Edited by: Cesar Merino-Soto, Universidad de San Martín de Porres, Peru
Reviewed by: Antonia Cascales-Martinez, University of Murcia, Spain; Wolfgang Rauch, Ludwigsburg University, Germany
This article was submitted to Quantitative Psychology and Measurement, a section of the journal Frontiers in Psychology
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While the factor structure of post-traumatic stress disorder (PTSD) symptoms has been investigated among various traumatized populations in Western and high-income countries, knowledge regarding the validity of factor structure of PTSD among culturally diverse populations in low-and-middle-income countries is limited. The current study examined the factor structure and cultural invariance of PTSD in 521 Iraqi and 993 Syrian war-affected displaced people who were living in the Kurdistan Region of Iraq. Results from confirmatory factor analyses demonstrated that alternative factor models for PTSD, including a new model derived from this population (anhedonia and affect model) resulted in a better fit than the current DSM V models. Taken together, the results showed that a good fit, as well as the measurement invariance of PTSD factors, could be obtained by applying the anhedonia and hybrid model. This study provides further support for the anhedonia and hybrid model of PTSD and fills an important gap in knowledge about the validity of PTSD symptom clusters among Arab and Kurdish populations.
Post-traumatic stress disorder (PTSD) is a common psychological disorder worldwide (Atwoli et al.,
Prominent examples of war-affected societies include the Middle East regions affected by the wars in Syria and Iraq. Since the Arab Spring movement brought social and political instability to this region in 2011, this area has been considered as one of the top global hotspots for insurgencies and war. The ongoing civil wars in Syria and Iraq have resulted in one of the largest migration waves in modern history. According to the United Nations High Commissioner for Refugees (UNHCR), from the start of the Arab Spring events in early 2011 until the end of 2017, more than three million Iraqi people and nearly half of Syria's population have been displaced (United Nations High Commissioner for Refugees,
Post-traumatic stress disorder is a psychological disorder characterized by a set of symptom clusters that could occur following the witnessing or experiencing of a traumatic event. Although it has been a matter of some debate since its introduction into the Diagnostic and Statistical Manual of Mental Disorders (DSM-III; American Psychiatric Association,
The first major changes of symptom clusters were introduced in the current version of the DSM (DSM-V; American Psychiatric Association,
However, since the introduction of PTSD as a disorder, empirical tests of the defined PTSD clusters have found only limited validity of the criteria. On the basis of factor analyses, several alternative models for PTSD symptom clusters have been proposed. King et al. (
After the introduction of the DSM V, the dysphoric arousal model inspired other researchers to propose and test several alternative models for PTSD symptom clusters. In the first large-scale factor analysis that was carried out outside of the United States, Liu et al. (
To date, the four-factor model of the DSM V criteria for PTSD has been studied among different traumatized populations, including survivors of natural disasters (Liu et al.,
The study sample was drawn from a collaborative research project between Bielefeld University in Germany and Koya University in the KRI. A survey was carried out between December 2016 and July 2017, where 26 locally trained clinical psychologists and social workers interviewed unselected 521 Iraqi IDPs and 993 Syrian refugees. Using standardized written informed consent sheet, participants were fully informed about the procedures of the study. Due to cultural considerations (Ibrahim and Hassan,
Due to the absence of reliable census data from the displaced camps, a random selection of individuals and households was not possible, therefore we used a pragmatic sampling approach based on a random selection of individuals and households. The camps were subdivided into 6–7 sections by the camp administrations, and tents were chosen based on a random selection of households by spinning a pen from the zone center. Trained interviewers visited the household that was in a straight line from the tip of the pen, identified the people in the household and determined their eligibility for participation in the study. The details of ethical considerations, as well as the data collection procedure and sample selection, are described elsewhere (Ibrahim et al.,
The majority of the participants were female (63%). About one third (31%) of the participants were illiterate, and 87.1% of them had no regular monthly income, others had between 30,000 and 1,200,000 IDQ (1,000 IDQ ≈ 0.65 Euro local rate). Due to the variety of official languages in the northern regions of Syria and Iraq, participants were free to choose between either Kurdish and Arabic languages during their interview. As a result, 55.5% of the full sample (12.3% of Iraqis and 78.2% of Syrian) were interviewed in Kurdish and the rest were interviewed in Arabic (see
Sociodemographic information.
Male | 548 (36.2) |
Female | 966 (63.8) |
Muslim | 1,060 (70) |
Yazidi | 454 (30) |
Kurd | 1,160 (76.6) |
Arab | 354 (23.4) |
Iraqi | 521 (34.4) |
Syrian | 993 (65.6) |
5.83 (25.92) | |
Currently working | 407 (26.9) |
Currently non-working | 1,107 (73.1) |
Kurdish | 841 (55.5) |
Arabic | 673 (44.5) |
No | 1,304 (86.1) |
Yes | 210 (13.9) |
17,045.90 (91,753.87) | |
3.49 (2.76) | |
Number of boys |
1.80 (1.65) |
Number of girls |
1.68 (1.67) |
Kurdish and Arabic translations of the PCL-5 that had been validated in the cultural context previously (Ibrahim et al.,
Kurdish and Arabic versions of the DHSCL-25 (Ibrahim et al.,
Based on focus group discussions with displaced Iraqi and Syrian people and including items from different sources [e.g., War Exposure Scale (Ibrahim et al.,
The normal distribution of the PCL-5 sum-score, as well as the subscale scores in each single factor in all different models were checked by examining the indicators of skewness and kurtosis along with a visual inspection of the corresponding histograms, normal Q–Q plots, and boxplots. Results showed that all scales were normally distributed. To investigate the underlying dimensions of the PCL-5, an exploratory factor analysis was performed using a maximum likelihood approach with an oblique rotation method. The number of factors was determined based on eigenvalues >1 and scree plot.
To verify the factor structure of each PTSD model, a set of confirmatory factor analyses (CFA) was carried out. Model fit was evaluated on the basis of various fit indices. Since the chi-square test is extremely sensitive to sample size, this test was considered inadequate for the large sample size of this study (Bentler and Bonett,
The measurement invariance was investigated by testing the invariance of the presumed underlying constructs of the PCL-5 across the sample subgroups, divided by nationality (Iraqi and Syrian), language of the interview (Kurdish and Arabic), and ethnicity (Kurd and Arab). For this purpose, sequential steps of the CFA with single-groups as well as across groups were conducted (Steenkamp and Baumgartner,
All descriptive statistics were carried out using the Statistical Package for Social Sciences (SPSS-Windows version 25). The relationship between continuous variables was examined using Pearson's correlation coefficient. A
Results from descriptive statistics showed that participants had been exposed to between 0 and 20 traumatic event types in their lifetime (
A maximum likelihood exploratory factor analysis with oblique rotation method was conducted first. Results from a Kaiser-Meyer-Olkin (KMO) test of sampling adequacy and Bartlett's test of sphericity showed that the data meets the factorability criteria (KMO = 0.938 and Bartlett's test [
Factor loading matrix of PCL-5 for each factor.
2 | Repeated, disturbing dreams of the stressful experience? | 0.794 | 0.140 | −0.148 | −0.120 |
1 | Repeated, disturbing, and unwanted memories of the stressful experience? | 0.753 | −0.139 | 0.071 | 0.045 |
4 | Feeling very upset when something reminded you of the stressful experience? | 0.749 | −0.173 | 0.111 | 0.079 |
5 | Having strong physical reactions when something reminded you of the stressful experience? | 0.667 | 0.032 | 0.071 | 0.035 |
3 | Suddenly feeling or acting as if the stressful experience were actually happening again? | 0.479 | 0.181 | 0.059 | 0.056 |
11 | Having strong negative feelings, such as fear, horror, anger, guilt, or shame? | 0.365 | 0.170 | 0.148 | 0.030 |
16 | Taking too many risks or doing things that could cause you harm? | −0.196 | 0.676 | 0.110 | 0.008 |
17 | Being “super alert” or watchful or on guard? | 0.163 | 0.611 | −0.111 | 0.060 |
18 | Feeling jumpy or easily startled? | 0.380 | 0.549 | −0.162 | −0.056 |
8 | Trouble remembering important parts of the stressful experience? | −0.051 | 0.480 | −0.030 | 0.123 |
19 | Having difficulty concentrating? | 0.026 | 0.480 | 0.200 | −0.024 |
20 | Trouble falling or staying asleep? | 0.140 | 0.458 | 0.138 | −0.057 |
10 | Blaming yourself or someone else for the stressful experience or what happened after it? | 0.021 | 0.432 | 0.134 | 0.054 |
15 | Irritable behavior, angry outbursts, or acting aggressively? | 0.189 | 0.403 | 0.158 | −0.083 |
9 | Having strong negative beliefs about yourself, other people, or the world? | −0.042 | 0.362 | 0.251 | 0.104 |
14 | Trouble experiencing positive feelings? | 0.051 | 0.017 | 0.757 | −0.021 |
12 | Loss of interest in activities that you used to enjoy? | 0.157 | −0.026 | 0.657 | 0.006 |
13 | Feeling distant or cut off from other people? | −0.075 | 0.168 | 0.568 | −0.051 |
6 | Avoiding memories, thoughts, or feelings related to the stressful experience? | 0.037 | 0.031 | −0.032 | 0.882 |
7 | Avoiding external reminders of the stressful experience? | −0.013 | 0.054 | −0.015 | 0.880 |
As shown in
Item distribution of PTSD symptoms based on seven PTSD models.
1. Repeated, disturbing, and unwanted memories of the stressful experience? | IN | IN | IN | IN | IN | IN | IN |
2. Repeated, disturbing dreams of the stressful experience? | IN | IN | IN | IN | IN | IN | IN |
3. Suddenly feeling or acting as if the stressful experience were actually happening again? | IN | IN | IN | IN | IN | IN | IN |
4. Feeling very upset when something reminded you of the stressful experience? | IN | IN | IN | IN | IN | IN | IN |
5. Having strong physical reactions when something reminded you of the stressful experience? | IN | IN | IN | IN | IN | IN | IN |
6. Avoiding memories, thoughts, or feelings related to the stressful experience? | AV | AV | AV | AV | AV | AV | AV |
7. Avoiding external reminders of the stressful experience? | AV | AV | AV | AV | AV | AV | AV |
8. Trouble remembering important parts of the stressful experience? | NACM | NCBA | DY | NACM | NACM | NA | NA |
9. Having strong negative beliefs about yourself, other people, or the world? | NACM | NCBA | DY | NACM | NACM | NA | NA |
10. Blaming yourself or someone else for the stressful experience or what happened after it? | NACM | NCBA | DY | NACM | NACM | NA | NA |
11. Having strong negative feelings, such as fear, horror, anger, guilt, or shame? | NACM | NCBA | DY | NACM | NACM | NA | NA |
12. Loss of interest in activities that you used to enjoy? | NACM | AN | DY | NACM | NACM | AN | AN |
13. Feeling distant or cut off from other people? | NACM | AN | DY | NACM | NACM | AN | AN |
14. Trouble experiencing positive feelings? | NACM | AN | DY | NACM | NACM | AN | AN |
15. Irritable behavior, angry outbursts, or acting aggressively? | AAR | NCBA | DY | DYA | EB | DYA | EB |
16. Taking too many risks or doing things that could cause you harm? | AAR | NCBA | AAR | DYA | EB | DYA | EB |
17. Being “super alert” or watchful or on guard? | AAR | NCBA | AAR | AA | AA | AA | AA |
18. Feeling jumpy or easily startled? | AAR | NCBA | AAR | AA | AA | AA | AA |
19. Having difficulty concentrating? | AAR | NCBA | DY | DYA | DYA | DYA | DYA |
20. Trouble falling or staying asleep? | AAR | NCBA | DY | DYA | DYA | DYA | DYA |
Reliability estimates of the PTSD dimensions in different models.
DSM 5 | IN | 0.848 | [0.835, 0.859] | 0.809 | [0.782, 0.834] | 0.810 | [0.790, 0.828] | 0.814 | [0.793, 0.833] | 0.841 | [0.821, 0.859] | 0.828 | [0.811, 0.843] | 0.841 | [0.821, 0.859] |
AV | 0.892 | [0.880, 0.902] | 0.896 | [0.877, 0.913] | 0.881 | [0.865, 0.895] | 0.858 | [0.838, 0.876] | 0.923 | [0.910, 0.934] | 0.888 | [0.875, 0.901] | 0.923 | [0.910, 0.934] | |
NACM | 0.797 | [0.781, 0.812] | 0.784 | [0.755, 0.811] | 0.761 | [0.738, 0.783] | 0.777 | [0.753, 0.799] | 0.785 | [0.759, 0.809] | 0.787 | [0.768, 0.806] | 0.785 | [0.759, 0.809] | |
AAR | 0.813 | [0.799, 0.828] | 0.784 | [0.754, 0.812] | 0.742 | [0.716, 0.766] | 0.756 | [0.729, 0.780] | 0.809 | [0.789, 0.831] | 0.782 | [0.762, 0.801] | 0.809 | [0.786, 0.831] | |
Anhedonia and affect | IN | 0.848 | [0.835, 0.859] | 0.809 | [0.782, 0.834] | 0.810 | [0.790, 0.828] | 0.814 | [0.793, 0.833] | 0.841 | [0.821, 0.859] | 0.828 | [0.811, 0.843] | 0.841 | [0.821, 0.859] |
AV | 0.892 | [0.880, 0.902] | 0.896 | [0.877, 0.913] | 0.881 | [0.865, 0.895] | 0.858 | [0.838, 0.876] | 0.923 | [0.910, 0.934] | 0.888 | [0.875, 0.901] | 0.923 | [0.910, 0.934] | |
NCBA | 0.854 | [0.843, 0.865] | 0.816 | [0.791, 0.839] | 0.760 | [0.737, 0.782] | 0.804 | [0.784, 0.823] | 0.853 | [0.836, 0.869] | 0.828 | [0.813, 0.843] | 0.825 | [0.796, 0.851] | |
AN | 0.762 | [0.740, 0.782] | 0.725 | [0.681, 0.763] | 0.769 | [0.742, 0.792] | 0.786 | [0.759, 0.810] | 0.714 | [0.674, 0.749] | 0.764 | [0.740, 0.787] | 0.724 | [0.670, 0.771] | |
Dysphoria | IN | 0.848 | [0.835, 0.859] | 0.809 | [0.782, 0.834] | 0.810 | [0.790, 0.828] | 0.814 | [0.793, 0.833] | 0.841 | [0.821, 0.859] | 0.828 | [0.811, 0.843] | 0.841 | [0.821, 0.859] |
AV | 0.892 | [0.880, 0.902] | 0.896 | [0.877, 0.913] | 0.881 | [0.865, 0.895] | 0.858 | [0.838, 0.876] | 0.923 | [0.910, 0.934] | 0.888 | [0.875, 0.901] | 0.923 | [0.910, 0.934] | |
DY | 0.862 | [0.851, 0.872] | 0.849 | [0.829, 0.868] | 0.830 | [0.814, 0.845] | 0.838 | [0.822, 0.854] | 0.857 | [0.840, 0.872] | 0.847 | [0.833, 0.860] | 0.844 | [0.818, 0.867] | |
AAR | 0.733 | [0.704, 0.758] | 0.666 | [0.603, 0.718] | 0.623 | [0.573, 0.667] | 0.663 | [0.579, 0.679] | 0.729 | [0.685, 0.767] | 0.712 | [0.677, 0.743] | 0.613 | [0.524, 0.686] | |
Dysphoric arousal | IN | 0.848 | [0.835, 0.859] | 0.809 | [0.782, 0.834] | 0.810 | [0.790, 0.828] | 0.814 | [0.793, 0.833] | 0.841 | [0.821, 0.859] | 0.828 | [0.811, 0.843] | 0.841 | [0.821, 0.859] |
AV | 0.892 | [0.880, 0.902] | 0.896 | [0.877, 0.913] | 0.881 | [0.865, 0.895] | 0.858 | [0.838, 0.876] | 0.923 | [0.910, 0.934] | 0.888 | [0.875, 0.901] | 0.923 | [0.910, 0.934] | |
NACM | 0.797 | [0.781, 0.812] | 0.784 | [0.755, 0.811] | 0.761 | [0.738, 0.783] | 0.777 | [0.753, 0.799] | 0.785 | [0.759, 0.809] | 0.787 | [0.768, 0.806] | 0.785 | [0.759, 0.809] | |
DYA | 0.735 | [0.713, 0.756] | 0.715 | [0.673, 0.753] | 0.669 | [0.634, 0.701] | 0.686 | [0.649, 0.719] | 0.730 | [0.695, 0.762] | 0.701 | [0.672, 0.728] | 0.714 | [0.662, 0.760] | |
AA | 0.733 | [0.704, 0.758] | 0.666 | [0.603, 0.718] | 0.623 | [0.573, 0.667] | 0.663 | [0.579, 0.679] | 0.729 | [0.685, 0.767] | 0.712 | [0.677, 0.743] | 0.613 | [0.524, 0.686] | |
Externalizing behaviors | IN | 0.848 | [0.835, 0.859] | 0.809 | [0.782, 0.834] | 0.810 | [0.790, 0.828] | 0.814 | [0.793, 0.833] | 0.841 | [0.821, 0.859] | 0.828 | [0.811, 0.843] | 0.841 | [0.821, 0.859] |
AV | 0.892 | [0.880, 0.902] | 0.896 | [0.877, 0.913] | 0.881 | [0.865, 0.895] | 0.858 | [0.838, 0.876] | 0.923 | [0.910, 0.934] | 0.888 | [0.875, 0.901] | 0.923 | [0.910, 0.934] | |
NCBA | 0.854 | [0.843, 0.865] | 0.816 | [0.791, 0.839] | 0.760 | [0.737, 0.782] | 0.804 | [0.784, 0.823] | 0.853 | [0.836, 0.869] | 0.828 | [0.813, 0.843] | 0.825 | [0.796, 0.851] | |
EB | 0.578 | [0.534, 0.619] | 0.559 | [0.476, 0.629] | 0.495 | [0.428, 0.554] | 0.535 | [0.468, 0.594] | 0.556 | [0.484, 0.619] | 0.540 | [0.484, 0.590] | 0.553 | [0.449, 0.637] | |
AA | 0.733 | [0.704, 0.758] | 0.666 | [0.603, 0.718] | 0.623 | [0.573, 0.667] | 0.663 | [0.579, 0.679] | 0.729 | [0.685, 0.767] | 0.712 | [0.677, 0.743] | 0.613 | [0.524, 0.686] | |
DYA | 0.647 | [0.609, 0.681] | 0.624 | [0.553, 0.683] | 0.588 | [0.533, 0.636] | 0.589 | [0.530, 0.641] | 0.656 | [0.600, 0.705] | 0.618 | [0.571, 0.659] | 0.609 | [0.519, 0.683] | |
Anhedonia | IN | 0.848 | [0.835, 0.859] | 0.809 | [0.782, 0.834] | 0.810 | [0.790, 0.828] | 0.814 | [0.793, 0.833] | 0.841 | [0.821, 0.859] | 0.828 | [0.811, 0.843] | 0.841 | [0.821, 0.859] |
AV | 0.892 | [0.880, 0.902] | 0.896 | [0.877, 0.913] | 0.881 | [0.865, 0.895] | 0.858 | [0.838, 0.876] | 0.923 | [0.910, 0.934] | 0.888 | [0.875, 0.901] | 0.923 | [0.910, 0.934] | |
NA | 0.659 | [0.631, 0.687] | 0.662 | [0.612, 0.707] | 0.528 | [0.479, 0.574] | 0.573 | [0.523, 0.618] | 0.671 | [0.621, 0.709] | 0.604 | [0.565, 0.640] | 0.652 | [0.589, 0.708] | |
AN | 0.762 | [0.740, 0.782] | 0.725 | [0.681, 0.763] | 0.769 | [0.742, 0.792] | 0.786 | [0.759, 0.810] | 0.714 | [0.674, 0.749] | 0.764 | [0.740, 0.787] | 0.724 | [0.670, 0.771] | |
DYA | 0.647 | [0.609, 0.681] | 0.624 | [0.553, 0.683] | 0.588 | [0.533, 0.636] | 0.589 | [0.530, 0.641] | 0.656 | [0.600, 0.705] | 0.618 | [0.571, 0.659] | 0.609 | [0.519, 0.683] | |
AA | 0.733 | [0.704, 0.758] | 0.666 | [0.603, 0.718] | 0.623 | [0.573, 0.667] | 0.663 | [0.579, 0.679] | 0.729 | [0.685, 0.767] | 0.712 | [0.677, 0.743] | 0.613 | [0.524, 0.686] | |
Hybrid | IN | 0.848 | [0.835, 0.859] | 0.809 | [0.782, 0.834] | 0.810 | [0.790, 0.828] | 0.814 | [0.793, 0.833] | 0.841 | [0.821, 0.859] | 0.828 | [0.811, 0.843] | 0.841 | [0.821, 0.859] |
AV | 0.892 | [0.880, 0.902] | 0.896 | [0.877, 0.913] | 0.881 | [0.865, 0.895] | 0.858 | [0.838, 0.876] | 0.923 | [0.910, 0.934] | 0.888 | [0.875, 0.901] | 0.923 | [0.910, 0.934] | |
NA | 0.659 | [0.631, 0.687] | 0.662 | [0.612, 0.707] | 0.528 | [0.479, 0.574] | 0.573 | [0.523, 0.618] | 0.671 | [0.621, 0.709] | 0.604 | [0.565, 0.640] | 0.652 | [0.589, 0.708] | |
AN | 0.762 | [0.740, 0.782] | 0.725 | [0.681, 0.763] | 0.769 | [0.742, 0.792] | 0.786 | [0.759, 0.810] | 0.714 | [0.674, 0.749] | 0.764 | [0.740, 0.787] | 0.724 | [0.670, 0.771] | |
EB | 0.578 | [0.534, 0.619] | 0.559 | [0.476, 0.629] | 0.495 | [0.428, 0.554] | 0.535 | [0.468, 0.594] | 0.556 | [0.484, 0.619] | 0.540 | [0.484, 0.590] | 0.553 | [0.449, 0.637] | |
AA | 0.733 | [0.704, 0.758] | 0.666 | [0.603, 0.718] | 0.623 | [0.573, 0.667] | 0.663 | [0.579, 0.679] | 0.729 | [0.685, 0.767] | 0.712 | [0.677, 0.743] | 0.613 | [0.524, 0.686] | |
DYA | 0.647 | [0.609, 0.681] | 0.624 | [0.553, 0.683] | 0.588 | [0.533, 0.636] | 0.589 | [0.530, 0.641] | 0.656 | [0.600, 0.705] | 0.618 | [0.571, 0.659] | 0.609 | [0.519, 0.683] |
Correlation between PTSD factors with depression and number of experienced traumatic events.
IN | 0.054 |
0.260 |
0.059 |
0.602 |
AV | 0.059 |
0.196 |
0.001 | 0.347 |
NA | 0.046 | 0.258 |
0.072 |
0.608 |
AN | 0.061 |
0.248 |
0.173 |
0.653 |
DYA | 0.005 | 0.214 |
0.262 |
0.709 |
EB | 0.064 |
0.242 |
0.132 |
0.611 |
AA | 0.007 | 0.218 |
0.002 | 0.532 |
IN | 0.054 |
0.260 |
0.059 |
0.602 |
AV | 0.059 |
0.196 |
0.006 | 0.347 |
NA | 0.052 |
0.258 |
0.081 |
0.608 |
AN | 0.049 |
0.248 |
0.100 |
0.653 |
DYA | 0.080 |
0.244 |
0.531 |
0.870 |
AA | 0.012 | 0.218 |
0.025 |
0.532 |
IN | 0.051 |
0.260 |
0.046 |
0.602 |
NCBA | 0.088 |
0.286 |
0.324 |
0.746 |
AN | 0.063 |
0.248 |
0.200 |
0.653 |
AV | 0.058 |
0.196 |
−0.018 | 0.347 |
As presented in
Multi group confirmatory factor analysis based on PTSD models.
DSM-5 | 1,104.924 (164) |
0.928 | 0.917 | 0.062 | [0.058, 0.065] | 0.041 | 1,441.760 |
Anhedonia and affect | 995.775 (164) |
0.940 | 0.930 | 0.056 | [0.053, 0.060] | 0.037 | 1,292.611 |
Dysphoria | 1,141.818 (164) |
0.925 | 0.914 | 0.063 | [0.059, 0.066] | 0.042 | 1,478.653 |
Dysphoric arousal | 980.514 (160) |
0.937 | 0.926 | 0.058 | [0.055, 0.062] | 0.039 | 1,346.639 |
Externalizing behaviors | 958.753 (155) |
0.939 | 0.925 | 0.059 | [0.055, 0.062] | 0.039 | 1,361.491 |
Anhedonia | 765.012 (155) |
0.953 | 0.943 | 0.051 | [0.047, 0.055] | 0.033 | 1,167.750 |
Hybrid | 737.766 (149) |
0.955 | 0.943 | 0.051 | [0.047, 0.055] | 0.032 | 1,184.439 |
Single group CFAs (nationality—Iraqi and Syrian; the language of interview—Kurdish and Arabic; ethnicity—Kurd and Arab) for each PTSD model were conducted and results showed that the anhedonia and hybrid models were good at all relevant criteria (CFIs ≥ 0.90, TLIs ≥ 0.90, RMSEAs ≤ 0.06, and SRMRs <0.04; see
Single group confirmatory factor analysis based on PTSD models.
Iraqi | 525.29 (164) |
0.91 | 0.89 | 0.06 | [0.059, 0.071] | 0.04 |
Syrian | 843.06 (164) |
0.90 | 0.88 | 0.06 | [0.060, 0.069] | 0.04 |
Kurdish | 777.76 (164) |
0.89 | 0.88 | 0.06 | [0.062, 0.072] | 0.04 |
Arabic | 595.18 (164) |
0.92 | 0.91 | 0.06 | [0.057, 0.068] | 0.04 |
Kurd | 923.50 (164) |
0.91 | 0.90 | 0.06 | [0.059, 0.067] | 0.04 |
Arab | 428.25 (164) |
0.90 | 0.88 | 0.06 | [0.060, 0.075] | 0.05 |
Iraqi | 533.64 (164) |
0.90 | 0.89 | 0.06 | [0.060, 0.072] | 0.04 |
Syrian | 761.11 (164) |
0.91 | 0.90 | 0.06 | [0.056, 0.065] | 0.04 |
Kurdish | 700.69 (164) |
0.89 | 0.90 | 0.06 | [0.058, 0.067] | 0.04 |
Arabic | 570.01 (164) |
0.93 | 0.91 | 0.06 | [0.055, 0.066] | 0.04 |
Kurd | 808.10 (164) |
0.92 | 0.91 | 0.05 | [0.054, 0.062] | 0.04 |
Arab | 440.94 (164) |
0.89 | 0.87 | 0.06 | [0.061, 0.077] | 0.05 |
Iraqi | 552.22 (164) |
0.90 | 0.88 | 0.05 | [0.061, 0.074] | 0.06 |
Syrian | 863.37 (164) |
0.89 | 0.88 | 0.06 | [0.061, 0.070] | 0.04 |
Kurdish | 800.39 (164) |
0.89 | 0.87 | 0.06 | [0.063, 0.073] | 0.05 |
Arabic | 460.01 (164) |
0.88 | 0.87 | 0.07 | [0.058, 0.069] | 0.05 |
Kurd | 943.16 (164) |
0.91 | 0.90 | 0.06 | [0.060, 0.068] | 0.04 |
Arab | 460.01 (164) |
0.88 | 0.87 | 0.07 | [0.064, 0.079] | 0.05 |
Iraqi | 479.48 (160) |
0.92 | 0.91 | 0.06 | [0.056, 0.068] | 0.04 |
Syrian | 782.43 (160) |
0.91 | 0.89 | 0.06 | [0.058, 0.067] | 0.04 |
Kurdish | 731.50 (160) |
0.90 | 0.88 | 0.06 | [0.060, 0.070] | 0.04 |
Arabic | 526.53 (160) |
0.93 | 0.92 | 0.05 | [0.053, 0.064] | 0.04 |
Kurd | 816.24 (160) |
0.92 | 0.91 | 0.05 | [0.055, 0.064] | 0.04 |
Arab | 408.05 (160) |
0.90 | 0.88 | 0.06 | [0.058, 0.074] | 0.05 |
Iraqi | 740.88 (155) |
0.92 | 0.90 | 0.06 | [0.056, 0.069] | 0.04 |
Syrian | 757.12 (155) |
0.91 | 0.89 | 0.06 | [0.058, 0.067] | 0.04 |
Kurdish | 711.02 (155) |
0.90 | 0.88 | 0.06 | [0.061, 0.070] | 0.04 |
Arabic | 516.19 (155) |
0.93 | 0.92 | 0.05 | [0.053, 0.065] | 0.04 |
Kurd | 790.06 (155) |
0.92 | 0.91 | 0.05 | [0.055, 0.064] | 0.04 |
Arab | 399.77 (155) |
0.90 | 0.88 | 0.06 | [0.059, 0.075] | 0.05 |
Iraqi | 424.73 (155) |
0.93 | 0.91 | 0.05 | [0.051, 0.064] | 0.04 |
Syrian | 663.32 (155) |
0.92 | 0.91 | 0.05 | [0.053, 0.062] | 0.04 |
Kurdish | 606.13 (155) |
0.92 | 0.90 | 0.05 | [0.054, 0.064] | 0.04 |
Arabic | 460.45 (155) |
0.94 | 0.93 | 0.05 | [0.048, 0.060] | 0.03 |
Kurd | 663.29 (155) |
0.94 | 0.93 | 0.05 | [0.049, 0.057] | 0.03 |
Arab | 349.20 (155) |
0.92 | 0.91 | 0.06 | [0.051, 0.068] | 0.04 |
Iraqi | 416.00 (149) |
0.93 | 0.91 | 0.05 | [0.052, 0.065] | 0.04 |
Syrian | 638.85 (149) |
0.93 | 0.91 | 0.05 | [0.052, 0.062] | 0.04 |
Kurdish | 584.01 (149) |
0.92 | 0.90 | 0.05 | [0.054, 0.064] | 0.04 |
Arabic | 447.56 (149) |
0.94 | 0.93 | 0.05 | [0.049, 0.060] | 0.03 |
Kurd | 627.07 (149) |
0.94 | 0.93 | 0.05 | [0.048, 0.057] | 0.03 |
Arab | 339.81 (149) |
0.92 | 0.90 | 0.06 | [0.052, 0.069] | 0.04 |
Testing measurement invariance across groups based on anhedonia and hybrid models.
Configural invariance | 1,088.110 (310) |
0.92 | 0.91 | 0.04 | [0.038, 0.043] | 0.04 |
Metric invariance | 1,206.252 (324) |
0.91 | 0.90 | 0.04 | [0.040, 0.045] | 0.05 |
Scalar invariance | 1,331.118 (345) |
0.91 | 0.90 | 0.04 | [0.041, 0.046] | 0.08 |
Configural invariance | 1,066.579 (310) |
0.93 | 0.92 | 0.04 | [0.038, 0.043] | 0.04 |
Metric invariance | 1,164.512 (324) |
0.92 | 0.91 | 0.04 | [0.039, 0.044] | 0.04 |
Scalar invariance | 1,276.287 (345) |
0.92 | 0.91 | 0.04 | [0.040, 0.045] | 0.06 |
Configural invariance | 1,012.723 (310) |
0.940 | 0.926 | 0.039 | [0.036, 0.041] | 0.03 |
Metric invariance | 1,061.266 (324) |
0.937 | 0.926 | 0.039 | [0.036, 0.041] | 0.03 |
Scalar invariance | 1,156.890 (345) |
0.930 | 0.923 | 0.039 | [0.037, 0.042] | 0.03 |
Configural invariance | 1,044.91 (298) |
0.93 | 0.91 | 0.04 | [0.038, 0.043] | 0.04 |
Metric invariance | 1,161.84 (311) |
0.92 | 0.90 | 0.04 | [0.040, 0.045] | 0.05 |
Scalar invariance | 1,295.11 (339) |
0.91 | 0.90 | 0.04 | [0.041, 0.046] | 0.08 |
Configural invariance | 1,031.57 (298) |
0.93 | 0.92 | 0.04 | [0.038, 0.043] | 0.04 |
Metric invariance | 1,130.79 (311) |
0.93 | 0.91 | 0.04 | [0.039, 0.044] | 0.04 |
Scalar invariance | 1,244.73 (339) |
0.92 | 0.91 | 0.04 | [0.040, 0.045] | 0.06 |
Configural invariance | 967.118 (298) | 0.94 | 0.92 | 0.03 | [0.036, 0.041] | 0.03 |
Metric invariance | 1,012.247 (311) | 0.94 | 0.92 | 0.03 | [0.036, 0.041] | 0.03 |
Scalar invariance | 1,123.460 (339) | 0.93 | 0.92 | 0.03 | [0.037, 0.042] | 0.03 |
Standardized estimates for factor loadings, based anhedonia and hybrid models for each single group.
1 | 0.66 | 0.66 | 0.67 | 0.69 | 0.68 | 0.64 | 0.66 | 0.66 | 0.67 | 0.69 | 0.68 | 0.64 |
2 | 0.70 | 0.61 | 0.60 | 0.75 | 0.66 | 0.70 | 0.70 | 0.60 | 0.60 | 0.75 | 0.66 | 0.70 |
3 | 0.63 | 0.67 | 0.67 | 0.68 | 0.69 | 0.66 | 0.63 | 0.67 | 0.67 | 0.68 | 0.69 | 0.66 |
4 | 0.68 | 0.72 | 0.72 | 0.70 | 0.71 | 0.64 | 0.68 | 0.72 | 0.72 | 0.70 | 0.71 | 0.64 |
5 | 0.75 | 0.71 | 0.72 | 0.76 | 0.74 | 0.72 | 0.75 | 0.71 | 0.72 | 0.76 | 0.74 | 0.73 |
6 | 0.88 | 0.92 | 0.89 | 0.92 | 0.90 | 0.86 | 0.88 | 0.92 | 0.90 | 0.92 | 0.90 | 0.86 |
7 | 0.91 | 0.85 | 0.83 | 0.92 | 0.88 | 0.91 | 0.91 | 0.85 | 0.83 | 0.92 | 0.88 | 0.91 |
8 | 0.36 | 0.27 | 0.30 | 0.45 | 0.36 | 0.35 | 0.36 | 0.20 | 0.30 | 0.44 | 0.35 | 0.36 |
9 | 0.68 | 0.47 | 0.48 | 0.65 | 0.54 | 0.66 | 0.68 | 0.46 | 0.47 | 0.65 | 0.54 | 0.67 |
10 | 0.68 | 0.47 | 0.52 | 0.63 | 0.54 | 0.65 | 0.68 | 0.48 | 0.52 | 0.63 | 0.54 | 0.65 |
11 | 0.62 | 0.60 | 0.62 | 0.62 | 0.63 | 0.63 | 0.62 | 0.60 | 0.62 | 0.63 | 0.63 | 0.63 |
12 | 0.72 | 0.76 | 0.78 | 0.71 | 0.76 | 0.69 | 0.72 | 0.76 | 0.78 | 0.71 | 0.77 | 0.69 |
13 | 0.61 | 0.62 | 0.63 | 0.58 | 0.61 | 0.63 | 0.61 | 0.62 | 0.63 | 0.58 | 0.61 | 0.62 |
14 | 0.72 | 0.81 | 0.83 | 0.72 | 0.80 | 0.72 | 0.72 | 0.81 | 0.83 | 0.72 | 0.79 | 0.72 |
15 | 0.61 | 0.63 | 0.66 | 0.62 | 0.63 | 0.66 | 0.65 | 0.72 | 0.73 | 0.65 | 0.69 | 0.68 |
16 | 0.56 | 0.50 | 0.54 | 0.56 | 0.54 | 0.55 | 0.59 | 0.54 | 0.58 | 0.59 | 0.59 | 0.56 |
17 | 0.64 | 0.71 | 0.72 | 0.70 | 0.74 | 0.62 | 0.64 | 0.70 | 0.71 | 0.70 | 0.74 | 0.62 |
18 | 0.77 | 0.63 | 0.64 | 0.81 | 0.73 | 0.71 | 0.77 | 0.64 | 0.64 | 0.81 | 0.74 | 0.70 |
19 | 0.67 | 0.58 | 0.59 | 0.68 | 0.61 | 0.64 | 0.69 | 0.61 | 0.63 | 0.70 | 0.69 | 0.66 |
20 | 0.62 | 0.64 | 0.63 | 0.67 | 0.66 | 0.61 | 0.65 | 0.67 | 0.66 | 0.69 | 0.64 | 0.65 |
As shown in the
Standardized estimates for factor loadings.
1 | 0.709 | 0.709 | 0.709 | 0.709 | 0.709 | 0.709 | 0.709 |
2 | 0.722 | 0.723 | 0.723 | 0.723 | 0.723 | 0.723 | 0.723 |
3 | 0.716 | 0.716 | 0.716 | 0.716 | 0.716 | 0.716 | 0.716 |
4 | 0.721 | 0.721 | 0.721 | 0.721 | 0.721 | 0.721 | 0.721 |
5 | 0.765 | 0.765 | 0.765 | 0.764 | 0.765 | 0.764 | 0.765 |
6 | 0.910 | 0.911 | 0.911 | 0.910 | 0.910 | 0.906 | 0.906 |
7 | 0.885 | 0.884 | 0.883 | 0.885 | 0.884 | 0.889 | 0.888 |
8 | 0.427 | 0.445 | 0.429 | 0.426 | 0.425 | 0.450 | 0.447 |
9 | 0.588 | 0.571 | 0.576 | 0.590 | 0.589 | 0.595 | 0.594 |
10 | 0.579 | 0.577 | 0.569 | 0.577 | 0.577 | 0.594 | 0.595 |
11 | 0.635 | 0.636 | 0.634 | 0.629 | 0.630 | 0.644 | 0.646 |
12 | 0.710 | 0.774 | 0.688 | 0.709 | 0.709 | 0.769 | 0.769 |
13 | 0.564 | 0.610 | 0.556 | 0.570 | 0.569 | 0.615 | 0.615 |
14 | 0.717 | 0.786 | 0.698 | 0.720 | 0.721 | 0.788 | 0.787 |
15 | 0.656 | 0.645 | 0.639 | 0.671 | 0.713 | 0.671 | 0.710 |
16 | 0.557 | 0.555 | 0.546 | 0.573 | 0.604 | 0.575 | 0.607 |
17 | 0.673 | 0.669 | 0.725 | 0.735 | 0.735 | 0.738 | 0.738 |
18 | 0.712 | 0.698 | 0.747 | 0.787 | 0.788 | 0.784 | 0.784 |
19 | 0.647 | 0.632 | 0.632 | 0.663 | 0.687 | 0.662 | 0.688 |
20 | 0.657 | 0.645 | 0.644 | 0.672 | 0.698 | 0.672 | 0.698 |
Multi group confirmatory factor analysis based on PTSD models after removing item 8.
DSM-5 | 965.454 (146) |
0.936 | 0.925 | 0.061 | [0.057, 0.065] | 0.0394 | 1,287.645 |
Anhedonia and affect | 850.662 (146) |
0.945 | 0.935 | 0.056 | [0.053, 0.060] | 0.0364 | 1,172.853 |
Dysphoria | 1,013.845 (146) |
0.932 | 0.920 | 0.063 | [0.059, 0.066] | 0.0406 | 1,336.036 |
Dysphoric arousal | 840.464 (142) |
0.945 | 0.934 | 0.057 | [0.053, 0.061] | 0.0373 | 1,191.945 |
Externalizing behaviors | 817.863 (137) |
0.946 | 0.933 | 0.057 | [0.054, 0.061] | 0.0369 | 1,205.956 |
Anhedonia | 653.471 (137) |
0.959 | 0.949 | 0.050 | [0.046, 0.054] | 0.0313 | 1,041.564 |
Hybrid | 622.443 (131) |
0.961 | 0.950 | 0.050 | [0.046, 0.054] | 0.0306 | 1054.471 |
Standardized estimates for factor loadings after removing item 8.
1 | 0.710 | 0.709 | 0.709 | 0.710 | 0.710 | 0.709 | 0.709 |
2 | 0.722 | 0.722 | 0.722 | 0.723 | 0.723 | 0.723 | 0.723 |
3 | 0.714 | 0.714 | 0.714 | 0.714 | 0.714 | 0.714 | 0.714 |
4 | 0.723 | 0.723 | 0.722 | 0.722 | 0.722 | 0.723 | 0.723 |
5 | 0.766 | 0.766 | 0.765 | 0.765 | 0.765 | 0.765 | 0.765 |
6 | 0.911 | 0.911 | 0.912 | 0.911 | 0.911 | 0.908 | 0.908 |
7 | 0.884 | 0.883 | 0.883 | 0.883 | 0.883 | 0.887 | 0.886 |
9 | 0.585 | 0.570 | 0.574 | 0.587 | 0.587 | 0.606 | 0.603 |
10 | 0.574 | 0.574 | 0.565 | 0.572 | 0.572 | 0.605 | 0.605 |
11 | 0.639 | 0.643 | 0.639 | 0.633 | 0.634 | 0.661 | 0.662 |
12 | 0.719 | 0.774 | 0.693 | 0.719 | 0.718 | 0.768 | 0.769 |
13 | 0.567 | 0.609 | 0.557 | 0.573 | 0.573 | 0.613 | 0.613 |
14 | 0.730 | 0.787 | 0.705 | 0.733 | 0.733 | 0.790 | 0.789 |
15 | 0.658 | 0.650 | 0.643 | 0.674 | 0.719 | 0.675 | 0.717 |
16 | 0.554 | 0.549 | 0.542 | 0.570 | 0.600 | 0.570 | 0.601 |
17 | 0.674 | 0.668 | 0.727 | 0.734 | 0.734 | 0.738 | 0.738 |
18 | 0.713 | 0.697 | 0.749 | 0.788 | 0.788 | 0.784 | 0.784 |
19 | 0.646 | 0.628 | 0.628 | 0.661 | 0.686 | 0.660 | 0.688 |
20 | 0.657 | 0.645 | 0.642 | 0.673 | 0.699 | 0.673 | 0.698 |
Using epidemiology data about violence and mental health among Iraqi and Syrian displaced people, the current study examined the factor structure and cultural invariance of the DSM-V and six alternative models for PTSD. Although the DSM-V and all other alternative models yielded an acceptable fit to the data, the anhedonia model was superior to all other models tested here. This finding is in line with most of the previous studies among Western (Armour et al.,
The current study is the first study that addresses the validity of the structure of PTSD based on the PCL-5 among diverse languages, nationalities, and ethnicities in the Middle East. Configural, metric, and scalar invariances were obtained by applying anhedonia and hybrid models. This result, along with results from CFAs in the full sample, provides further support for the empirical validity of the anhedonia and hybrid model. However, Armour et al. (
The present study used an exploratory factor analysis and introduced a new, empirically-supported model (the anhedonia and affect model) for the factor structure of PTSD. In this model, symptoms from B and C criterion were highly loaded in two separated factors, and symptoms in D and E factors were mixed across two different factors. The first part in this model is in harmony with the DSM-V, and all other proposed models, since intrusion and avoidance items load onto two specific factors. Regarding to criterion D and E, the anhedonia and affect model is partially in line with the recently-suggested models—the anhedonia (Liu et al.,
In the present study we investigated the correlation between PTSD symptoms clusters and symptoms of depression. We noted that the factors that hosted internalizing symptoms, such as dysphoric arousal, anhedonia, and negative affect, were all associated with depression symptoms higher than items and factors that described externalizing behaviors. This result indicates that a division of externalizing and internalizing symptoms, which had been proposed as a general factor structure of psychopathology, might be replicated within the PTSD category. However, this idea requires further elaboration since only limited externalizing symptoms had been assessed in this study. In particular there is no information about alcohol consumption (Claycomb Erwin et al.,
In line with most of the previous item level and factor analytic studies of PTSD (Wang et al.,
The study's instrument limits the results of the present study. Although a valid and reliable version of the PCL-5 was used in this study that was administered by trained local clinical psychologists and social workers, the PCL-5 is still a self-report and screening instrument with limited validity as a representative of DSM-V symptoms. Previous research showed that there is weak support for the DSM-V model when PCL-5 is applied (Krüger-Gottschalk et al.,
The current study is the first structural equation modeling study of PTSD factor structure among the displaced people in the Middle East. While the DSM-V and all other alternative models for PTSD reached an acceptable fit, the anhedonia model provided the best fit to the data, and the invariance of PTSD was obtained by applying the anhedonia and hybrid model. Overall, the current study provides further support for the global validity of the anhedonia and hybrid model of PTSD, and it contributes to filling the gap in knowledge about the validity of PTSD symptoms clusters among non-Western populations.
The research and its procedures were approved by the Ethical Review Committees of Bielefeld University in Germany and Koya University in the Kurdistan Region of Iraq.
HI and FN conceptualized and designed the study. HI was the co-principal investigator and project manager, trained the local interviewers, supervised data acquisition, performed the data preparation and statistical analysis as well as the interpretation of data, and wrote the manuscript. AI was the co-principal investigator. CC contributed to the interpretation of data. FN was the chief investigator for this study, supervised data analyses, participated in the interpretation of the data, and critically revised the manuscript for important intellectual content.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
We acknowledge the financial support of the German Research Foundation (DFG) and the Open Access Publication Fund of Bielefeld University for the article-processing charge. We express our gratitude to all participants, local interviewers, and support staff involved in this study.