This report is written at a time when, despite the high prevalence of BPD in psychiatric facilities, attention to BPD remains woefully low relative to that paid to other major psychiatric disorders.21
Indeed the diagnosis is underused22,23
and most mental health care professionals avoid or actively dislike patients with BPD.24
This context helps frame the significance of this study. Its results correlate with those of the only other 10-year prospective study of BPD4,5
to demonstrate that BPD psychopathology improves more than generally expected but that psychosocial functioning often remains impaired.
The remission rates found for BPD, very similar to those found in the MSAD,4,25
exceed what might have been predicted from usual clinical assumptions as well as from prior long-term retrospective studies.26–28
Notably, this pattern of remission, occurring in the absence of sustained or BPD-specific treatments,29–31
is consistent with the theory that if patients with BPD can achieve stable supports and avoid interpersonal stressors they will remit clinically.32,33
The relapse data, again mirroring what was found in the MSAD follow-up,4,34
are equally striking. Only 11% of those who remitted subsequently relapsed. The low relapse rate suggests that during the remission process, the patients changed either psychologically, perhaps having acquired more resiliency or new adaptive skills, or situationally by attaining more supports or less stress.
The rates of BPD remission found here resemble those observed in 10-year follow-up studies that used similar follow-up methods for MDD,35
and panic disorders37
but far exceed those for social phobia.37
The rates of BPD relapse found here are dramatically lower than for all of these disorders.35–38
These comparisons underscore the clinically significant and distinct BPD pattern in which BPD remitted significantly more slowly than MDD but only minimally more slowly than OPD and relapsed significantly less often than MDD and OPD. Insofar as 80% of our BPD sample had lifetime MDD,39
the dramatically faster rate to remission of our MDD sample (80% by 1 year) compared with BPD (30% by 1 year) underscores how negatively BPD influences the course of MDD. Similarly, the fact that the rate of relapse found in our MDD sample was lower than in other MDD samples presumably reflects our sample’s lack of personality disorder comorbidity. What is evident appears clinically counterintuitive: patients with BPD improve symptomatically more often, more quickly, and more dramatically than expected and, once better, maintain improvements more enduring than for many other major psychiatric disorders.
The relative stability of BPD criteria reported here extends our prior reports after 2 years of follow-up.9,40
The earlier reports from CLPS, like the 10-year data from the MSAD,25
suggested a hybrid model with more stable criteria being traitlike (eg, affective instability, unstable relationships) and with less stable criteria being more symptomlike or statelike (eg, self-injurious behavior, stress/paranoia). In contrast, these 10-year data failed to confirm this division: all 9 criteria had similar rates and levels (about 50%) of decline with a similar rank ordering of prevalence at all times. Our finding is clinically instructive: criteria that we had previously predicted9,40
would remain intransigently stable traits proved just as likely to diminish over time as those that we expected would prove more episodic and transient. This finding also is notable for failing to show that any of BPD’s 3 major phenotypes, ie, affective, behavioral, or interpersonal, show a distinctive pattern of stability. This perhaps affirms the overriding single-factor unity of the BPD construct.41,42
In any event, the apparent between-study differences are not well understood. They can be partially explained by our use of prevalence rates based on our entire sample in contrast to the MSAD’s use of time-to-remission analyses that apply only to the subjects who had the criteria at baseline, but they may also be related to differences in the samples and the assessment instruments. This issue requires more research.
Despite statistically significant overall improvement in functioning, the magnitude of these improvements was far less dramatic and far less clinically significant than the improvements found on measures of psychopathology. The fact that the patients with BPD improved more than those in the comparison groups reflected their having lower baseline functioning. The initially more severe level of the BPD sample’s functional impairment tended to converge toward the levels of both comparison groups over time. As measured by mean GSA scores at 10 years, BPD’s social adjustment (3.1) lagged considerably below that found for MDD (2.7), bipolar I disorder (2.9), and bipolar II disorder (2.8) after 14 to 15 years.43
As measured by GAF score (ie, mid 50s), our BPD sample was less functional than observed after long-term retrospective follow-up of other BPD samples27,28
(ie, the mid to high 60s) but resembles the MSAD sample.5,44
Why the 2 prospective studies evidenced more dysfunction than the retrospective studies is unclear. Although it could relate to severity of BPD in the samples or to less effective intervening therapies, it seems more likely that the use of rigorous—presumably more valid—assessment methods for diagnosis and functioning established a better estimate.
Our results show that the improvements in the BPD sample’s functioning evident during the first 2 years11
continued to progress, albeit more slowly. The BPD sample’s improvement in specific areas usually moved them from the poor to the satisfactory range of function. Moreover, the analyses of individual change indicate that while average levels of functioning change slowly, subgroups of patients with BPD (and OPD) episodically experienced substantial fluctuations at the individual level; change in function was more the norm than was stability. Thus, with respect to psychosocial function, the traditional pessimism about this disorder’s prognosis seems partially justified. Younger age, consistent with 2 prior reports,45,46
and more education consistently predicted better function, whereas sex had no effect.
Improvement on the employment subscale of the GSA merits a special note insofar as lost productivity accounts for most of the indirect public health care costs for mental illnesses.47
The BPD sample improved from mild or fair (mean score, 2.8) to satisfactory or good (mean score, 2.1). Much of this modest improvement took place in the first 2 years, and the BPD sample’s overall level of employment remained consistently and significantly poorer than for either the OPD or MDD sample. After 10 years, only about one-third had full-time employment—a rate approximating that found in the MSAD for full-time work or school.5
Still, our BPD sample’s mean employment score at 10 years (2.1) appeared somewhat better than that found in prospective 14- to 15-year follow-up of patients with MDD (2.5), bipolar I disorder (2.8), or bipolar II disorder (2.6).43
Of note, while more education did not affect the quantity and quality of overall employment for patients with BPD, it was associated with more likelihood to achieve full-time employment. Also of note, our MDD sample’s level of employment at 10 years (mean score, 2.1) fell inexplicably lower than earlier in the study but remained better than the Collaborative Depression Study sample’s score of 2.5—presumably reflecting their MDD sample’s enrollment from inpatient hospital units and extensive comorbidity with personality disorders, unlike our MDD sample.
The relative severity and persistence of BPD’s social dysfunction and its contrasting levels of improvement in psychopathology echo findings reported in our 2-year follow-up report,11
findings from MSAD,5,48
and the conclusion that McGlashan reached in his earlier study.49
The patterns of improved psychopathology and persisting social dysfunction have been noted for other disorders.43,50,51
However, the finding of a course marked by gradually attained, frequent, and persistent remission is distinctive for BPD. Given that the other prospective 10-year follow-up study4
identified a very similar course, there now exists a strong empirically based prognostic portrait of BPD that can inform clinicians, families, and patients. By virtue of its distinctiveness, this course offers strong validation for the DSM-IV
BPD diagnosis. This validation joins the hard-earned validation of DSM-IV
BPD that has come from descriptive and familiality or heritability research and from disorder-specific therapies.21,52
Because, as reported here, the DSM-IV
definition of BPD—like DSM-IV
definitions of other major psychiatric disorders—identifies a disorder whose course is disjunctive with social disability, it invites the hope that a revised characterization of BPD might more closely correspond to the disorder’s dysfunction and perhaps with its underlying genotype. While current proposals to redefine BPD for DSM-5
and the article by Gunderson53
) might fulfill this hope, they should proceed with due recognition that the existing definition already has difficult-to-attain validation and conveys clinically essential information about course.
That psychopathology would predict dysfunction is consistent with the MSAD findings that symptomatic improvement was associated with better function44
and is also consistent with the idea that sustained periods of active illness can interfere with developmental tasks and leave patients with BPD with “scars” that obstruct satisfactory community-based activities.54
After the first few years, however, the level of psychopathology proved to only weakly predict long-term functional improvement, ie, patients with BPD who failed to remit tended to remain chronically impaired. Although the psychopathology initially reflected in the BPD criteria may be a cause of social disability, if its reduction was slow, it then proved to be only weakly associated with the development of satisfactory and productive lives. Surprisingly, improvement in social function was not significantly associated with subsequent reductions in psychopathology.
An implication of this study is that the enthusiasm generated by the successes reported for psychosocial therapies of patients with BPD55–62
needs to be qualified by the recognition that these treatments have rarely demonstrated that the patients achieve better functional capacities. Clearly, future studies of therapeutic outcome need to assess functional gain, but more importantly, future BPD therapies need to address functional impairment, ie, to incorporate social learning and rehabilitation strategies. The need for rehabilitative strategies has already been recognized with other major mental illnesses.63,64
From a public health viewpoint, it is critical that therapies demonstrate their effectiveness in helping patients with BPD attain and maintain work roles.
The methods and design of this study as well as the confirmatory results from the MSAD permit a much higher level of confidence in our findings than from prior studies. Still, the completion of the study invites reminders of its limitations. The effort to attain a representative clinical urban sample precludes generalization of our findings to nonclinical or rural populations. As with all longitudinal studies, the repeated contacts with research staff may have affected the outcomes. Other limitations include our reliance on the participants as informants (when outside informants may have augmented assessment validity)65
and our reliance on a measure of employment that did not include homemaking. Finally, we are aware of the many related issues that we did not examine, issues such as predictors of change or the isolation of subgroups based on good or poor outcomes, comorbidity, or sex.
In summary, the 10-year outcome of patients with BPD in the CLPS demonstrates a distinctive, clinically useful, and diagnostically validating course characterized by remissions more enduring and by functional impairment more severe than many other major psychiatric disorders. This pattern highlights the potential therapeutic rewards of treating patients with BPD, while challenging the next generation of therapies to help them become more effective by improving functional outcomes. It also highlights the imposing public health issue these patients represent and the embarrassingly disproportionate lack of attention the disorder has received.18