Major depressive and post-traumatic stress disorder comorbidity in female victims of intimate partner violence

Journal of Affective Disorders 66 (2001) 133–138 www.elsevier.com / locate / jad

Research report

Major depressive and post-traumatic stress disorder comorbidity in female victims of intimate partner violence Murray B. Stein

a,b ,

*, Colleen Kennedy a,b

a

b

VA San Diego Healthcare System, San Diego, CA, USA Department of Psychiatry, University of California San Diego, La Jolla, CA, USA Received 18 April 2000; accepted 26 July 2000

Abstract Background & Methods: Victims of intimate partner violence (IPV) often develop psychiatric disorders. We examined the extent and correlates of comorbidity between two of the disorders most frequently linked to trauma – major depressive disorder (MDD) and post-traumatic stress disorder (PTSD) – in a group of 44 women who were victims of IPV within the preceding 2 years. Results: MDD (68.2%) and PTSD (50.0%) were highly prevalent on a lifetime basis in female victims of IPV. On a current basis, MDD (18.2%) and IPV-related PTSD (31.8%) were more frequently comorbid (42.9% of cases of current IPV-related PTSD also had MDD) than would be expected by chance (P , 0.001). Most cases of current MDD occurred in persons who also had current IPV-related PTSD. Severity of depressive and PTSD symptoms were highly correlated (r 5 0.84). Although women with PTSD were significantly more disabled than women without PTSD, persons with comorbid PTSD and MDD were not significantly more disabled than those with PTSD alone. Limitations: Crosssectional study; entry criteria for study may limit generalizability. Conclusions: PTSD and MDD symptoms are frequently seen in the aftermath of IPV, and often co-occur. The usefulness of the distinction between PTSD and MDD in this context remains to be determined, both in terms of diagnostic classification and prognostic implications.  2001 Elsevier Science B.V. All rights reserved. Keywords: Domestic violence; Intimate partner violence; Major depressive disorder; Post-traumatic stress disorder

1. Introduction Domestic abuse, also known as intimate partner violence (IPV), is a major public health problem of alarming proportions (Bell et al., 1996). A recent *Corresponding author. Tel.: 11-858-622-6112; fax: 11-858450-1491. E-mail address: [email protected] (M.B. Stein).

survey of a nationally representative sample of women found that 8% of women who were married or living with a domestic partner at the time of the interview, said they had been physically abused by their partners during the past 12 months (Plichta, 1996). The severity of this type of abuse is further reflected in a 1994 statistic showing that 17% of all persons treated in emergency rooms in the United States had been injured by an intimate partner (Rand,

0165-0327 / 01 / $ – see front matter  2001 Elsevier Science B.V. All rights reserved. PII: S0165-0327( 00 )00301-3

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1997). IPV often results not only in serious physical injury but also puts women at risk for the development of mental disorders (Golding, 1999). Among the most commonly identified sequelae of IPV are post-traumatic stress disorder (PTSD) (Astin et al., 1993; Dutton, 1992; Gleason, 1993; Kemp et al., 1995; Saunders, 1994) and major depressive disorder (MDD) (Campbell et al., 1997; Gleason, 1993). Extensive comorbidity between PTSD and MDD is the norm in studies of various traumatized groups, including persons exposed to combat (Shalev et al., 1998; Southwick et al., 1991), disasters (Green and Lindy, 1994), and IPV (Cascardi et al., 1999). Community studies also demonstrate a strong link between these two disorders, with approximately 35–50% of cases of PTSD in the general population being comorbid with MDD (Breslau et al., 1997; Breslau et al., 1998; Kessler et al., 1995). The purpose of the present investigation was to further evaluate the co-occurrence and correlates of PTSD and MDD in female victims of IPV. In addition to determining the extent of comorbidity, principal goals of this study were to identify possible indicators of comorbidity, and to describe the impact of comorbidity on functioning.

2. Methods

2.1. Subjects Forty-four female victims of intimate partner violence (IPV) were recruited through the use of advertisements from agencies that provide services to victims of domestic abuse and from community medical clinics. All participants were part of a larger study examining the psychological and neurobiological effects of trauma in women. The IPV participants were victims of physical and / or sexual abuse by an intimate partner, and they had all extricated themselves from their abusive relationship at least 4 weeks, but no longer than 2 years, prior to enrollment in the study. All participants were English speaking and had at least an 8th grade reading ability. No participant had a history of neurological illness, head injury as indicated by loss of conscious-

ness greater than 10 min, learning disability, or a history of psychosis. Furthermore, individuals were excluded from the study if any of the following applied: use of any psychotropic medication within 6 weeks prior to participation; use of oral or intramuscular steroids within the past 4 months; drug or alcohol abuse or dependence within the past year; or a history of alcohol abuse for a period of greater than 2 years in the past, as assessed by the Addiction Severity Index (McClellan et al., 1985). A total of 184 IPV victims contacted us in response to our posted advertisements and were screened for eligibility. Of these, 125 were deemed ineligible for one or more of the following most common reasons: English not their first language; still in the abusive relationship; extensive substance abuse history; serious head injury; current psychotropic use. Of 59 eligible participants, 15 chose not to participate or did not show up for the assessments, leaving the current group of 44 participants with a history of recent IPV. Study participants ranged in age from 19 to 49 years (M 5 34.07, S.D. 5 9.25) and had an average of 12.70 years (S.D. 5 2.25) of education. Hollingshead scores (Hollingshead, 1975), where higher scores reflect higher socioeconomic status, were M 5 31.86, S.D. 5 12.67. IPV participants were 48% Caucasian, 22% African American, 14% Hispanic, 2% Native American, and 14% were from other ethnic backgrounds.

2.2. Procedures To assess presence or absence of PTSD and PTSD severity, participants were administered the Clinician Administered PTSD Scale for DSM-IV (CAPS) (Blake et al., 1995), with questions directed specifically to experiences of domestic violence. High scores on the CAPS indicate greater levels of PTSD symptom severity. The CAPS Criterion F items were used to examine overall level of functioning in daily living. Participants were also administered the PTSD module of the Structured Clinical Interview for the DSM-IV (SCID-P) (First et al., 1997) to assess presence or absence of lifetime PTSD for any lifetime trauma other than domestic abuse. The

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MDD, Panic Disorder, and Generalized Anxiety Disorder modules of the SCID-P were also administered to assess for the presence of these diagnoses. The Impact of Event Scale-Revised (IES-R) (Weiss and Marmar, 1997), a 22-item self-report measure, was administered to examine severity of PTSD symptoms over the past week. Subjects were instructed to respond to each item, based on a fivepoint Likert scale ranging from 0 5 not at all to 4 5 extremely, regarding their experience with IPV. Severity of intimate partner violence was measured using the revised version of the Conflict Tactics Scale (CTS-2) (Straus et al., 1996), a 39item self-report measure with five subscales (Negotiation, Psychological Aggression, Physical Assault, Sexual Coercion, and Injury) assessing various aspects of the domestic abuse experience. Level of depression was assessed in all subjects, using the Center for Epidemiologic Studies-Depression Scale (CES-D) (Radloff, 1977), a 20-item selfreport measure examining depressive symptoms within the past week.

2.3. Statistical analyses The proportion of subjects meeting DSM-IV criteria for the various diagnoses under consideration, are reported using descriptive statistics. The association between MDD and IPV-related PTSD categorical diagnoses was examined using the Chisquare test with continuity correction. The association of continuous measures of symptoms and abuse severity were examined using Pearson’s correlation coefficient. We next tested the hypothesis that more severe abuse would be associated with a greater likelihood of having comorbid IPV-related PTSD (from any kind of trauma, including IPV) 1 MDD (rather than IPV related PTSD alone) using hierarchical logistic regression. We tested the hypothesis that participants with comorbid PTSD (from any kind of trauma, including IPV) 1 MDD would have more severe PTSD symptoms and poorer functioning than those with PTSD alone by comparing IES-R, CAPS-total and the CAPS functioning items in the two groups with Student’s t-tests. All statistical tests were two-

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tailed, and P values , 0.05 were considered statistically significant.

3. Results

3.1. Prevalence of PTSD and other disorders The prevalence of PTSD and other DSM-IV disorders assessed in the study is shown in Table 1. PTSD was the most common disorder on a current (past 30 days) basis, but major depression was the most common on a lifetime basis. Panic disorder was somewhat less common both on a lifetime and especially on a current basis. Generalized anxiety disorder, which was assessed on only a lifetime basis, was the least common of the disorders assessed.

3.2. IPV-related PTSD and MDD comorbidity Six subjects (13.6%) had current comorbid IPVrelated PTSD 1 MDD. The co-occurrence of current PTSD and MDD took place on what was significantly more than a chance basis (continuity-corrected Chi-square 5 8.39, df 5 1, P , 0.004); six of 14 subjects (42.9%) with current IPV-related PTSD also had MDD, whereas only one of 30 subjects without current IPV-related PTSD (3.3%) also had MDD. On a lifetime basis, cases of MDD were equally distributed among women with PTSD (72.7%) and women without PTSD (63.6%; continuity-corrected Chisquare 5 0.1, df 5 1, P , 0.75 [ns]). Both cases of

Table 1 Prevalence of assessed DSM-IV disorders in female victims violence (N544) DSM-IV diagnosis

N (%)

Current IPV-related PTSD Current PTSD (from any trauma) Lifetime PTSD (from any trauma) Current major depressive disorder Lifetime major depressive disorder Current panic disorder Lifetime panic disorder Lifetime generalized anxiety disorder

14 (31.8%) 19 (45.2%)a 22 (50.0%) 8 (18.2%) 30 (68.2%) 2 (4.5%) 6 (13.6%) 2 (4.5%)

a

Not assessed in two subjects; denominator is 42 subjects.

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current panic disorder were comorbid with IPVrelated PTSD.

3.3. Relationship between IPV severity and severity of current IPV-related PTSD and depressive symptoms Severity of current IPV-related PTSD (as measured by the CAPS) and depressive symptoms (as measured by the CES-D) were strongly correlated (r5 0.84, df 537, P,0.001). Interestingly, although a modest association was seen between severity of the domestic abuse as measured by the various CTS-2 subscales and severity of IPV-related PTSD symptoms (r values range from 0.40 to 0.43, all P values ,0.05, for the Psychological Aggression, Physical Assault, Sexual Coercion, and Injury subscales), no such relationship was seen for depressive symptoms (r values range from 0.01 to 0.15, none statistically significant).

3.4. Indicators of PTSD and comorbid PTSD1 MDD We hypothesized that more severe IPV would be associated with a greater likelihood of having developed comorbid IPV-related PTSD1MDD, rather than IPV-related PTSD alone. Hierarchical logistic regression, entering the two CTS-2 subscales (Phys-

ical Assault and Injury, respectively) we believed would be most strongly indicative of the distinction between PTSD alone vs. comorbid PTSD1MDD, did not turn out to have significant explanatory power (Chi-square for the model51.26, df 52, P. 0.50 [ns]).

3.5. Severity of symptoms and IPV in comorbid cases Scores on measures of Current PTSD symptoms (CAPS and the IES-R), depressive symptoms (CESD), and severity of the domestic abuse experience itself (CTS-2) are shown in Table 2. In this table, victims of IPV are characterized as either having Current PTSD without MDD (N512), Current PTSD with MDD (N57), or No Current PTSD. We hypothesized that women with current comorbid PTSD and MDD would have more severe PTSD symptoms than persons with PTSD alone. CTS-2 scores are included for information purposes only, as we did not test for differences in order to reduce the number of comparisons being made. For the same reason, we did not test for differences with the group who did not have PTSD, as these are obvious. In fact, the two PTSD groups with and without comorbid MDD did not differ significantly from one another on total CAPS or CES-D scores.

Table 2 Symptom and domestic abuse severity in female victims of intimate partner violence a Severity

Current PTSD (-MDD) mean (S.D.) (N512)

Current PTSD1MDD mean (S.D.) (N57)

No Current PTSD mean (S.D.) (N522)

CAPS total IES-R CES-D CTS-2 negotiation CTS-2 psychological aggression CTS-2 physical assault CTS-2 sexual coercion CTS-2 injury CAPS overall disability CAPS social disability CAPS occupational disability

60.5 42.7 28.6 40.7 13.4 88.9 34.2 26.1 2.7 2.5 2.1

74.3 54.7 39.0 43.6 82.4 76.7 30.1 32.1 2.7 2.4 2.9

24.9 (16.1) 19.3 (13.8) 14.1 (9.5) 39.8 (37.4) 65.7 (56.0) 48.6 (61.04) 20.0 (39.8) 11.8 (15.8) 1.4 (0.7) 1.5 (1.4) 0.9 (1.2)

a

(23.1) (20.8) (12.9) (31.3) (74.3) (96.6) (54.1) (32.6) (0.9) (1.1) (1.8)

Samp1e sizes vary for some measures due to missing data.

(18.5) (13.4) (8.3) (41.8) (55.8) (84.4) (40.0) (44.1) (1.1) (1.5) (1.5)

M.B. Stein, C. Kennedy / Journal of Affective Disorders 66 (2001) 133 – 138

3.6. Functioning in IPV-related PTSD and comorbid cases Using the CAPS Section F items to assess functioning, we compared scores of women without PTSD or MDD, with PTSD alone, and with comorbid PTSD1MDD (these scores are also shown in Table 2). ANOVA revealed significant group differences in Occupational Functioning (F 55.40, df 5 2,33, P,0.01) and Overall Functioning (F 510.08, df 52,33, P,0.001), but not Social Functioning (F 52.25, df 52,33, P,0.14). Post-hoc testing showed that women with current PTSD (grouping together those with and without current comorbid MDD) reported poorer Occupational (P,0.05) and Overall Functioning (P,0.005) than women without PTSD. The PTSD alone and comorbid PTSD1MDD groups did not differ significantly on these indices (all P values .0.05), but power to detect such differences was very low (,0.30).

4. Discussion We found that many women who are victims of IPV experience major depression and PTSD, often in combination. Other anxiety disorders such as panic and generalized anxiety disorder appear to be much less common. These findings are consistent with most other studies confirming the high rates of psychopathology in women exposed to the psychological and physical trauma of battering (for review see (Golding, 1999)). In this study, nearly all cases (six of eight or 75%) of current major depression occurred in the context of current IPV-related PTSD. In other words, it was rare to see major depression alone. This finding is consistent with other studies suggesting that major depression is often a later-occurring ‘complication’ of PTSD in victims of trauma (Mellman et al., 1992). It is also consistent with the observation that the causal pathways to PTSD and major depression in the wake of exposure to trauma are not independent (Breslau et al., in press). Additional prospective, longitudinal studies are required to understand the temporal and etiologic relationships between trauma, PTSD and major depression over the life course.

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Ratings of PTSD and depression were highly correlated in victims of IPV. At this juncture, we might speculate that PTSD and MDD symptoms are highly intertwined in the aftermath of some sorts of trauma (such as IPV), and that the additional diagnosis of MDD adds little to the explanation of functional outcomes. But we must also consider the strong possibility that our failure to find differences might reflect type I error, and that larger samples will be needed to detect relatively subtle betweengroups variations in functioning. This is an area in need of further investigation. We hypothesized that comorbid MDD and PTSD would be more likely to occur in women who had experienced more serious battering, but this hypothesis was not upheld. It is possible that our failure to see these expected differences was due to the small sample sizes in these two groups and the resulting low power to detect differences. Participants were drawn from community agencies providing services to battered women and from general medical clinics in the community, rather than from psychiatric or behavioral health service agencies, in an attempt to maximize the generalizability of our results. Still, we must acknowledge that our sample may not be representative of most women with IPV, in particular because of our exclusion of persons with recent drug or alcohol abuse, and of persons with serious head injury. Both of these sequelae of IPV are common enough that additional studies would be needed to determine whether or not our findings can be extended to these groups. In summary, we found that PTSD and MDD frequently occur in the aftermath of intimate partner violence. Moreover, MDD following IPV tends to occur predominantly in persons who are also experiencing IPV-related PTSD, raising questions about the causal pathways to these two disorders. Indeed, given the extensive symptom and syndromal overlap, one must wonder whether PTSD and MDD occuring in the wake of traumatic stress should be considered distinct disorders at all. To inform this debate, it will be useful to test an alternate model positing a cascade of symptoms triggered by the traumatic experiences – and therefore belonging to a single disorder, rather than the two-disorder model implied by DSM-IV criteria. Future studies should address this issue by prospectively following victims of IPV,

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carefully documenting the temporal onset of different dimensions of these syndromes.

Acknowledgements This study was supported by a VA Merit Review grant to Dr. Stein. The authors are grateful to Leila Tarokh for assistance with data management and to Traci Bergthold, M.A. for assistance with diagnostic interviews. We also wish to express our appreciation to the San Diego YWCA and the San Diego Center for Community Solutions for their assistance with this project.

References Astin, M.C., Lawrence, K.J., Foy, D.W., 1993. Post-traumatic stress disorder among battered women: risk and resiliency factors. Violence and Victims 8, 17–29. Bell, R., Duncan, M., Eilenberg, J., Fullilove, M., Hem, D., Innes, L., Mellman, L., Panzer, P. (Eds.), 1996. Violence Against Women in the United States: A Comprehensive Background Paper, 2nd Edition. Columbia University, New York, NY, pp. 1–107. Blake, D.D., Weathers, F.W., Nagy, L.M., Kaloupek, D.G., Gusman, F.D., Chamey, D.S., Keane, T.M., 1995. The development of a clinician-administered PTSD scale. J Traum. Stress 8, 75–90. Breslau, N., Davis, G.C., Peterson, E.L. and Schultz, L. (in press) A second look at comorbidity in victims of trauma: the posttraumatic stress disorder-major depression connection. Biol. Psychiatry. Breslau, N., Davis, G.C., Peterson, E.L., Schultz, L., 1997. Psychiatric sequelae of post-traumatic stress disorder in women. Arch. Gen. Psychiatry 54, 81–87. Breslau, N., Kessler, R.C., Chilcoat, H.D., Schultz, L.R., Davis, G.C., Andreski, P., 1998. Trauma and post-traumatic stress disorder in the community. Arch. Gen. Psychiatry 55, 626– 632. Campbell, J.C., Kub, J., Bellcnap, R.A., Templin, T.N., 1997. Predictors of depression in battered women. Violence Against Women 3, 271–293. Cascardi, M., O’Leary, K.D., Schlee, K.A., 1999. Co-occurrence and correlates of post-traumatic stress disorder and major depression in physically abused women. J. Family Violence 14, 227–249. Dutton, M.A., 1992. Assessment and treatment of post-traumatic stress disorder among battered women. In: Foy, D.W. (Ed.), Treating PTSD: Cognitive Behavioral Strategies. Guilford Press, New York, pp. 69–97. First, M.B., Spitzer, R.L., Gibbon, M., Williams, J.B.W., 1997.

Structured Clinical Interview for DSM-IV Axis I Disorders – Clinician Version (SCID-1). American Psychiatric Press, Inc, Washington, D.C. Gleason, W.J., 1993. Mental disorders in battered women: An empirical study. Violence and Victims 8, 53–68. Golding, J.M., 1999. Intimate partner violence as a risk factor for mental disorders: a meta-analysis. J. Family Violence 14, 99– 132. Green, B.L., Lindy, J.D., 1994. Post-traumatic stress disorder in victims of disasters. Psychiatr. Clin. North Am. 17, 301–309. Hollingshead, A.B., 1975. Four factor index of social status. Unpublished manuscript, Yale University, New Haven, CT. Kemp, A., Green, B.L., Hovanitz, C., Rawlings, E.I., 1995. Incidence and correlates of post-traumatic stress disorder in battered women: shelter and community samples. J. Interpersonal Violence 10, 43–55. Kessler, R.C., Sonnega, A., Bromet, E., Hughes, M., Nelson, C.B., 1995. Post-traumatic stress disorder in the National Comorbidity Survey. Arch. Gen. Psychiatry 52, 1048–1060. McClellan, A.T., Luborsky, A., Cacciola, J., Griffith, J., Evans, F., Barr, H.L., O’Brien, C.P., 1985. New data from the Addiction Severity Index: reliability and validity in three centers. J. Nervous Mental Disord. 173, 412–423. Mellman, T.A., Randolph, C.A., Brawman-Mintzer, O., Flores, L.P., Milanes, F.J., 1992. Phenomenology and course of psychiatric disorders associated with combat-related posttraumatic stress disorder. Am. J. Psychiatry 149, 1568–1574. Plichta, S.B., 1996. Violence and abuse: implications for women’s health. In: Falik, M.M., Collins, K.S. (Eds.), Women’s Health: The Commonwealth Fund Survey. John Hopkins University Press, Baltimore, MD, pp. 237–270. Radloff, L.S., 1977. The CES-D scale: a self-report depression scale for research in the general population. Psychol. Measur. 1, 385–401. Rand, M.R., 1997. Violence-related injuries treated in hospital emergency departments. Bureau of Justice Statistics. Special Report. Washington, DC: US Department of Justice. Saunders, D.G., 1994. Post-traumatic stress symptom profiles of battered women: comparison of survivors in two settings. Violence and Victims 9, 31–44. Shalev, A.Y., Freedman, S., Pen, T., Brandes, D., Sahar, T., Orr, S.P., Pitman, R.K., 1998. Prospective study of post-traumatic stress disorder and depression following trauma. Am. J. Psychiatry 155, 630–637. Southwick, S.M., Yehuda, R., Giller, E.L.J., 1991. Characterization of depression in war-related post-traumatic stress disorder. Am. J. Psychiatry 148, 179–183. Straus, M., Hamby, S.L., Boney-McCoy, S.B., Sugarman, D.B., 1996. The Revised Conflict Tactics Scales (CTS2): Development and preliminary psychometric data. J. Family Issues 17, 283–316. Weiss, D.S., Marmar, C.R., 1997. The impact of events scalerevised. In: Wilson, J.P., Keane, T.M. (Eds.), Assessing Psychological Trauma and PTSD. Guilford Press, New York, NY, pp. 577–591.