Nightmare disorder, dream anxiety, and subjective sleep quality in patients with borderline personality disorder

Authors


Umit B. Semiz, MD, GATA Haydarpasa Egitim Hastanesi, Psikiyatri Servisi, Uskudar, 34668 Istanbul, Turkey. Email: semizub@yahoo.com

Abstract

Aims:  The aims of the present study were to examine the rate of nightmare disorder (ND) and to determine the levels of dream anxiety and subjective sleep quality in patients with borderline personality disorder (BPD). Another aim was to determine whether dream anxiety was associated with childhood trauma, dissociative experiences, and subjective sleep disturbance in BPD patients. Finally, the hypothesis as to whether BPD patients with ND exhibited a more severe clinical profile than those without ND, was also tested.

Methods:  A total of 88 borderline patients and 100 age- and sex-matched healthy control subjects were assessed using the Structured Clinical Interview for DSM-III-R Personality Disorders, Structured Clinical Interview for DSM-IV Axis I Disorders, Van Dream Anxiety Scale, Pittsburgh Sleep Quality Index, Dissociative Experiences Scale, and Traumatic Experiences Checklist. Subjects with codiagnoses that could affect sleep were not included.

Results:  BPD patients suffered a significantly greater rate of nightmares, elevated levels of dream anxiety, and disturbed sleep quality than did controls. In the borderline group, heightened dream anxiety was correlated with higher rates of early traumatic experiences and dissociative symptoms, and impaired sleep quality. Furthermore, borderline patients with ND exhibited greater psychopathology as compared to those without ND in terms of several clinical characteristics.

Conclusions:  The present study provides support for a strong association between BPD, distressing nightmares, and subjective sleep quality. Recognition and management of dream and sleep disturbances in BPD patients might lead to improvements in their global clinical picture.

PATIENTS DIAGNOSED WITH borderline personality disorder (BPD) usually meet criteria for other comorbid psychiatric conditions. One important but underrepresented commonality among these psychiatric conditions is sleep and dream disturbances. Nightmares and sleep problems are frequently encountered in patients with BPD.1,2 Empirical data suggest that borderline patients are different from normal controls in some aspects of sleep architecture: they have reduced REM latency, less total sleep, more stage 1 sleep, and less stage 4 sleep.3

Although childhood trauma is commonly encountered in BPD4 and often presumed to be associated with sleep disruption and nightmares, it was not explored as a possible confounding factor in most studies. Adults as well as children with a history of early trauma frequently report persistent disruptions in sleep that may be relatively refractory to treatment.5,6 Research on adult sexual assault survivors has shown that upward of 77% of survivors report insomnia, nightmares, sleep-disordered breathing, and/or sleep-related movement disorders and that suffering from sleep problems likely persists for manyyears after the initial trauma.7 Dissociative experiences have also been strongly linked to the childhood traumatization and BPD pathology.8 In a large group of adolescents, Agargun et al. recently demonstrated an association between dream anxiety, nightmares and dissociative states and the causal role of childhood traumatic events in this relationship.9

Despite the growing concern about both sleep and nightmare research, patients with BPD are rarely evaluated with validated sleep scales to assess nightmares and sleep disturbances as primary variables of interest. To our knowledge, an investigation of nightmare disorder (ND) along with subjective measure of dream anxiety and sleep quality in BPD patients has yet to be reported. Previous polysomnographic studies in BPD usually did not provide data on questionnaires validated to indicate the presence of sleep disturbances. Although the gold standard measure of sleep is polysomnography, it also has several disadvantages, such as expensiveness, first-night effect, and need of skilled technical staff. Subjective reports on sleep quantity and quality are also important measures. Several questionnaires, filled out immediately on waking, have been validated to index the presence of sleep disturbance and to be highly correlated with objective estimates of sleep.10 Besides poor sleep quality, a significant proportion of nightmare sufferers also report waking distress and dream anxiety in relation to their nightmares.11 It has been suggested that nightmare distress may itself be, at least partially, a trait factor.11 As such, dream anxiety might be more a function of personality than of nightmare content, and nightmare frequency more a function of acute stress.12 Therefore, it seems reasonable also to measure the dream anxiety when conducting a nightmare study in subjects with a particular personality disorder.

The aim of the present study was to determine the rate of ND and subjective ratings of dream anxiety and sleep disturbances among patients with BPD in comparison to healthy controls. Another aim was to assess whether the level of dream anxiety was associated with measures of childhood traumatic experiences, dissociative symptoms, and subjective sleep complaints in BPD patients. Finally, the present study also examined the hypothesis that the presence of comorbid ND diagnosis would be related to a more severe clinical profile in BPD patients.

METHODS

Subjects

Of 163 BPD patients, who were consecutively admitted to Personality Disorders Research Program at GATA Haydarpasa Training Hospital Psychiatric Clinic during a 24-month study period, 112 were willing and suitable to participate in the study. However, 14 patients refused to participate during data gathering and another 10 left the study because of insufficient hospital stay to administer all instruments. Thus, a total of 88 (48 male, 40 female) borderline subjects were involved in the trial. Diagnosis of BPD was confirmed on the Turkish version of the Structured Clinical Interview for DSM-III-R Personality Disorders13 and subjects with other Axis II codiagnoses were not included. In addition, all subjects were assessed using Structured Clinical Interview for DSM-IV Axis I Disorders.14 Because nightmares may also be related to recent events and present mental status, subjects who had been diagnosed with any psychotic or mood disorder, acute and post-traumatic stress disorder, or an organic condition that could cause psychiatric symptoms and who had experienced a similar event during the past 1 year were excluded.

BPD patients were compared with a healthy control group that included 100 age- and gender-matched subjects. All patients and control subjects were free of any substance or psychotropic medication for at least 4 weeks prior to investigation. Protocol for this research project was approved by the local ethics committee. Written informed consent was obtained from BPD and healthy subjects prior to study participation.

Instruments

The subjects were interviewed with a semi-structured interview for sociodemographic characteristics. The interview also contained a clinician-rated questionnaire to assess the diagnosis and some clinical characteristics of ND according to the DSM-IV criteria. All subjects were informed of the difference between nightmares and night terrors, and were given a brief description of what to consider as a nightmare. This procedure was similar to two recent studies.9,15

The Van Dream Anxiety Scale (VDAS) provides a longitudinal assessment of dream anxiety and treatment response in subjects with nightmares.16 It has a good level of internal consistency (Cronbach's α = 0.87). There are 17 self-rated questions in the scale. Thirteen questions are concerned with nightmare frequency; difficulty in falling asleep; fear of sleeping; trouble sleeping; autonomic hyperactivity; dream recall frequency; daytime sleepiness; daytime anxiety; occupational distress; familial distress; social distress; psychological problems; and memory/concentration problems. The items are weighted equally on a 0–4 scale and summed to yield a global VDAS score, which has a range of 0–42.

The Pittsburgh Sleep Quality Index (PSQI) is a self-rated questionnaire that assesses sleep quality and disturbances over a 1-month interval.17 Nineteen individual items weighted equally on a 0–3 scale generate seven component scores: subjective sleep quality; sleep latency; sleep duration; habitual sleep efficiency; sleep disturbances; use of sleeping medications; and daytime dysfunction. The sum of scores for these seven components yields one global score, which has a range of 0–21, with higher scores indicating worse sleep quality. A global PSQI score >5 is considered to be a sensitive and specific measure of poor sleep quality. The PSQI has been shown to be valid and reliable in Turkish population studies.18

To assess childhood trauma history, the Traumatic Experiences Checklist (TEC) was used. The TEC is a self-report questionnaire covering 29 types of potentially traumatizing events with good psychometric characteristics in clinical samples.19 TEC total score presents the number of reported potentially traumatizing experiences (range 0–29). A previous study demonstrated that the scalability, reliability, and validity of the Turkish version of this instrument were satisfactory.20

The Dissociative Experiences Scale (DES) is a 28-item self-report scale that requires the individual to indicate on a scale ranging from 0 to 100 to what extent presented statements of dissociative experiences apply to them.21 The statements include experiences such as having done something without knowing when and how or finding oneself at a place without being able to recollect how one got there. The overall DES score is obtained by adding up the 28 item scores and dividing by 28; this yields an overall score ranging from 0 to 100. The Turkish version of the scale22 has a reliability and validity as high as its original form.

Statistical analysis

Clinical data were expressed as percentages or means ± SD. Differences between variables were tested for significance using χ2 test or two-tailed t-test when appropriate. Bivariate Pearson's correlations were used to determine the relationships between the scale scores. Statistical significance was set at 0.05 (two-tailed test). All analyses were carried out using SPSS for Windows version 10.0 (SPSS, Chicago, IL, USA).

RESULTS

Table 1 shows the sociodemographic factors of both BPD and healthy control groups. Among BPD subjects, a few more men (n = 48, 54.5%) than women (n = 40, 45.5%) participated in the study. Subjects were relatively young; they ranged in age from 18 to 34 years. Groups were similar with respect to gender, age, marital status, education levels, and economic status. The two groups differed concerning occupational status; more than one-third (36.4%) of BPD patients were unemployed. A diagnosis of ND was found in nearly half (n = 43, 49%) of the BPD subjects while only seven subjects (7%) in the control group were diagnosed as ND.

Table 1.  Subject characteristics and frequency of ND
Sample characteristicsBPD (n = 88)
n (%)
Control (n = 100)
n (%)
Test statistic
  • ***

    P < 0.001.

  • t-test;

  • χ2 test.

  • BPD, borderline personality disorder; ND, nightmare disorder; NS, not significant.

Gender
 Male48 (54.5)57 (57)NS
 Female40 (45.5)43 (43) 
Age (years ± SD)21.7 ± 3.622.3 ± 3.9NS
Marital status
 Never married65 (74)68 (68)NS
 Married14 (16)26 (26) 
 Divorced9 (10)6 (6) 
Education (years ± SD)9.3 ± 3.29.4 ± 3.4NS
Economic status
 Poor19 (21.6)14 (14)NS
 Fair48 (54.5)71 (71) 
 Good21 (23.9)15 (15) 
Occupational status
 Employed56 (63.6)94 (94)26.8***
 Unemployed32 (36.4)6 (6) 
Diagnosis of ND43 (49)7 (7)42.0***

Table 2 shows that the BPD patients displayed significantly higher VDAS global and components scores and PSQI global and item scores than the controls. Eighty-four out of the 88 BPD patients (95.5%) reported themselves to be poor sleepers, that is, to have a PSQI >5. In the control group only 12 subjects (12%) were determined as poor sleepers. The individualized analysis of the different items scored in the PSQI indicated that patients with BPD have higher scores of subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction as compared to the matched controls.

Table 2.  VDAS and PSQI scores
MeasuresBPD (n = 88)Control (n = 100)t (186)
  1. All t are significant at P < 0.001.

  2. BPD, borderline personality disorder; PSQI, Pittsburgh Sleep Quality Index; VDAS, Van Dream Anxiety Scale.

VDAS
 Global VDAS score26.3 ± 10.16.9 ± 5.316.1
 Nightmare frequency3.2 ± 1.21.8 ± 0.59.9
 Difficulty in falling asleep after a nightmare3.3 ± 1.21.7 ± 0.810.8
 Fear of sleeping because of anticipated nightmare2.9 ± 1.61.4 ± 0.78.1
 Trouble sleeping3.1 ± 1.61.3 ± 0.69.7
 Autonomic hyperactivity2.2 ± 1.01.2 ± 0.48.6
 Dream recall frequency2.6 ± 0.91.8 ± 0.86.4
 Daytime sleepiness2.8 ± 1.11.7 ± 1.07.1
 Daytime anxiety3.8 ± 1.21.7 ± 0.714.5
 Occupational distress3.3 ± 1.31.4 ± 0.811.8
 Familial distress2.6 ± 1.41.4 ± 0.77.5
 Social distress2.6 ± 1.31.2 ± 0.59.4
 Psychological problems3.6 ± 1.31.5 ± 0.513.7
 Memory/concentration problems3.2 ± 1.31.5 ± 0.710.9
PSQI
 PSQI global severity score12.6 ± 3.82.4 ± 2.122.2
 Subjective sleep quality2.0 ± 0.70.5 ± 0.615.7
 Sleep latency2.2 ± 0.80.9 ± 0.712.2
 Sleep duration1.3 ± 0.90.3 ± 0.59.0
 Habitual sleep efficiency1.4 ± 1.20.2 ± 0.58.5
 Sleep disturbances2.1 ± 0.50.4 ± 0.523.3
 Use of sleeping medication1.4 ± 1.40.0 ± 0.09.8
 Daytime dysfunction2.1 ± 0.90.2 ± 0.516.3

Table 3 presents Pearson's correlation coefficients, which determine the relationships between scores on the VDAS and the severity of traumatic experiences on the TEC, dissociative symptoms on the DES, and sleep troubles on the PSQI in BPD group. When controlled for VDAS global score, significant and positive correlations were found for traumatic events, dissociative experiences, and subjective sleep complaints. In particular, most of the item scores of VDAS were also positively correlated with the TEC, DES, and global PSQI scores.

Table 3.  Pearson's correlation coefficients
VDAS scoreTEC scoreDES scorePSQI score
  • *

    P < 0.05,

  • **

    P < 0.01,

  • ***

    P < 0.001.

  • BPD, borderline personality disorder; DES, Dissociative Experiences Scale; NS, not significant; PSQI, Pittsburgh Sleep Quality Index; TEC, Traumatic Experiences Checklist; VDAS, Van Dream Anxiety Scale.

Global VDAS score0.517***0.576***0.662***
Nightmare frequency0.350***0.426***0.679***
Difficulty in falling asleep after a nightmare0.298**0.383***0.623***
Fear of sleeping because of anticipated nightmareNS0.346***0.592***
Trouble sleeping0.448***0.510***0.589***
Autonomic hyperactivity0.381***0.266*0.639***
Dream recall frequencyNSNS0.297**
Daytime sleepinessNSNS0.604***
Daytime anxiety0.221*NS0.715***
Occupational distressNSNS0.556***
Familial distress0.550***0.548***0.687***
Social distress0.391***0.489***0.598***
Psychological problems0.421***0.404***0.653***
Memory/concentration problems0.337***0.325**0.631***

As shown in Table 4, the patients with BPD and comorbid ND presented a clinically more severe profile than those without comorbid ND. Patients with BPD and comorbid ND were more likely to be unemployed and to have achieved a lower level degree than borderline patients without ND. They also suffered a significantly grater rate of childhood sexual abuse, physical abuse, and neglect. With respect to deliberate self-injury, BPD patients with ND reported significantly more various methods and longer duration of self-mutilating behavior than those without ND, although presence of any self-mutilating act did not differ between these groups. Furthermore, borderline patients with ND had a significantly greater rate of substance abuse and repeated suicide attempts, more severe general traumatic experiences, and dissociative symptoms than those without ND.

Table 4.  Clinical measures of BPD subjects
MeasuresBPD with ND (n = 43)
n (%)
BPD without ND (n = 45)
n (%)
Test statistic
  • *

    P < 0.05,

  • **

    P < 0.01,

  • ***

    P < 0.001.

  • t-test;

  • χ2 test.

  • BPD, borderline personality disorder; ND, nightmare disorder; NS, not significant.

Education (years) (mean ± SD)10.9 ± 2.77.7 ± 3.05.2***
Occupation (unemployed)22 (51.2)10 (22.2)7.9**
Childhood sexual abuse14 (32.6)5 (11.1)5.9*
Childhood physical abuse23 (53.5)8 (17.8)12.3***
Childhood neglect24 (55.8)13 (28.9)6.5*
Substance abuse26 (60.5)13 (28.9)8.9**
Repeated suicide attempts38 (88.4)28 (62.2)8.0**
Any self-mutilating act40 (93.0)42 (93.3)NS
Number of self-mutilation methods (>1 method)31 (77.5)15 (35.7)14.5***
Duration of self-mutilation (>1 year)31 (77.5)18 (42.9)10.2**
Traumatic Experience Checklist (mean ± SD)5.1 ± 1.83.3 ± 1.05.7***
Dissociative Experiences Scale (mean ± SD)53.4 ± 15.829.8 ± 7.58.9***

DISCUSSION

The principal aim was to investigate the rate of ND and to determine the extent of self-reported dream anxiety and sleep complaints among BPD patients. This is the first study, to our knowledge, in which the VDAS and PSQI have been used in patients with BPD. The present result indicate that BPD patients suffered a significantly greater rate of nightmares (49%), higher levels of dream anxiety, and more disturbed sleep than did normal individuals. Importantly we found that 95.5% of the BPD subjects endorsed sleep difficulties.

The present results corroborate previous studies of trauma-related sleep disturbances that depend on subjective evaluations and involve numerous reports of sleep difficulties.5,23 Poor sleep among the present borderline subjects was evidenced by lower subjective sleep quality, longer sleep latency, shorter sleep duration, lower habitual sleep efficiency, more sleep disturbances, higher use of sleeping medication, and a higher daytime dysfunction as measured on the PSQI. In a previous study both systematic inquiry and objective assessment with polysomnography did show that patients with BPD slept poorly in comparison to healthy controls.2 However, it has also been suggested that sleep quality is an inherently subjective measure and could be related to factors not measurable on polysomnography.24 In addition, PSQI scores reflect sleep quality over the past month, while polysomnography looks only at the particular night/s studied. A recent sleep study found a strong discrepancy between objective and subjective sleep measurements with regard to sleep quality in non-depressed BPD patients.25 Subjective ratings (including also the PSQI) indicated impaired sleep quality while electrophysiologic sleep parameters only indicated tendencies for depression-like REM sleep abnormalities. Taken together, one may conclude that the sleep quality of patients suffering from BPD is significantly decreased as indicating dissatisfaction with sleep. The reason for this reduction in sleep quality could be found in the altered perception of sleep in BPD.

The high prevalence of ND and sleep difficulties in patients with BPD in the present study adds to the suspicion that they are more common than realized in this patient group. One can speculate that ND, sleep disturbances, and BPD may share a common diathesis. Pharmacological enhancement of serotonin activity with selective serotonin re-uptake inhibitors results in a clinical benefit for both behavioral BPD symptoms26 and trauma-related sleep complaints.27 Thus, altered serotonergic neurotransmission might be a possible and common explanation for sleep disturbances and nightmares in BPD.

The present findings also showed that higher dream anxiety was significantly correlated with higher rates of childhood trauma history, higher levels of dissociation, and poorer sleep quality. Several lines of evidence also suggest that there is a triad of relationships between borderline personality structure, early adverse life events, and susceptibility to nightmares. In the study by Claridge et al. highly borderline subjects were found to report more childhood trauma and distressing nightmares.28 Consistent with the present results, nightmare distress in that study was best predicted by a combination of borderline personality and childhood victimization of sexual abuse and neglect. It has also been suggested that dreams may be necessary to emotional adaptation in childhood traumatic events, and it is possible that nightmares have an adaptive function in this process.9

Supporting the present finding of a correlation between dream anxiety and dissociative symptoms, dreams have been considered as a possible dissociative phenomenon that reflect a monitoring of and reaction to internal and external conditions within the dreamer.29 Moreover, neuroanatomic correlates of underlying mechanisms of nightmares and dissociative phenomena in traumatic events have been suggested to be similar to traumatic dreams, particularly amigdala and fronto-orbital structures.9 There is also a well-established connection between BPD and dissociative disorders. In a recent study reporting a high prevalence of ND among patients with dissociative disorders, ND has been found to be associated with BPD codiagnosis.30

In the present study BPD patients with ND displayed a more severe clinical picture than those without ND in terms of several clinical features. The present results emphasize the importance of nightmare comorbidity as a factor contributing to the level of psychopathology associated with BPD. It is suggested that the number of nightmares that produce high levels of distress may function as an indicator of pathological risk/severity.31 Nightmare sufferers have been shown to constitute a particular high-risk group for psychosis-proneness.32 In relation to major depression, nightmares have been demonstrated to be strongly associated with suicidal behavior.15 Thus, the prognostic significance of ND should not be neglected in the diagnosis of BPD. One may speculate that having nightmares is a poor prognostic factor in this patient population.

Limitations of the present study include exclusion of all borderline patients with one or more coexisting axis I disorders, the possibility of recall bias from use of questionnaires, and the fact that we did not use polysomnography to quantify sleep parameters. Less rigorous exclusion of comorbid axis I disorders and inclusion of them as a covariate in the statistical analysis, and objective assessment using actigraphy or polysomnography might yield different findings.

CONCLUSIONS

The present study extends previous research and provides further support for an association between BPD, distressing nightmares, and poor sleep quality. ND is robustly related to a more severe clinical profile in BPD patients. Furthermore, the present study identifies dream anxiety as a clinical correlate of childhood trauma, current dissociative symptoms, and subjective sleep quality in patients with BPD. Effective strategies to improve sleep in this patient group might lead to vast improvements in their clinical picture.

Ancillary