency of BPD in patients with bipolar I and bipolar II disorder [34, 35, 46]. Across all studies, the frequency of BPD in the 1,255 patients with bipolar disorder was 16.0 % (n=201). In the 12 studies of 598 patients with bipolar I disorder, the prevalence of BPD was 10.7 % (n=64). In the seven studies of 261
Curr Psychiatry Rep (2013) 15:422
patients with bipolar II disorder, the prevalence of BPD was twice as high (22.9 %, n=60). Only two groups of investigators reported data on both bipolar I and bipolar II disorder. In two separate reports, Vieta et al. [34, 35] found that BPD was diagnosed twice as frequently in patients with bipolar II disorder than bipolar I disorder (12.5 % versus 6.2 %). While they did not statistically compare these prevalence rates, we conducted a χ2 test based on the raw data provided in the two articles and found that the difference was not significant (χ2 = 1.71). Similarly, Zimmerman et al. [46] reported a nonsignificantly higher prevalence of BPD in patients with bipolar II disorder. Thus, while the summary across studies suggests a significantly higher rate of BPD in patients with bipolar II than bipolar I disorder, the only two studies that allowed for a direct comparison did not find a significant difference between the two groups. In the seven studies of 389 patients that either did not specify the type of bipolar disorder, or did not present results separately for bipolar I and bipolar II disorder, the rate of BPD was similar to the rate in patients with bipolar II disorder (20.8 %, n=81). Nine studies indicated that they assessed patients upon presentation for treatment or when the patients were depressed [27, 39–42, 44–46, 48]. Eight of these nine studies were of bipolar II disorder or unspecified bipolar disorder. Across these eight studies the prevalence of BPD was 22.5 % (80/ 355), little different than the prevalence for the entire group of patients with bipolar II disorder or unspecified bipolar disorder. This suggests that state effects did not have a robust influence on the prevalence of BPD. Only one study directly examined the effect of psychiatric state on the prevalence of BPD. Peselow et al.[32] interviewed patients upon presentation for treatment of hypomania, and again 8 weeks later— after symptom resolution—and found a non-significant decrease in the prevalence of BPD (23.4 % versus 17.0 %). We are not aware of any comparable studies that interviewed bipolar patients while depressed and again after improvement in depressive symptoms.
Is BPD the Most Frequent Personality Disorder in Patients with Bipolar Disorder? Fifteen studies examined the full-range of personality disorders in patients with bipolar disorder [23–26, 28, 30–37, 39, 44]. BPD was the most frequent diagnosis in only four of the 15 studies [32, 35, 37, 44]. Histrionic personality disorder was the most common diagnosis in four studies [25, 28, 30, 34] and tied for the most common in another two studies [31, 33], and obsessive–compulsive personality disorder was the most common disorder in three studies [23, 26, 36] and tied for the most common in another two studies [31, 33]. Taken together, this suggests that there is no clear evidence that BPD is the most common personality disorder in patients with bipolar
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Table 1 Frequency of borderline personality disorder (BPD) in individuals with bipolar disorder Author [ref.]
Any bipolar disorder
Bipolar I disorder
Bipolar II disorder
Cyclothymia
Sample Size
Sample Size
Sample Size
Sample Size
% (n) with BPD
19
36.8 (7)
% (n) with BPD
% (n) with BPD
Alnaes and Torgersen [39]
19
0.0 (0)
Barbato and Hafner[28] Benazzi [40] Benazzi [41] Brieger et al. [23] Carpenter et al. [36] Carpiniello et al. [29] Comtois et al. [42] Dunayevich et al. [24] Garno et al. [48] Gasperini et al. [30] George et al. [31] Joyce et al. [44] Loftus and Jaeger [37] Perugi et al. [45] Peselow et al. [32] Pica et al. [25] Preston et al. [38] Rossi et al. [26]
42
14.3 (6)
Ucok et al. [33] Vieta et al. [34] Vieta et al. [35] Wilson et al. [27] Zimmerman and Mattia [46]
57 34
31.6 (18) 23.5 (8)
100 54
17.0 (17) 5.5 (3)
26
11.5 (3)
47
71
41
60 23
6.7 (4) 0.0 (0)
56
5.4 (3)
52
3.8 (2)
51
19.6 (10)
% (n) with BPD
50 78
12.0 (6) 11.5 (9)
19
31.6 (6)
25
48.0 (12)
40 30 19
12.5 (5) 50.0 (15) 36.8 (7)
23.4 (11) 26 35
11.5 (3) 40.0 (14)
90 129
10.0 (9) 6.2 (8)
29.6 (21)
34.1 (14)
15
disorder. Nonetheless, it is noteworthy that BPD was the most frequent personality disorder diagnosis in the only two studies of bipolar II disorder [35, 44].
Is BPD More Common in Patients with Bipolar Disorder than Psychiatric Control Groups? Eight studies compared the frequency of BPD in patients with bipolar disorder and major depressive disorder [23, 26, 30, 40, 42, 44, 45, 49]. Four studies found no difference between the two groups [23, 26, 30, 42], whereas three of the four studies of bipolar II disorder found a higher rate of BPD in the bipolar patients [40, 44, 45, 49]. Another study found no difference in the rate of BPD in patients with bipolar disorder and schizophrenia [25]. One study compared the frequency of axis I disorders in a heterogeneous sample of psychiatric outpatients, and sufficient data were provided to calculate the rate of BPD in patients with different diagnoses [46]. BPD was significantly more frequent
33.3 (5)
in patients with bipolar disorder than in patients with major depressive disorder, as well as more common than in patients with any psychiatric disorder. Another study of psychiatric outpatients with mixed diagnoses found a lower rate of BPD in patients with bipolar disorder [39]. Thus, four of ten studies found a significantly higher rate of BPD in patients with bipolar disorder compared to a psychiatric control group, and three of these four positive studies were comparisons of bipolar II disorder versus major depressive disorder.
Frequency of Bipolar Disorder in Patients with BPD Twelve studies reported the frequency of bipolar disorder in patients with BPD (Table 2). Three studies of psychiatric outpatients of mixed diagnoses and one study of patients with a major depressive episode contributed data to both this analysis, as well as the previous analysis examining the frequency of BPD in patients with bipolar disorder [39, 42, 45, 46]. Most
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Table 2 Frequency of bipolar disorder individuals with borderline personality disorder (BPD) Author
n of BPD sample
Akiskal et al. [87] Alnaes and Torgersen [39] Comtois et al. [42] Deltito et al. [88]
100 44 38 16
Hudziak et al. [89] Links et al. [50] a Perugi et al. [45] Pope et al. [90] Prasad et al. [52] Skodol et al. [53] Zanarini et al. [51] Zimmerman and Mattia [46]
87 88 46 33 21 240 379 59
% (n) with any bipolar disorder
21.1 (8) 31.25 (5)
23.8 (5)
% (n) with bipolar I disorder
% (n) with bipolar II disorder
% (n) with cyclothymia
Excluded 0.0 (0)
17.0 (17) b
7.0 (7) 15.9 (7)
12.5 (2)
18.7 (3)
16.1 (14) 5.9 (6) 2.2 (1) 9.1 (3) 16,7 (4) 9.2 (22) Excluded 8.5 (7)
9.6 (8) 26.1 (12)
17.9 (16)
4.8 (1) 6.9 (17) 9.5 (36) 11.9 (7)
a
Links et al. [50] present lifetime and current rates of bipolar disorder; we included lifetime rates.
b
Bipolar II disorder required only a 2-day duration of hypomanic symptoms, and could include pharmacologically-induced hypomanic episodes.
studies were of psychiatric outpatients, and only two were of samples of inpatients [50, 51]. In ten of the 12 studies it was clear that the patients were symptomatic at the time of the evaluation, and in the remaining two studies symptom status was unstated [52, 53]. Half of the studies examined the frequency of both bipolar I and bipolar II disorder. Two studies reported both current and lifetime rates of bipolar disorder, and we included the data on lifetime rates [46, 50]. A difficulty in summarizing the data is that studies varied in the breadth of their diagnosis of bipolar disorder. Only one study reported rates of bipolar I, bipolar II, and cyclothymic disorder [50]. Across all 12 studies, the frequency of any bipolar disorder in the 1,151 patients was 14.1 % (n= 162). The largest study, by Zanarini et al. [51], excluded patients with bipolar I disorder, and the rate of any bipolar disorder in this study was amongst the lowest of the studies summarized in Table 2. When the results of this study are excluded, then the rate of any bipolar disorder across the remaining 11 studies was 16.3 % (126/772). Six studies reported rates of both bipolar I and bipolar II disorder. Across these six studies the rate of either bipolar I or bipolar II disorder was 19.1 % (90/470). In the nine studies of 634 patients that assessed bipolar I disorder, the prevalence was 9.3 % (n=59). In the eight studies assessing bipolar II disorder, the prevalence was 10.1 % (n= 101). Limiting the analysis to the six studies that reported the rates of both bipolar I and bipolar II disorder, the results were the same (bipolar I disorder, 8.9 %; bipolar II disorder, 10.2 %). Only three studies reported the rate of cyclothymic disorder, and across these three studies the overall prevalence was 12.9 % (30/232).
Direct Comparisons of Patients with Bipolar Disorder and BPD with Implications for Including BPD on the Bipolar Spectrum The relatively high frequency of diagnostic co-occurrence and resemblance of phenomenological features has led some authors to suggest that BPD is part of the bipolar spectrum [20, 21]. In fact, in a recent large-scale international study, the presence of BPD was considered a validator of the distinction between bipolar and non-bipolar disorder [11•]. Several review articles have summarized the evidence in support of and opposed to the hypothesis that BPD belongs to the bipolar spectrum [49, 54–56]. One of the noteworthy findings of these reviews is the sparsity of studies that directly compared individuals diagnosed with bipolar disorder and BPD. Moreover, the few studies that have directly compared the two disorders have been based on small samples and examined a limited number of variables. Atre-Vaidya and Hussain [57] compared ten patients with BPD to 13 patients with bipolar disorder on the Temperament Character Inventory and found significant differences on three of seven personality dimensions. Berrocal et al. [58] compared 25 BPD patients without a current or lifetime history of mood disorders, 16 patients with bipolar disorder without BPD, and 19 patients with major depressive disorder (MDD) without BPD on a self-report measure of lifetime mood phenomenology and found no significant differences between BPD and bipolar disorder. Henry et al. [59] compared four groups of patients: BPD without bipolar II disorder (n=29), bipolar II without BPD (n=14), BPD and bipolar II (n=12), and a control group of patients who did not meet criteria for either disorder but had another personality disorder (n=93). They found that both BPD and bipolar II disorder were associated with increased levels of affective
Curr Psychiatry Rep (2013) 15:422
lability, though the specific nature of such lability differed. BPD was associated with greater degrees of impulsiveness and hostility than patients without BPD. Their analysis, however, did not directly compare the BPD and bipolar II groups, but instead was a two-way analysis of variance with the presence or absence of BPD and bipolar II as the main factors; thus, the significant differences were largely owing to differences with patients without either of the two disorders. Likewise, Wilson et al. [27] compared four groups of patients— BPD with MDD (n=72), bipolar II depressed without BPD (n=15), BPD and bipolar II depressed (n=15), and a control group of patients with MDD without BPD (n=71)—on measures of impulsiveness, hostility, and depression symptom severity. Patients with BPD reported significantly higher levels of impulsiveness, hostility, and cognitive and anxious symptoms. The statistical analytic approach was similar to the one used by Henry et al. [59] in that the authors did not directly compare the BPD and bipolar II groups, but instead used a two-way analysis of variance with the presence or absence of BPD and bipolar II as the factors; thus, the significant differences may have been largely owing to differences with the MDD only group. Perry and Cooper [60] compared ten patients with BPD and nine with bipolar II disorder on types of psychodynamic conflicts and found several differences, though no differences were found in the type of defense mechanisms used. Finally, Nilsson et al. [61] compared female outpatients with bipolar I disorder (n=25) and BPD (n= 31) who were in remission from an affective episode, and found that the patients with BPD scored significantly higher on the cyclothymic, depressive, irritable, and anxious temperament subscales of the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire, whereas the patients with bipolar disorder scored higher on the hyperthermic subscale. The patients with BPD also scored higher on 14 of 18 indices of maladaptive self-schemas. While these studies have been limited by small sample sizes and a small number of variables, they have been consistent in finding symptom and personality trait profiles distinguishing BPD from bipolar disorder. Only one study has focused on depressed patients presenting for treatment and compared those who were diagnosed with either bipolar II disorder or BPD. In a report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, our clinical research group compared 206 patients with DSM-IV MDD and BPD (MDD– BPD) and 62 patients with DSM -IV bipolar II depression without BPD on demographic, clinical, and family history variables [62••]. The patients with MDD–BPD were significantly more often diagnosed with post-traumatic disorder, a current substance use disorder, somatoform disorder, and other non-BPDs. Clinical ratings of anger, anxiety, paranoid ideation, and somatization were significantly higher in the MDD–BPD group. The MDD–BPD patients were rated
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significantly lower on the Global Assessment of Functioning, their current social functioning was poorer, and they made significantly more suicide attempts. The patients with bipolar II depression had a significantly higher morbid risk for bipolar disorder in their first-degree relatives than the MDD–BPD patients. Taken together, the findings from these studies, which have examined a variety of clinical variables, support the validity of distinguishing between bipolar disorder and BPD
BPD and the Over-diagnosis of Bipolar Disorder As noted in the introduction, the under-recogntion of bipolar disorder in depressed patients has been a focus of research efforts for several years [1–10]. More recently, some reports have suggested that bipolar disorder is also over-diagnosed at times. For example, Hirschfeld et al. [63] interviewed 180 depressed primary care outpatients receiving antidepressant medication with the Structured Clinical Interview for DSM-IV (SCID). Forty-three patients reported a prior diagnosis of bipolar disorder, and this was not confirmed by the SCID in 32.6 %. Of note, the over-diagnosis rate of 32.6 % was higher than the 21.9 % under-diagnosis rate in the 137 patients who had not been previously diagnosed with bipolar disorder. Stewart and El-Mallakh [64] evaluated 21 patients with a substance use disorder who were admitted for residential treatment and had been previously diagnosed with bipolar disorder. Based on the results of a SCID interview, only nine (42.9 %) were diagnosed with bipolar disorder. The other 12 patients were diagnosed with a substance-induced mood disorder. Goldberg et al. [65] evaluated 85 patients admitted to an inpatient dual diagnosis unit specializing in the treatment of mood and substance use disorders who had been diagnosed with bipolar disorder by their outpatient psychiatrist. Similar to the results of Stewart and El-Mallakh [64], only a minority of the patients (32.9 %) had the diagnosis of bipolar disorder confirmed. None of these studies examined the prevalence of personality disorders using standardized assessment measures. Zimmerman et al. [66] used the SCID to interview 700 psychiatric outpatients presenting for treatment. Prior to the interview the patients completed a self-administered questionnaire which asked them whether they had been previously diagnosed by a healthcare professional with bipolar or manicdepressive disorder. Family history information was obtained from the patients regarding their first-degree relatives. Diagnoses were blind to the results of the self-administered scale. Slightly more than 20 % of the sample reported that they had been previously diagnosed as having bipolar disorder (n=145, 20.7 %), significantly higher than the 12.9 % rate based on the SCID. More than half (56.6 %, n=82) of the 145 patients who reported that they had been previously diagnosed with bipolar
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disorder were not diagnosed with bipolar disorder based on the SCID. Patients with SCID diagnosed bipolar disorder had a significantly higher morbid risk of bipolar disorder than patients who self-reported a previous diagnosis of bipolar disorder that was not confirmed by the SCID. Patients who self-reported a previous diagnosis of bipolar disorder that was not confirmed by the SCID did not have a significantly higher morbid risk for bipolar disorder than the patients who were negative for bipolar disorder by self-report and the SCID. Thus, the results of the study suggested that bipolar disorder is often over-diagnosed, and the family history analyses supported the validity of the diagnostic procedures. A follow-up report examined whether there was a particular diagnostic profile associated with bipolar disorder over-diagnosis [66]. The patients over-diagnosed with bipolar disorder were significantly more likely to be diagnosed with BPD compared to patients who were not diagnosed with bipolar disorder (24.4 % versus 6.1 %, P
