Somatization as a predictor of suicidal ideation in dissociative disorders

Authors


*Vedat Sar, MD, Clinical Psychotherapy Unit and Dissociative Disorders Program, Department of Psychiatry, Medical Faculty of Istanbul, University of Istanbul, Istanbul Tip Fakültesi Psikiyatri Klinigi 34390 Capa, Istanbul, Turkey. Email: vsar@istanbul.edu.tr

Abstract

Aim:  This study was concerned with correlates of suicidal ideation among patients with chronic complex dissociative disorders.

Method:  Participants were 40 patients diagnosed as having either dissociative identity disorder or dissociative disorder not otherwise specified according to the DSM-IV. The Dissociative Disorders Interview Schedule, the Dissociative Experiences Scale, the Somatoform Dissociation and the Childhood Trauma Questionnaires, the Spielberger Trait Anger Inventory, the Beck Suicidal Ideation Scale, and the Borderline Personality Disorder section of the Structured Clinical Interview for DSM-IV Personality Disorders were administered to all patients.

Results:  Patients with suicidal ideas (n = 15) had concurrent somatization disorder more frequently than the remaining patients. Having significantly high scores on both trait and state dissociation measures, their dissociative disorder was more severe than that of the patients with no suicidal ideation. They had elevated scores for childhood emotional abuse, physical abuse and emotional neglect. Concurrent somatization disorder diagnosis was the only predictor of suicidal ideation when childhood trauma scores and borderline personality disorder diagnosis were controlled.

Conclusions:  Among dissociative patients, there is an association between somatization and suicidal ideation. A trauma-related insecure attachment pattern is considered as a common basis of this symptom cluster.

A HISTORY OF attempted suicide is frequent among patients with dissociative disorders1 and they may present to psychiatric treatment facilities with current suicidal ideas as well.2 Although the rate of completed suicide is relatively low,3 that is, between 1.0% and 2.1%, it remains as a possibility in a subgroup of patients for a prolonged period until stabilization is achieved by effective treatment.4,5 Consequently, patients with a dissociative disorder constitute a principal group in emergency psychiatric wards due to intermittent crisis episodes.2 Nevertheless, suicidal ideation may continue beyond transient crisis situations in dissociative patients, thus, careful suicide assessment is required also throughout long-term management.6 A subgroup of dissociative patients have chronic suicidal ideation that remains extremely resistant to standard psychiatric treatment measures.

Sar et al. found in a large non-clinical sample of Turkish women that presence of a dissociative disorder was highly correlated with self-reported history of suicide attempt.7 Karadag et al. found the same relationship in a population of Turkish chemically dependent inpatients.8 Foote et al. compared outpatients with and without a dissociative disorder diagnosis in a US sample and documented the association of suicidal behavior with dissociative disorder.1 Despite its obvious relevance for general psychiatric management, little is known about predictors of suicidal ideation in dissociative disorders.

The aim of the present study was to evaluate possible correlates of suicidal ideation in a group of patients with chronic complex dissociative disorders; that is, dissociative identity disorder or dissociative disorder not otherwise specified, according to the DSM-IV.9 We did not include patients who had solely depersonalization disorder, dissociative amnesia or fugue. Participants had these syndromes, however, in the context of their complex dissociative disorder, which served as a supraordinate diagnostic category encompassing all dissociative phenomena.

METHODS

Participants

All patients admitted to the Dissociative Disorders Program of the Istanbul University Medical Faculty Hospital in Istanbul, Turkey, over a 3-month period (1 March–31 May 2006) were considered for participation in the study. All patients had a diagnosis of dissociative disorder according to the DSM-IV. Forty patients participated in the study. They were between 16 and 40 years of age; the average age of the probands was 25.8 ± 6.2 years. The male subjects (n = 9, mean age 26.2 ± 4.3 years) were older than the female subjects (n = 31, mean age, 25.6 ± 6.7 years), but the difference was not significant (z = −0.70, d.f. = 39, P = 0.485). Two patients were below 18 years of age. The patients had a mean of 11.0 ± 3.1 years of education (range, 5–17 years). The patients who agreed to participate provided written informed consent after the study procedures had been fully explained. For two patients between 16 and 18 years of age, informed consent was obtained from their parents as legally authorized representatives. All interviews were conducted by one psychologist (E.Ö.). The interviewer had extensive experience in administration of the instruments.

Instruments

The Dissociative Disorders Interview Schedule (DDIS) is a structured clinical interview consisting of 131 items. It was designed by Ross et al. to diagnose somatization, major depression, borderline personality disorder and five classes of dissociative disorders according to the DSM-IV.10 The schedule also inquires about a variety of features associated with chronic complex dissociative disorders, including 11 Schneiderian symptoms, 16 secondary features of dissociative identity disorder, and 16 extrasensory experiences. The validity and reliability of the Turkish version (unpublished 1993/1994 translation by Sar V, Yargic LI, Tutkun H) has been reported elsewhere.11

The Dissociative Experiences Scale (DES) is a 28-item self-report instrument developed by Bernstein and Putnam.12 It is not a diagnostic tool but serves as a screening device for chronic dissociative disorders, and has possible scores ranging from 0 to 100. The Turkish version of the scale has good reliability and validity.13 In Turkey a cut-off score of 30 has been shown to be useful in screening dissociative disorders among general psychiatric patients.11

The Clinician-Administered Dissociative States Scale (CADSS) is a 27-item scale with 19 subject-rated items and eight items scored by an observer, and it has excellent reliability and validity.14 All items are assessed using the 0–4 rating scale.

The Scale for Suicide Ideation (SSI) is a 19-item interviewer-rated measure used to evaluate the current intensity of patients' specific attitudes, behaviors and plans to complete suicide.15 The items are rated on a 3-point scale from 0 to 2. The total score can range from 0 to 38. All patients complete the first five items; patients who report a desire to make an active (item 4) or passive (item 5) suicide attempt complete the remaining 14 items. The SSI has demonstrated good psychometric properties for psychiatric outpatients.16

The Somatoform Dissociation Questionnaire is a 20-item self-report instrument that evaluates the severity of somatoform dissociation. It was developed by Nijenhuis et al.17 The Turkish version of the scale has a 1-month test–retest correlation of 0.95. A cut-off point of 35 yielded a sensitivity of 0.84 and a specificity of 0.87 for dissociative disorder diagnosis in a Turkish clinical sample.18

The Spielberger State–Trait Anger Expression Inventory assesses the intensity of feelings of anger (state anger) in seven items, the disposition to experience anger (trait anger) in six items, behaviorally expressed anger (anger-out) in six items, suppressed anger (anger-in) in six items, and self-control of anger behavior (anger control) in six items.19 The Turkish version was validated by Özer.20

The Structured Clinical Interview for DSM-IV Personality Disorders is a semi-structured interview developed by Spitzer et al.21 It serves as a diagnostic instrument for DSM-III-R axis II personality disorders. The section for borderline personality disorder was administered in the present study. The Turkish version of this section has a reliability of 0.95 (κ).22

The Childhood Trauma Questionnaire (CTQ) is a 28-item self-report instrument developed by Bernstein et al. that evaluates emotional, physical, and sexual abuse and physical and emotional neglect during childhood.23 Possible scores for each type of childhood trauma range from 1 to 5. The sum of the scores derived from each trauma type provides the total score, ranging from 5 to 25. Cronbach's alpha for the factors related to each trauma type ranges from 0.79 to 0.94, indicating high internal consistency.23 The unpublished 1996 translation by V. Sar was used in the present study. Previous studies in Turkey supported the validity of this instrument.24,25

Statistical analysis

Frequency and percentage were used for sociodemographic variables. χ2 statistics (Fisher exact test where appropriate) were used for comparison of patients on categorical variables. Mann–Whitney U-test was used to compare the dissociative and non-dissociative groups on continuously distributed variables. Bonferroni correction was used to minimize type I statistical errors. Logistic regression was performed using suicidal ideation as the dependent variable and six clinical items as independent variables. For all statistical analysis the level of significance was set at P = 0.05 unless otherwise indicated.

RESULTS

All patients had a DSM-IV dissociative disorder as determined on DDIS. Twenty-seven patients (65.9%) had dissociative identity disorder and 13 patients (31.7%) had dissociative disorder not otherwise specified. All patients had the lifetime diagnosis of major depressive disorder while 77.5% (n = 31) had a current major depressive episode as well. Seventeen patients (42.5%) had borderline personality disorder and 13 patients (32.5%) had somatization disorder. Thirty-eight patients (95.0%) reported at least one type of childhood abuse and/or neglect. The mean DES score was 42.6 ± 21.2 with a range of 15.0–88.6.

According to evaluation based on Beck Suicidal Ideation Scale (BSI), 15 patients had suicidal ideas or plans of various degree. The mean BSI score of the suicidal group was 19.1 ± 9.0 (range, 7.0–36.0). There was no significant difference on age between suicidal (24.9 ± 5.8) and non-suicidal (26.3 ± 6.5) patients (z = −0.88, P = 0.377). Gender distribution did not differ between the two groups either: 13 versus 18 patients in either group were female, respectively (Fisher's exact test, P = 0.440).

Table 1 demonstrates a comparison between suicidal and non-suicidal dissociative patients on various clinical and mental health history items. After Bonferroni correction, the suicidal group had concurrent somatization disorder and a history of childhood physical abuse more frequently than the remaining patients. The suicidal group had a higher mean number of somatoform and Schneiderian symptoms, borderline personality disorder criteria, secondary symptoms of dissociative identity disorder, and previous suicide attempts. They also had elevated scores on trait (DES) and state (CADSS) dissociation measures (Table 2). The suicidal (mean, 22.7 ± 6.36) and non-suicidal groups (mean, 21.4 ± 5.26) did not differ on age of first contact with psychiatric treatment (z = −0.574, P = 0.566).

Table 1.  Mental health history of dissociative disorder patients vs suicidal ideation status
 Suicidal (n = 15)Not suicidal (n = 25)χ2 (d.f. = 1)P
n%n%
  1. After Bonferroni correction, significance level was set at 0.005.

  2. DDIS, Dissociative Disorders Interview Schedule; SCID-II, Structured Clinical Interview for DSM-IV Personality Disorders.

Concurrent diagnosis      
 Somatization disorder (DDIS)1280.0416.016.000.000
 Borderline personality disorder (SCID-II)1066.7728.05.740.017
 Dissociative identity disorder (DDIS)1386.71456.0Fisher's exact test0.080
 Current major depression (DDIS)1386.71872.0Fisher's exact test0.440
Mental health history items (DDIS)      
 Self-mutilative behavior1493.31768.0Fisher's exact test0.117
 Previous suicide attempt1280.01144.04.970.026
 Childhood physical abuse1386.7936.09.720.002
 Childhood neglect1386.71248.05.980.014
 Childhood sexual abuse1173.31144.03.260.071
 Childhood emotional abuse1280.01560.02.110.147
Table 2.  Characteristics of dissociative patients vs suicidal ideation status
 Suicidal (n = 15)Not suicidal (n = 25)zP
MeanSDMeanSD
  • Mann–Whitney U-test.

  • After Bonferroni correction, significance level is set up at 0.005.

  • CADSS, Clinician-Administered Dissociative States Scale; DES, Dissociative Experiences Scale; SDQ, Somatoform Dissociation Questionnaire.

No. somatic complaints20.16.410.66.3−3.790.000
Secondary symptoms of dissociative identity disorder11.93.36.63.7−3.780.000
No. DSM-IV borderline personality disorder criteria endorsed5.12.02.52.1−3.370.001
No. previous suicide attempts5.77.91.01.5−3.060.002
DES score55.220.335.918.4−2.980.003
CADSS score41.517.323.818.4−2.870.004
Schneiderian symptoms4.33.41.61.4−2.800.005
SDQ51.817.438.412.4−2.500.012
Extrasensory perceptions4.13.11.91.8−2.430.015
Spielberger Anger Scale (trait score)30.57.926.06.2−1.960.050

Table 3 demonstrates childhood trauma scores assessed as a quantitative measure (CTQ). The suicidal group had elevated scores on childhood physical abuse, emotional abuse and emotional neglect as well as total childhood trauma. Childhood physical neglect did not differ between two groups. On logistic regression using suicidal ideation as the dependent variable and six items as covariates (CTQ, CADSS, DES, Schneiderian symptoms, somatization disorder, and borderline personality disorder), only somatization disorder predicted suicidal ideation (Table 4).

Table 3.  Severity of childhood trauma in patients with dissociative disorder vs suicidal ideation status
Childhood traumaSuicidal (n = 15)Not suicidal (n = 25)zP
MeanSDMeanSD
  • Mann–Whitney U-test.

  • CTQ, Childhood Trauma Questionnaire.

Physical abuse2.31.11.40.8−3.470.001
Emotional abuse2.81.01.90.9−2.670.004
Emotional neglect3.61.02.61.0−2.620.009
Sexual abuse2.61.51.60.9−2.610.009
Physical neglect1.80.51.80.3−0.230.819
CTQ total score13.23.99.32.5−3.150.002
Table 4.  Logistic regression with current suicidal ideation as the dependent variable
CovariatesBSEWaldd.f.POR95%CI
  1. CADSS, Clinician-Administered Dissociative States Scale; CI, confidence interval; CTQ, Childhood Trauma Questionnaire; DES, Dissociative Experiences Scale; OR, odds ratio.

Somatization disorder−3.391.316.6910.0100.03(0.00–0.44)
CTQ total score0.370.222.8510.0911.44(0.94–2.20)
Trait dissociation (DES)0.070.051.5510.2131.07(0.96–1.19)
Schneiderian symptoms0.200.280.5110.4741.22(0.71–2.12)
Borderline personality disorder−0.891.230.5210.4700.47(0.04–4.58)
State dissociation (CADSS)−0.020.050.2610.6100.98(0.89–1.07)
Constant−4.853.012.5910.1080.01 

DISCUSSION

A sizable proportion (37.5%) of dissociative patients in the present study had current suicidal ideas. When childhood trauma history and borderline personality disorder diagnosis were controlled for, a concurrent somatization disorder was the only significant predictor of current suicidal ideation among these patients. In the present study the majority (80.0%) of patients with suicidal ideation reported at least one previous suicide attempt. Thus, for most of the patients, the present findings are not relevant for a dissociative state only, but they represent a long-lasting tendency to suicide attempts.

It is well known that a high proportion of dissociative patients have concurrent somatization disorder.26 An epidemiological study conducted on a sample of women from the general population demonstrated that a significant proportion (21.0%) of the participants with somatization disorder reported at least one suicide attempt.27 Constituting a partial overlap, a subgroup (38.9%) of subjects with somatization disorder had the lifetime diagnosis of a dissociative disorder. In a follow-up study on a group of patients with conversion disorder, comorbid dissociative disorder was linked to suicide attempts and self-mutilation alongside childhood trauma history.24 These patients also had somatization disorder more frequently than those without a concurrent dissociative disorder. Thus, these studies suggest that, alongside a history of childhood trauma, a comorbidity between somatization disorder and dissociative disorder may be associated with suicide attempts.

Attempts to define an association between suicidality and somatization are not new in psychiatry. In an effort to develop a strictly medical model of psychiatric disorders, the so-called St Louis school, a research group from Washington University, adopted the earlier work of French physician Pierre Briquet and redefined hysteria (Briquet's syndrome) as a chronic disorder with multiple somatic complaints close to the subsequently developed concept of DSM-IV somatization disorder.28 Researchers following this tradition have also investigated possible genetic links among somatization disorder, antisocial personality disorder, and alcoholism including frequent suicide attempts.29 Like dissociative disorders,30 Briquet syndrome has also been related to childhood trauma.31,32

Ystgaard et al. reported that sexual and physical abuse were independently associated with repeated suicide attempts when the effects of other childhood adversities were controlled for, but they did not evaluate dissociation.33 Self-reported dissociation emerges as a mediating variable in some studies on the relationship between childhood trauma and adult suicidal and self-destructive behavior.34,35 A number of studies have found bivariate relationships between dissociation and self-harm or suicidality; in some studies this effect persists when childhood trauma history is controlled for35–37; in others, controlling for childhood trauma diminishes or eliminates the association.34,38–40

Attempts to understand the relationship between dissociative disorders and suicidality are complicated by the extremely high comorbidity rate of these disorders, including co-occurrence with borderline personality disorder.41 Borderline personality disorder is known to carry its own elevated risk of suicidal behavior.42,43 In a recent study, however, Foote et al. demonstrated among psychiatric outpatients that dissociative disorder was associated with suicidality while borderline personality disorder was not.1 Interestingly, in another study, somatization disorder was associated with suicide attempts when the effects of both a comorbid major depressive disorder and a comorbid personality disorder were statistically controlled for.44

Given the fact that somatization disorder and dissociative disorders are frequently observed among patients with borderline personality disorder,25,45 an explanation beyond personality disorder seems to be warranted for suicidality in this spectrum of patients. In a study on patients with borderline personality disorder, affective instability, identity disturbance, and impulsivity predicted suicidal behavior.43 Only affective instability and childhood sexual abuse were significantly associated with suicide attempts. Dieserud et al. reported that low self-appraised problem-solving capacity and general self-efficacy predicted repetition of suicide attempt.44 No significant effects were found for depression, hopelessness or self-esteem. They retained their predictive power even when controlling for age, sex, previous suicide attempt, suicide intention and medical risk.

Recent studies suggest that both somatization and suicidality are independently associated with insecure attachment style originating from developmental traumas.46,47 Both persistent multiple somatic complaints and chronic suicidality may point to a resistance to or even sabotage of, treatment. From an attachment theoretical perspective, suicide attempts by adults are protests against the experience of ‘not existing in anyone else's mind’;48 that is, being not considered by others as much as needed. This may be also valid for persistent somatic complaints. Clinician insight into these associations may have crucial importance in management of suicidality throughout treatment in patients with dissociative disorders. Last but not least, the presence of a complex dissociative disorder in patients with severe and persistent somatic complaints should alert the clinician to the possibility of suicidal ideation.

Ancillary