- Email: [email protected]
OND veterans
Journal of Affective Disorders 135 (2011) 310–314
Contents lists available at ScienceDirect
Journal of Affective Disorders j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / j a d
Preliminary communication
Examining the dimensionality of combat-related posttraumatic stress and depressive symptoms in treatment-seeking OEF/OIF/OND veterans☆ Jack Tsai a, b,⁎, Robert H. Pietrzak b, c, Steven M. Southwick b, c, Ilan Harpaz-Rotem b, c a b c
VA New England Mental Illness Research, Education, and Clinical Center, West Haven, CT, United States Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States National Center for Posttraumatic Stress Disorder, VA Connecticut Healthcare System, West Haven, CT, United States
a r t i c l e
i n f o
Article history: Received 10 June 2011 Accepted 29 June 2011 Available online 22 July 2011 Keywords: Posttraumatic stress disorder Major depressive disorder Substance abuse Coping
a b s t r a c t Background: This study examined the factor structure of two of the most commonly used screening measures of posttraumatic stress disorder and depression in 164 treatment-seeking veterans who served in Operations Enduring Freedom/Iraqi Freedom/New Dawn (OEF/OIF/ OND). Methods: Exploratory factor analysis was used to assess the dimensionality of items from the Posttraumatic Stress Disorder Checklist–Military Version (PCL-M) and the Patient Health Questionnaire-9 (PHQ-9). Regression analyses were then conducted to examine associations between factor scores of the resulting factor solution and measures of alcohol use, cognitive coping, psychological resilience, social support, and healthcare utilization. Results: A four-factor solution was found that consisted of clusters of symptoms reflecting reexperiencing/avoidance, detachment/numbing, hopelessness/depression, and bodily disturbance. Scores on the detachment/numbing factor were uniquely related to alcohol use, whereas scores on the hopelessness/depression factor was uniquely associated with emergency room visits. Compared to conventional PCL-M and PHQ-9 total scores, the fourfactor solution explained 2 to 10% more variance in scores on measures of alcohol use, cognitive coping, psychological resilience, social support, and healthcare utilization. Limitations: This study was limited by a small sample size and cross-sectional design. Conclusions: Combat-related posttraumatic stress disorder and depressive symptoms in treatment-seeking OEF/OIF/OND veterans may be better conceptualized by four dimensions of reexperiencing/avoidance, detachment/numbing, hopelessness/depression, and bodily disturbance symptoms. This symptom structure may provide greater utility when examining other outcomes of interest in this population. Published by Elsevier B.V.
Symptoms of posttraumatic stress disorder (PTSD) and depression are among the most common mental health complaints of military personnel who have served in Operation Enduring Freedom/Operation Iraqi Freedom/Operation New
☆ Funding for this study was provided by the Clinical Neurosciences Division of the National Center for Posttraumatic Stress Disorder, and a private donation. ⁎ Corresponding author at: VACT, 950 Campbell Ave., 151D, West Haven, CT 06516, United States. Tel.: + 1 203 932 5711x2090. E-mail address: [email protected] (J. Tsai). 0165-0327/$ – see front matter. Published by Elsevier B.V. doi:10.1016/j.jad.2011.06.057
Dawn (OEF/OIF/OND) (Cassels, 2010; Hoge et al., 2006; Tanielian and Jaycox, 2008). Two of the most commonly used screening instruments for PTSD and depression in this population are the PTSD Checklist–Military version (PCL-M; Weathers et al., 1991) and the Patient Health Questionnaire-9 (PHQ-9; Kroenke and Spitzer, 2002), respectively. While these instruments are often interpreted independently, a growing number of studies have found considerable overlap between symptoms of PTSD and depression (Gros et al., 2010; Resick and Miller, 2009; Rosen et al., 2008; Watson, 2005). This has led some researchers to question the utility of
J. Tsai et al. / Journal of Affective Disorders 135 (2011) 310–314
the current diagnostic classification system and measures based on this system in assessing psychopathology. For example, a recent exploratory factor analytic study of PTSD and major depression in treatment-seeking veterans found that non-specific symptoms of PTSD, referred to as dysphoria or emotional numbing symptoms, were more strongly correlated with symptoms of depression than specific symptoms of PTSD, such as reexperiencing and avoidance symptoms (Gros et al., 2010). Similar findings have been observed in samples of Gulf War veterans, Canadian military veterans, and vehicular accident survivors (Elhai et al., 2011; Grant et al., 2008; Simms and Watson, 2002). Taken together, these findings underscore the importance of examining alternative conceptualizations of how PTSD and depression symptoms may manifest in clinical samples. To date, little research has examined how specific and non-specific symptoms of PTSD and depression may be differentially related to other variables of interest. Given that dysphoria/emotional numbing symptoms of PTSD involve a loss of interest in activities, detachment from others, and restricted range of affect (Feeny et al., 2000), these symptoms may be particularly strongly related to psychosocial functioning. Indeed, available data suggests that, relative to reexperiencing and avoidance symptoms, dysphoria/ emotional numbing symptoms of PTSD are more strongly associated with concomitant psychiatric symptoms, alcohol use problems, greater perceived stigma, decreased psychological resilience, lower life satisfaction, as well as greater mental healthcare utilization (Palmieri and Fitzgerald, 2005; Palmieri et al., 2007; Pietrzak et al., 2010). The current study aimed to extend previous research by exploring (1) the factor structure of two of the most commonly used screening measures of PTSD and depression in a sample of treatment-seeking OEF/OIF/OND veterans; and (2) examining how the resulting factor solution relates to psychosocial measures previously linked to non-specific symptoms of PTSD (i.e., alcohol use, cognitive coping, psychological resilience, social support, and healthcare utilization; Palmieri and Fitzgerald, 2005; Palmieri et al., 2007; Pietrzak et al., 2010). We hypothesized that an exploratory factor analysis would yield a factor solution characterized by both specific and non-specific symptoms of PTSD; and that non-specific symptoms (i.e., dysphoria/ numbing) would be uniquely associated with poorer psychosocial status and greater mental healthcare utilization compared to other PTSD and depression symptoms. 1. Measures 1.1. PTSD and depression Combat-related PTSD symptoms were assessed with the PTSD Checklist-Military version (PCL-M; Weathers et al., 1991). The PCL-M is a 17-item screening instrument based on DSM-IV criteria for PTSD. In this study, there was excellent internal consistency with Cronbach's alpha = .92. Depressive symptoms were assessed with the Patient Health Questionnaire-9 (PHQ-9; Kroenke and Spitzer, 2002). The PHQ-9 is a 9-item self-report screening instrument for depression. In this study, there was good internal consistency with alpha = .89.
311
1.2. External measures Alcohol use was assessed with a 4-item instrument called the CAGE questionnaire (Ewing, 1984). The CAGE is used to identify possible alcohol problems and has been used in hundreds of studies. This study found adequate internal consistency on this measure, with alpha = .70. Psychological resilience was assessed using the 25-item Connor–Davidson Resilience Scale (CD-RISC; Connor and Davidson, 2003). Excellent internal consistency was found for the total scale, alpha = .95. Cognitive coping was assessed with the Thought Control Questionnaire (TCQ; Wells and Davies, 1994; Wells and Reynolds, 1999). The TCQ is a 30-item measure that assesses the frequency of the use of thought control strategies on six separate scales: worry, self-punishment, reappraisal, behavioral distraction, cognitive distraction, and social control. In this study, there was adequate internal consistency for each of the scales with alpha = .78, .83, .55, .65, .75, and .58, respectively. Postdeployment Social Support Scale (PSSS) is a 15-item measure from the Deployment Risk and Resilience Inventory (King et al., 2006; Vogt et al., 2008) that assesses support after military deployment. In this study, there was good internal consistency with alpha = .86. Healthcare utilization was assessed with four questions that asked participants how many visits they made in the past six months to a primary care provider, to an emergency room, to a mental health professional for counseling, and to a mental health professional for medication. All measures were administered after participants gave informed consent and procedures were approved by the local institutional review board. 1.3. Data analysis To examine potential overlap between items on the PHQ-9 and PCL-M, a principal components factor analysis was conducted that specified a priori two factors on the 26 items from the PHQ-9 and the PCL-M. Both orthogonal (varimax) and oblique (promax) rotations were examined. An exploratory principal components factor analysis was then conducted with both varimax and promax rotations. Pearson correlations, using an adjusted significance level of p b .01 to control for Type I error, were computed between factor scores and measures of healthcare utilization, coping, alcohol use, resilience, and social support. Two series of regression analyses were then conducted; the first used conventional PHQ-9 and PCL-M total scores as independent variables, the second used factor scores from the exploratory factor analysis as independent variables. Multiple regression was used for continuous dependent variables and logistic regression was used for dichotomous measures of healthcare use. Adjusted total R 2 was calculated in multiple regression and Nagelkerke (1991) total R 2 in logistic regression analyses. 2. Results A factor analysis with a varimax rotation specifying two factors on items from the PHQ-9 and the PCL-M accounted for 56.84% of the total variance. Most items loaded highest on
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J. Tsai et al. / Journal of Affective Disorders 135 (2011) 310–314
Table 1 Exploratory factor analysis of items from the Patient Health Questionnaire-9 (PHQ-9) and the Posttraumatic Stress Disorder Checklist—Military version (PCL-M). Items
Factor 1: Factor 2: Factor 3: Factor 4: reexperiencing/avoidance detached/numbness hopelessness/depression bodily disturbance
Having physical reactions when something reminded you of a SME (PCL-M) Suddenly acting or feelings as if the SME was happening again (PCL-M) Avoiding thinking about or talking about or having feelings related to a SME (PCL-M) Feeling very upset when something reminded you of a SME (PCL-M) Repeated, disturbing memories, thoughts, or images of a SMEa (PCL-M) Repeated, disturbing dreams of a SME (PCL-M) Avoiding activities or situations because they reminded you of a SME (PCL-M) Feeling jumpy or easily startled (PCL-M) Being “super-alert” or watchful or on guard (PCL-M) Trouble remembering important parts of a SME (PCL-M) Feeling distant or cut off from other people (PCL-M) Loss of interest in activities you used to enjoy (PCL-M) Feeling emotionally numb or unable to have loving feelings (PCL-M) Little interest or pleasure in doing things (PHQ9) Feeling irritable or having angry outbursts (PCL-M) Having difficulty concentrating (PCL-M) Thoughts you would be better off dead or hurting yourself (PHQ9) Feeling bad about yourself (PHQ9) Trouble concentrating on things (PHQ9) Moving or speaking slowly or being fidgety or restless (PHQ9) Feeling down, depressed, or hopeless (PHQ9) Feeling as if your future will somehow be cut short (PCL-M) Trouble falling or staying asleep, or sleeping too much (PHQ9) Trouble falling or staying asleep (PCL-M) Poor appetite or overeating (PHQ9) Feeling tired or having little energy (PHQ9)
.79
.14
.20
.17
.77
.19
.22
.11
.77
.33
.06
.04
.75
.42
.16
.16
.75
.01
.21
.35
.74 .74
.05 .31
.17 .25
.39 −.01
.61 .55 .49 .24 .24 .29
.48 .48 .27 .77 .74 .72
.08 −.08 .40 .28 .31 .33
.22 .29 −.08 .18 .08 .15
.08 .36 .34 .11
.69 .65 .61 .13
.38 .14 .30 .72
.28 .22 .19 .03
.25 .17 .22
.29 .21 .37
.70 .61 .58
.13 .33 .20
.10 .40
.54 .47
.56 .51
.32 .03
.20
.19
.14
.86
.39 .08 .14
.25 .21 .41
.05 .48 .41
.75 .59 .52
a
SME = Stressful Military Experience.
their parent scale. However, items 9 (“Loss of interest in activities you used to enjoy”), 10 (“Feeling distant or cut off from other people”), 11 (“Feeling emotionally numb or unable to having loving feelings”), 12 (“Feeling as if your future will somehow be cut short”), 14 (“feeling irritable or having angry outbursts”), and 15 (“having difficulty concentrating”) from the PCL-M had higher loadings on the PHQ-9 factor. None of the PHQ-9 scale items had higher loadings on the PCL-M factor. A promax rotation yielded similar results. An exploratory factor analysis with a varimax rotation of items from the PHQ-9 and the PCL-M revealed four factors with eigenvalues over 1.0, which were labeled Factor 1: Reexperiencing/Avoidance, Factor 2: Detached/Numbness, Factor 3: Hopelessness/Depression, and Factor 4: Bodily Disturbance (Table 1). These four factors accounted for 67.23% of the total variance. A factor analysis with a promax rotation yielded similar results, except that item 16 on the PCL-M (“being ‘super-alert’ or watchful or on guard”) had a slightly higher loading on the 2nd factor instead of the 1st factor (loading = .48 and .43) and item 2 of the PHQ-9 (“feeling down, depressed, or hopeless”) had a slightly higher loading on the 2nd factor than the 3 rd factor (loading = .49 and .43).
Correlations between orthogonal factor scores and measures of healthcare use, coping, alcohol use, resilience, and social support showed that Factor 1: Reexperiencing/Avoidance was significantly and solely associated with higher TCQ: Social Control scores (r = .27, p b .01). Factor 2: Detached/ Numbness was significantly and solely associated with higher scores on the CAGE (r = .26, p b .01). Factor 3: Hopelessness/ Depression was significantly and solely associated with a greater number of emergency room visits (r = .23, p b .01), psychotherapy visits (r = .25, p b .01), and lower TCQ: Cognitive Distraction scores (r = −.32, p b .001). Factor 2: Detached/Numbness (r = −.31, p b .01) and Factor 3: Hopelessness/Depression (r = −.46, p b .01) were both associated with lower scores on the CD-RISC score. All factors, except Factor 4: Bodily Reaction, were significantly correlated with higher scores on TCQ: Worry (r = .27, .37, and .26, respectively, all p b .01) and TCQ: Punishment (r = .32, .22, .39, p b .01), and lower scores on the PSSS score (r = −.28, −.28, −.25, p b .01). When the explanatory value of conventional PCL-M and PHQ-9 total scores were compared to the four factor scores, the four factors explained 2% to 10% more total variance on measures of healthcare utilization and CAGE, CD-RISC, TCQ,
J. Tsai et al. / Journal of Affective Disorders 135 (2011) 310–314
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ence more severe, comorbid difficulties and have a greater need for mental healthcare services. The factor structure found in this study suggests the presence of more refined non-specific factor dimensions than a simple distinction between specific and non-specific symptoms of PTSD and depression. Specifically, the results differentiate between the hopelessness/depression factor from the detached/numbness symptom factor in showing that the former is uniquely related to more emergency room visits and the latter to more concurrent alcohol use. Separating feelings of being “distant or cut off” or “emotionally numb” (detached/numbness factor) from “feeling bad about yourself” or feeling “your future will somehow be cut short” (hopelessness/depression factor) may be helpful in identifying symptoms that confer greater risk for alcohol abuse and portend mental healthcare needs of treatmentseeking OEF/OIF/OND veterans. Of note, PTSD reexperiencing and avoidance symptoms loaded on the same factor, which has not been commonly observed in confirmatory factor analytic studies (Elhai et al., 2009; Palmieri et al., 2007; Pietrzak et al., 2010). Given that the sample was within one year of returning from deployment, this may be indicative of an early symptom presentation of PTSD characterized by less differentiated symptoms. While the bodily disturbance factor is not commonly observed in structural models of mood and anxiety disorders, it is consistent with emerging data suggesting a unique symptom cluster characterized by dysphoric arousal (Elhai et al., 2011). Results of this study are also consistent with recent literature highlighting the similarities between symptoms of mood and anxiety disorders, and recommendations to modify the current taxonomy of the Diagnostic Statistical Manual-IV (e.g., Gros et al., 2010; Resick and Miller, 2009; Rosen et al., 2008; Watson, 2005).
and PSSS scores (Table 2). Beta values of individual factors were also numerically larger than PCL-M and PHQ-9 total scores for many of the external measures assessed, most for any visit for psychiatric medications, CAGE scores, and CDRISC scores. 3. Discussion Results of this study are the first, to our knowledge, to examine the dimensionality of combat-related PTSD and depressive symptoms in treatment-seeking OEF/OIF/OND veterans. This study extends previous findings (Elhai et al., 2011; Gros et al., 2010; Resick and Miller, 2009; Rosen et al., 2008) in empirically demonstrating the overlap between symptoms of combat-related PTSD and depression as measured by two of the most commonly used instruments for these conditions. Certain non-specific symptoms of PTSD were found to be more closely aligned with symptoms of depression than other classic symptoms of PTSD. We found that PTSD and depressive symptoms may be categorized as four separate factors. Compared to conventional screening measures of PTSD and depression, these four factors explained more variance in measures of healthcare utilization, alcohol use, cognitive coping, resilience, and social support. Non-specific symptoms of PTSD, characterized by detachment/numbing, were most strongly associated with greater alcohol use, poorer cognitive coping strategies, less psychological resilience, and more psychotherapy visits than other PTSD and depressive symptoms. This finding, which corroborates previous research (Palmieri and Fitzgerald, 2005; Palmieri et al., 2007; Pietrzak et al., 2010), suggests that treatment-seeking OEF/OIF/OND veterans with symptoms characterized by emotional numbing/dysphoria may experi-
Table 2 Standardized beta values using four-factor solution as predictors of coping, resilience, and social support. Conventional measures
Any visit to primary care provider # of visits to primary care provider Any visit to emergency room # of visits to emergency room Any visit for psychotherapy # of visits for psychotherapy Any visit for psychiatric medication # of visits for psychiatric medication CAGE score Connor–Davidson Resilience Scale score Thought Control Questionnaire Reappraisal scale Worry scale Social Control scale Behavioral Distraction scale Self-Punishment scale Cognitive Distraction scale Postdeployment Social Support score ⁎ p b .05. ⁎⁎ p b .01. ⁎⁎⁎ p b .001
Alternative four-factor solution Factor 1: reexperiencing/ avoidance
Factor 2: detached/ numbness
Factor 3: hopelessness/ depression
Factor 4: bodily disturbance
Total R2
.02 .00 .06 .08 .23 .11 .13 .03 .06 .22
.14 −.06 .02 .18⁎ .54⁎
−.20 −.05 .27 .12 .72⁎⁎ .19⁎ .57⁎
−.20 .09 .38⁎ .23⁎
.06 .27⁎ −.32⁎⁎⁎
.13 .14 −.46⁎⁎⁎
−.20 −.13 −.05 .00 .34 .05 −.08 −.03 .03 −.01
.04 .03 .07 .10 .25 .13 .20 .04 .07 .32
.00 .21 .05 .04 .21 .03 .21
−.10 .27⁎⁎⁎ .21⁎
.05 .37⁎⁎⁎ .13 .05 .22⁎⁎ –.09 –.28⁎⁎⁎
−.05 .26⁎⁎⁎ .03 −.12 .38⁎⁎⁎ –.32⁎⁎⁎ –.26⁎⁎
−.13 .05 −.09 −.14 –.08 .09 –.08
.01 .26 .04 .03 .29 .10 .21
PCL-M total score
PHQ-9 total score
Total R
.20 .02 −.02 .09 .70⁎
−.39 −.08 .45 .21 .38 .16 .58 .12 .09 −.15 −.07 .21⁎ −.19 −.29⁎ .15 –.29⁎ –.31⁎⁎
.20 .17 .06 .20 −.36⁎⁎ −.04 .29⁎⁎ .36⁎⁎ .32⁎⁎ .34⁎⁎ .13 –.19
2
.16 .09 .12 .08 −.17⁎
.16 .33⁎⁎⁎ .03 –.28⁎⁎
.39 .24⁎⁎ .72⁎⁎
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This study is limited by a small sample size and employment of an exploratory factor analytic approach. Replication of these findings in larger samples of OEF/OIF/OND veterans is needed. An additional limitation is that healthcare use was assessed retrospectively and other measures were assessed concurrently with symptom measures. Consequently, the directionality of associations cannot be ascertained. Prospective studies on common mental health symptoms of OEF/OIF/ OND veterans and their relation to psychosocial outcomes is needed to better understand the utility of alternative conceptualizations of PTSD and depressive symptom structures in treatment-seeking veterans. Role of funding source Funding for this study was provided by the Clinical Neurosciences Division of the National Center for Posttraumatic Stress Disorder and a private donation. The work was supported by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development. The views presented here are those of the authors, alone, and do not represent the position of the United States Government. Conflict of interest None of the authors have any conflicts of interest on this study.
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depressive disorder and generalized anxiety disorder. Journal of Abnormal Psychology 117, 662–672. Gros, D.F., Simms, L.J., Acienro, R., 2010. Specificity of posttraumatic stress disorder symptoms: an investigation of comorbidity between posttraumatic stress disorder symptoms and depression in treatment-seeking veterans. The Journal of Nervous and Mental Disease 198, 885–890. Hoge, C.W., Auchterlonie, J.L., Milliken, C.S., 2006. Mental health problems, use of mental health services, and attrition from military services after returning from deployment to Iraq and Afghanistan. Journal of the American Medical Association 295, 1023–1032. King, L.A., King, D.W., Vogt, D.S., Knight, J.A., Samper, R.E., 2006. Deployment Risk and Resilience Inventory: a collection of measures for studying deployment-related experiences of military personnel and veterans. Military Psychology 18, 89–120. Kroenke, K., Spitzer, R.L., 2002. The PHQ-9: a new depression diagnostic and severity measure. Psychiatric Annals 32, 509–521. Nagelkerke, N.J.D., 1991. A note on a general definition of the coefficient of determination. Biometrika 78, 691–692. Palmieri, P.A., Fitzgerald, L.F., 2005. Confirmatory factor analysis of posttraumatic stress symptoms in sexually harassed women. Journal of Traumatic Stress 18, 657–666. Palmieri, P.A., Weathers, F.W., Difede, J., King, D.W., 2007. Confirmatory factor analysis of the PTSD Checklist and the Clinician-Administered PTSD Scale in disaster workers exposed to the World Trade Center Ground Zero. Journal of Abnormal Psychology 116, 329–341. Pietrzak, R.H., Goldstein, M.B., Malley, J.C., Rivers, A.J., Southwick, S.M., 2010. Structure of posttraumatic stress disorder symptoms and psychosocial functioning in Veterans of Operations Enduring Freedom and Iraqi Freedom. Psychiatry Research 178, 323–329. Resick, P.A., Miller, M.W., 2009. Post-traumatic stress disorder: anxiety or traumatic stress disorder? Journal of Traumatic Stress 22, 384–390. Rosen, G.M., Spitzer, R.L., McHugh, P.R., 2008. Problems with the posttraumatic stress disorder diagnosis and its future in DSM-V. The British Journal of Psychiatry 192, 3–4. Simms, L.J., Watson, D., 2002. Confirmatory factor analyses of post-traumatic stress symptoms in deployed and nondeployed veterans of the Gulf War. Journal of Abnormal Psychology 111, 637–647. Tanielian, T., Jaycox, L.H., 2008. Invisible wounds of war: psychological and cognitive injuries, their consequences, and services to assist recovery. The RAND Center for Military Health Policy Research, Santa Monica, CA. Vogt, D.S., Proctor, S.P., King, D.W., King, L.A., Vasterling, J.J., 2008. Validation of scales from the Deployment Risk and Resilience Inventory in a sample of Operation Iraqi Freedom veterans. Assessment 15, 391–403. Watson, D., 2005. Rethinking the mood and anxiety disorders: a quantitative hierarchical model for DSM-V. Journal of Abnormal Psychology 114, 522–536. Weathers, F.W., Huska, J., Keane, T., 1991. The PTSD Checklist—Military version (PCL-M). National Center for Posttraumatic Stress Disorder, Boston. Wells, A., Davies, M., 1994. The thought control questionnaire: a measure of individual differences in the control of unwanted thoughts. Behaviour Research and Therapy 32, 871–878. Wells, A., Reynolds, M., 1999. The Thought Control Questionnaire— psychometric properties in a clinical sample, and relationships with PTSD and depression. Psychological Medicine 29, 1089–1099.
Contents lists available at ScienceDirect
Journal of Affective Disorders j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / j a d
Preliminary communication
Examining the dimensionality of combat-related posttraumatic stress and depressive symptoms in treatment-seeking OEF/OIF/OND veterans☆ Jack Tsai a, b,⁎, Robert H. Pietrzak b, c, Steven M. Southwick b, c, Ilan Harpaz-Rotem b, c a b c
VA New England Mental Illness Research, Education, and Clinical Center, West Haven, CT, United States Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States National Center for Posttraumatic Stress Disorder, VA Connecticut Healthcare System, West Haven, CT, United States
a r t i c l e
i n f o
Article history: Received 10 June 2011 Accepted 29 June 2011 Available online 22 July 2011 Keywords: Posttraumatic stress disorder Major depressive disorder Substance abuse Coping
a b s t r a c t Background: This study examined the factor structure of two of the most commonly used screening measures of posttraumatic stress disorder and depression in 164 treatment-seeking veterans who served in Operations Enduring Freedom/Iraqi Freedom/New Dawn (OEF/OIF/ OND). Methods: Exploratory factor analysis was used to assess the dimensionality of items from the Posttraumatic Stress Disorder Checklist–Military Version (PCL-M) and the Patient Health Questionnaire-9 (PHQ-9). Regression analyses were then conducted to examine associations between factor scores of the resulting factor solution and measures of alcohol use, cognitive coping, psychological resilience, social support, and healthcare utilization. Results: A four-factor solution was found that consisted of clusters of symptoms reflecting reexperiencing/avoidance, detachment/numbing, hopelessness/depression, and bodily disturbance. Scores on the detachment/numbing factor were uniquely related to alcohol use, whereas scores on the hopelessness/depression factor was uniquely associated with emergency room visits. Compared to conventional PCL-M and PHQ-9 total scores, the fourfactor solution explained 2 to 10% more variance in scores on measures of alcohol use, cognitive coping, psychological resilience, social support, and healthcare utilization. Limitations: This study was limited by a small sample size and cross-sectional design. Conclusions: Combat-related posttraumatic stress disorder and depressive symptoms in treatment-seeking OEF/OIF/OND veterans may be better conceptualized by four dimensions of reexperiencing/avoidance, detachment/numbing, hopelessness/depression, and bodily disturbance symptoms. This symptom structure may provide greater utility when examining other outcomes of interest in this population. Published by Elsevier B.V.
Symptoms of posttraumatic stress disorder (PTSD) and depression are among the most common mental health complaints of military personnel who have served in Operation Enduring Freedom/Operation Iraqi Freedom/Operation New
☆ Funding for this study was provided by the Clinical Neurosciences Division of the National Center for Posttraumatic Stress Disorder, and a private donation. ⁎ Corresponding author at: VACT, 950 Campbell Ave., 151D, West Haven, CT 06516, United States. Tel.: + 1 203 932 5711x2090. E-mail address: [email protected] (J. Tsai). 0165-0327/$ – see front matter. Published by Elsevier B.V. doi:10.1016/j.jad.2011.06.057
Dawn (OEF/OIF/OND) (Cassels, 2010; Hoge et al., 2006; Tanielian and Jaycox, 2008). Two of the most commonly used screening instruments for PTSD and depression in this population are the PTSD Checklist–Military version (PCL-M; Weathers et al., 1991) and the Patient Health Questionnaire-9 (PHQ-9; Kroenke and Spitzer, 2002), respectively. While these instruments are often interpreted independently, a growing number of studies have found considerable overlap between symptoms of PTSD and depression (Gros et al., 2010; Resick and Miller, 2009; Rosen et al., 2008; Watson, 2005). This has led some researchers to question the utility of
J. Tsai et al. / Journal of Affective Disorders 135 (2011) 310–314
the current diagnostic classification system and measures based on this system in assessing psychopathology. For example, a recent exploratory factor analytic study of PTSD and major depression in treatment-seeking veterans found that non-specific symptoms of PTSD, referred to as dysphoria or emotional numbing symptoms, were more strongly correlated with symptoms of depression than specific symptoms of PTSD, such as reexperiencing and avoidance symptoms (Gros et al., 2010). Similar findings have been observed in samples of Gulf War veterans, Canadian military veterans, and vehicular accident survivors (Elhai et al., 2011; Grant et al., 2008; Simms and Watson, 2002). Taken together, these findings underscore the importance of examining alternative conceptualizations of how PTSD and depression symptoms may manifest in clinical samples. To date, little research has examined how specific and non-specific symptoms of PTSD and depression may be differentially related to other variables of interest. Given that dysphoria/emotional numbing symptoms of PTSD involve a loss of interest in activities, detachment from others, and restricted range of affect (Feeny et al., 2000), these symptoms may be particularly strongly related to psychosocial functioning. Indeed, available data suggests that, relative to reexperiencing and avoidance symptoms, dysphoria/ emotional numbing symptoms of PTSD are more strongly associated with concomitant psychiatric symptoms, alcohol use problems, greater perceived stigma, decreased psychological resilience, lower life satisfaction, as well as greater mental healthcare utilization (Palmieri and Fitzgerald, 2005; Palmieri et al., 2007; Pietrzak et al., 2010). The current study aimed to extend previous research by exploring (1) the factor structure of two of the most commonly used screening measures of PTSD and depression in a sample of treatment-seeking OEF/OIF/OND veterans; and (2) examining how the resulting factor solution relates to psychosocial measures previously linked to non-specific symptoms of PTSD (i.e., alcohol use, cognitive coping, psychological resilience, social support, and healthcare utilization; Palmieri and Fitzgerald, 2005; Palmieri et al., 2007; Pietrzak et al., 2010). We hypothesized that an exploratory factor analysis would yield a factor solution characterized by both specific and non-specific symptoms of PTSD; and that non-specific symptoms (i.e., dysphoria/ numbing) would be uniquely associated with poorer psychosocial status and greater mental healthcare utilization compared to other PTSD and depression symptoms. 1. Measures 1.1. PTSD and depression Combat-related PTSD symptoms were assessed with the PTSD Checklist-Military version (PCL-M; Weathers et al., 1991). The PCL-M is a 17-item screening instrument based on DSM-IV criteria for PTSD. In this study, there was excellent internal consistency with Cronbach's alpha = .92. Depressive symptoms were assessed with the Patient Health Questionnaire-9 (PHQ-9; Kroenke and Spitzer, 2002). The PHQ-9 is a 9-item self-report screening instrument for depression. In this study, there was good internal consistency with alpha = .89.
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1.2. External measures Alcohol use was assessed with a 4-item instrument called the CAGE questionnaire (Ewing, 1984). The CAGE is used to identify possible alcohol problems and has been used in hundreds of studies. This study found adequate internal consistency on this measure, with alpha = .70. Psychological resilience was assessed using the 25-item Connor–Davidson Resilience Scale (CD-RISC; Connor and Davidson, 2003). Excellent internal consistency was found for the total scale, alpha = .95. Cognitive coping was assessed with the Thought Control Questionnaire (TCQ; Wells and Davies, 1994; Wells and Reynolds, 1999). The TCQ is a 30-item measure that assesses the frequency of the use of thought control strategies on six separate scales: worry, self-punishment, reappraisal, behavioral distraction, cognitive distraction, and social control. In this study, there was adequate internal consistency for each of the scales with alpha = .78, .83, .55, .65, .75, and .58, respectively. Postdeployment Social Support Scale (PSSS) is a 15-item measure from the Deployment Risk and Resilience Inventory (King et al., 2006; Vogt et al., 2008) that assesses support after military deployment. In this study, there was good internal consistency with alpha = .86. Healthcare utilization was assessed with four questions that asked participants how many visits they made in the past six months to a primary care provider, to an emergency room, to a mental health professional for counseling, and to a mental health professional for medication. All measures were administered after participants gave informed consent and procedures were approved by the local institutional review board. 1.3. Data analysis To examine potential overlap between items on the PHQ-9 and PCL-M, a principal components factor analysis was conducted that specified a priori two factors on the 26 items from the PHQ-9 and the PCL-M. Both orthogonal (varimax) and oblique (promax) rotations were examined. An exploratory principal components factor analysis was then conducted with both varimax and promax rotations. Pearson correlations, using an adjusted significance level of p b .01 to control for Type I error, were computed between factor scores and measures of healthcare utilization, coping, alcohol use, resilience, and social support. Two series of regression analyses were then conducted; the first used conventional PHQ-9 and PCL-M total scores as independent variables, the second used factor scores from the exploratory factor analysis as independent variables. Multiple regression was used for continuous dependent variables and logistic regression was used for dichotomous measures of healthcare use. Adjusted total R 2 was calculated in multiple regression and Nagelkerke (1991) total R 2 in logistic regression analyses. 2. Results A factor analysis with a varimax rotation specifying two factors on items from the PHQ-9 and the PCL-M accounted for 56.84% of the total variance. Most items loaded highest on
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Table 1 Exploratory factor analysis of items from the Patient Health Questionnaire-9 (PHQ-9) and the Posttraumatic Stress Disorder Checklist—Military version (PCL-M). Items
Factor 1: Factor 2: Factor 3: Factor 4: reexperiencing/avoidance detached/numbness hopelessness/depression bodily disturbance
Having physical reactions when something reminded you of a SME (PCL-M) Suddenly acting or feelings as if the SME was happening again (PCL-M) Avoiding thinking about or talking about or having feelings related to a SME (PCL-M) Feeling very upset when something reminded you of a SME (PCL-M) Repeated, disturbing memories, thoughts, or images of a SMEa (PCL-M) Repeated, disturbing dreams of a SME (PCL-M) Avoiding activities or situations because they reminded you of a SME (PCL-M) Feeling jumpy or easily startled (PCL-M) Being “super-alert” or watchful or on guard (PCL-M) Trouble remembering important parts of a SME (PCL-M) Feeling distant or cut off from other people (PCL-M) Loss of interest in activities you used to enjoy (PCL-M) Feeling emotionally numb or unable to have loving feelings (PCL-M) Little interest or pleasure in doing things (PHQ9) Feeling irritable or having angry outbursts (PCL-M) Having difficulty concentrating (PCL-M) Thoughts you would be better off dead or hurting yourself (PHQ9) Feeling bad about yourself (PHQ9) Trouble concentrating on things (PHQ9) Moving or speaking slowly or being fidgety or restless (PHQ9) Feeling down, depressed, or hopeless (PHQ9) Feeling as if your future will somehow be cut short (PCL-M) Trouble falling or staying asleep, or sleeping too much (PHQ9) Trouble falling or staying asleep (PCL-M) Poor appetite or overeating (PHQ9) Feeling tired or having little energy (PHQ9)
.79
.14
.20
.17
.77
.19
.22
.11
.77
.33
.06
.04
.75
.42
.16
.16
.75
.01
.21
.35
.74 .74
.05 .31
.17 .25
.39 −.01
.61 .55 .49 .24 .24 .29
.48 .48 .27 .77 .74 .72
.08 −.08 .40 .28 .31 .33
.22 .29 −.08 .18 .08 .15
.08 .36 .34 .11
.69 .65 .61 .13
.38 .14 .30 .72
.28 .22 .19 .03
.25 .17 .22
.29 .21 .37
.70 .61 .58
.13 .33 .20
.10 .40
.54 .47
.56 .51
.32 .03
.20
.19
.14
.86
.39 .08 .14
.25 .21 .41
.05 .48 .41
.75 .59 .52
a
SME = Stressful Military Experience.
their parent scale. However, items 9 (“Loss of interest in activities you used to enjoy”), 10 (“Feeling distant or cut off from other people”), 11 (“Feeling emotionally numb or unable to having loving feelings”), 12 (“Feeling as if your future will somehow be cut short”), 14 (“feeling irritable or having angry outbursts”), and 15 (“having difficulty concentrating”) from the PCL-M had higher loadings on the PHQ-9 factor. None of the PHQ-9 scale items had higher loadings on the PCL-M factor. A promax rotation yielded similar results. An exploratory factor analysis with a varimax rotation of items from the PHQ-9 and the PCL-M revealed four factors with eigenvalues over 1.0, which were labeled Factor 1: Reexperiencing/Avoidance, Factor 2: Detached/Numbness, Factor 3: Hopelessness/Depression, and Factor 4: Bodily Disturbance (Table 1). These four factors accounted for 67.23% of the total variance. A factor analysis with a promax rotation yielded similar results, except that item 16 on the PCL-M (“being ‘super-alert’ or watchful or on guard”) had a slightly higher loading on the 2nd factor instead of the 1st factor (loading = .48 and .43) and item 2 of the PHQ-9 (“feeling down, depressed, or hopeless”) had a slightly higher loading on the 2nd factor than the 3 rd factor (loading = .49 and .43).
Correlations between orthogonal factor scores and measures of healthcare use, coping, alcohol use, resilience, and social support showed that Factor 1: Reexperiencing/Avoidance was significantly and solely associated with higher TCQ: Social Control scores (r = .27, p b .01). Factor 2: Detached/ Numbness was significantly and solely associated with higher scores on the CAGE (r = .26, p b .01). Factor 3: Hopelessness/ Depression was significantly and solely associated with a greater number of emergency room visits (r = .23, p b .01), psychotherapy visits (r = .25, p b .01), and lower TCQ: Cognitive Distraction scores (r = −.32, p b .001). Factor 2: Detached/Numbness (r = −.31, p b .01) and Factor 3: Hopelessness/Depression (r = −.46, p b .01) were both associated with lower scores on the CD-RISC score. All factors, except Factor 4: Bodily Reaction, were significantly correlated with higher scores on TCQ: Worry (r = .27, .37, and .26, respectively, all p b .01) and TCQ: Punishment (r = .32, .22, .39, p b .01), and lower scores on the PSSS score (r = −.28, −.28, −.25, p b .01). When the explanatory value of conventional PCL-M and PHQ-9 total scores were compared to the four factor scores, the four factors explained 2% to 10% more total variance on measures of healthcare utilization and CAGE, CD-RISC, TCQ,
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ence more severe, comorbid difficulties and have a greater need for mental healthcare services. The factor structure found in this study suggests the presence of more refined non-specific factor dimensions than a simple distinction between specific and non-specific symptoms of PTSD and depression. Specifically, the results differentiate between the hopelessness/depression factor from the detached/numbness symptom factor in showing that the former is uniquely related to more emergency room visits and the latter to more concurrent alcohol use. Separating feelings of being “distant or cut off” or “emotionally numb” (detached/numbness factor) from “feeling bad about yourself” or feeling “your future will somehow be cut short” (hopelessness/depression factor) may be helpful in identifying symptoms that confer greater risk for alcohol abuse and portend mental healthcare needs of treatmentseeking OEF/OIF/OND veterans. Of note, PTSD reexperiencing and avoidance symptoms loaded on the same factor, which has not been commonly observed in confirmatory factor analytic studies (Elhai et al., 2009; Palmieri et al., 2007; Pietrzak et al., 2010). Given that the sample was within one year of returning from deployment, this may be indicative of an early symptom presentation of PTSD characterized by less differentiated symptoms. While the bodily disturbance factor is not commonly observed in structural models of mood and anxiety disorders, it is consistent with emerging data suggesting a unique symptom cluster characterized by dysphoric arousal (Elhai et al., 2011). Results of this study are also consistent with recent literature highlighting the similarities between symptoms of mood and anxiety disorders, and recommendations to modify the current taxonomy of the Diagnostic Statistical Manual-IV (e.g., Gros et al., 2010; Resick and Miller, 2009; Rosen et al., 2008; Watson, 2005).
and PSSS scores (Table 2). Beta values of individual factors were also numerically larger than PCL-M and PHQ-9 total scores for many of the external measures assessed, most for any visit for psychiatric medications, CAGE scores, and CDRISC scores. 3. Discussion Results of this study are the first, to our knowledge, to examine the dimensionality of combat-related PTSD and depressive symptoms in treatment-seeking OEF/OIF/OND veterans. This study extends previous findings (Elhai et al., 2011; Gros et al., 2010; Resick and Miller, 2009; Rosen et al., 2008) in empirically demonstrating the overlap between symptoms of combat-related PTSD and depression as measured by two of the most commonly used instruments for these conditions. Certain non-specific symptoms of PTSD were found to be more closely aligned with symptoms of depression than other classic symptoms of PTSD. We found that PTSD and depressive symptoms may be categorized as four separate factors. Compared to conventional screening measures of PTSD and depression, these four factors explained more variance in measures of healthcare utilization, alcohol use, cognitive coping, resilience, and social support. Non-specific symptoms of PTSD, characterized by detachment/numbing, were most strongly associated with greater alcohol use, poorer cognitive coping strategies, less psychological resilience, and more psychotherapy visits than other PTSD and depressive symptoms. This finding, which corroborates previous research (Palmieri and Fitzgerald, 2005; Palmieri et al., 2007; Pietrzak et al., 2010), suggests that treatment-seeking OEF/OIF/OND veterans with symptoms characterized by emotional numbing/dysphoria may experi-
Table 2 Standardized beta values using four-factor solution as predictors of coping, resilience, and social support. Conventional measures
Any visit to primary care provider # of visits to primary care provider Any visit to emergency room # of visits to emergency room Any visit for psychotherapy # of visits for psychotherapy Any visit for psychiatric medication # of visits for psychiatric medication CAGE score Connor–Davidson Resilience Scale score Thought Control Questionnaire Reappraisal scale Worry scale Social Control scale Behavioral Distraction scale Self-Punishment scale Cognitive Distraction scale Postdeployment Social Support score ⁎ p b .05. ⁎⁎ p b .01. ⁎⁎⁎ p b .001
Alternative four-factor solution Factor 1: reexperiencing/ avoidance
Factor 2: detached/ numbness
Factor 3: hopelessness/ depression
Factor 4: bodily disturbance
Total R2
.02 .00 .06 .08 .23 .11 .13 .03 .06 .22
.14 −.06 .02 .18⁎ .54⁎
−.20 −.05 .27 .12 .72⁎⁎ .19⁎ .57⁎
−.20 .09 .38⁎ .23⁎
.06 .27⁎ −.32⁎⁎⁎
.13 .14 −.46⁎⁎⁎
−.20 −.13 −.05 .00 .34 .05 −.08 −.03 .03 −.01
.04 .03 .07 .10 .25 .13 .20 .04 .07 .32
.00 .21 .05 .04 .21 .03 .21
−.10 .27⁎⁎⁎ .21⁎
.05 .37⁎⁎⁎ .13 .05 .22⁎⁎ –.09 –.28⁎⁎⁎
−.05 .26⁎⁎⁎ .03 −.12 .38⁎⁎⁎ –.32⁎⁎⁎ –.26⁎⁎
−.13 .05 −.09 −.14 –.08 .09 –.08
.01 .26 .04 .03 .29 .10 .21
PCL-M total score
PHQ-9 total score
Total R
.20 .02 −.02 .09 .70⁎
−.39 −.08 .45 .21 .38 .16 .58 .12 .09 −.15 −.07 .21⁎ −.19 −.29⁎ .15 –.29⁎ –.31⁎⁎
.20 .17 .06 .20 −.36⁎⁎ −.04 .29⁎⁎ .36⁎⁎ .32⁎⁎ .34⁎⁎ .13 –.19
2
.16 .09 .12 .08 −.17⁎
.16 .33⁎⁎⁎ .03 –.28⁎⁎
.39 .24⁎⁎ .72⁎⁎
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This study is limited by a small sample size and employment of an exploratory factor analytic approach. Replication of these findings in larger samples of OEF/OIF/OND veterans is needed. An additional limitation is that healthcare use was assessed retrospectively and other measures were assessed concurrently with symptom measures. Consequently, the directionality of associations cannot be ascertained. Prospective studies on common mental health symptoms of OEF/OIF/ OND veterans and their relation to psychosocial outcomes is needed to better understand the utility of alternative conceptualizations of PTSD and depressive symptom structures in treatment-seeking veterans. Role of funding source Funding for this study was provided by the Clinical Neurosciences Division of the National Center for Posttraumatic Stress Disorder and a private donation. The work was supported by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development. The views presented here are those of the authors, alone, and do not represent the position of the United States Government. Conflict of interest None of the authors have any conflicts of interest on this study.
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