Traumatic Stressors and Post-Traumatic Stress Disorder Symptoms in Headache Patients
From Orofacial Pain Center (Dr. de Leeuw), Department of Psychology (Drs. Schmidt and Carlson), University of Kentucky, Lexington, KY.
Address all correspondence to Dr. Reny de Leeuw, Orofacial Pain Center, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0297.
Objective.—The aim of this study was to assess the prevalence of significant traumatic stressors and post-traumatic stress disorder (PTSD) symptoms in a headache population.
Background.—Several recent publications have emphasized the relationship between life stressors and/or daily hassles and recurrent headaches. However, little is known about the prevalence and impact of major traumatic stressors in patients with recurrent headaches.
Methods.—Eighty patients with either migraine or tension-type headache completed a PTSD checklist. Data were compared with those from patients with chronic masticatory muscle pain of similar intensity and duration.
Results.—Almost 64% of the headache patients reported one or more major traumatic stressors. This percentage was not significantly different from that of the comparison group, and fell within the broad range reported for exposure to traumatic stressors in epidemiologic studies with nonpatient populations. One out of 6 patients in the total headache sample, and 1 out of 4 of those reporting a traumatic stressor, reported symptoms suggestive of current PTSD. The prevalence of current PTSD-like symptomatology reported by the headache patients was comparable to that of the comparison group of the present study, but higher than that reported for the general population in the available literature printed in English. Traumatic stressors most often reported were not related to direct physical trauma, but rather associated with loss or serious illness of a loved one.
Conclusion.—Exposure to traumatic events in patients with a primary diagnosis of recurrent headaches is similar to that reported for chronic masticatory muscle pain patients or nonpatient populations. However, symptoms consistent with a diagnosis of current PTSD appear to be more frequent in patients with recurrent headaches than reported in the scientific literature printed in English for nonpatient populations. Screening for PTSD symptomatology is recommended as part of the routine clinical evaluation of headache.
post-traumatic stress disorder
Diagnostic and Statistical Manual of Mental Disorders, 4th edition
PTSD Check List-Civilian
multidimensional pain inventory
Several studies have emphasized the important role of stress and daily hassles on the onset, frequency, and persistence of headaches.1–8 Many of these papers focused on the differences between life events that lead to significant adjustment difficulties in the individual and daily hassles, or recurrent aggravations related to daily living. Although data are not entirely uniform,4 there is evidence that patients with tension-type headache experience a greater number of minor stressful events in their everyday lives5,7–10 and that they appraise these events as more stressful than headache-free controls.5,7,9–11
Little is known about the prevalence of major traumatic stressors as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV)12 and symptoms of post-traumatic stress disorder (PTSD) in recurrent or chronic headache patients. PTSD is an anxiety disorder that can develop following an individual's exposure to an event perceived to be life-threatening or traumatic. The DSM-IV defines PTSD as “the development of characteristic symptoms following exposure to an extreme traumatic stressor involving direct personal experience of an event that involves actual or threatened death or serious injury, or other threat to one's physical integrity; or witnessing an event that involves death, injury or a threat to the physical integrity of another person; or learning about unexpected or violent death, serious harm or threat of death or injury experienced by a family member or other close associate.” Examples of direct personal traumatic stressors include, for instance, a severe motor vehicle accident, serious injury, violent assault (eg, physical attack, sexual assault), terrorist attack, military combat, or natural or man-made disasters. Examples of witnessed traumatic stressors may include but are not limited to observing any of the previously mentioned stressors. According to the definition of the DSM-IV, learning about, for example, a serious injury or sudden death of a family member or close friend can be considered a major traumatic stressor as well. Any of these traumatic events, whether personally experienced, witnessed, or learned about may lead to PTSD depending on the response of the person experiencing the traumatic event. The characteristic symptoms related to PTSD include persistent reexperiencing of the traumatic event, nightmares, recurrent and intrusive recollections, avoidance of the situations associated with the traumatic event, sleeplessness, and hypervigilance.12
Reports of PTSD in patients who suffer from post-traumatic headache range from 29% to 75%.13–15 To the best of our knowledge there are no reports on the prevalence of other traumatic life stressors in those with chronic headache in studies printed in English. Traumatic stressors as well as symptoms of PTSD are prevalent in chronic pain patients and have been associated with reduced psychosocial functioning.16 For example, Sherman et al found that more than 50% of a sample of patients with fibromyalgia displayed PTSD symptomatology.17 They found that PTSD symptomatology was significantly associated with pain, disability, and coping difficulties. Recently, de Leeuw et al18,19 demonstrated that 50% of patients with chronic temporomandibular disorders endorsed having experienced one or more traumatic stressors. As many as 28% of those patients reporting a traumatic stressor showed symptoms consistent with a diagnosis of PTSD.19 Besides higher levels of psychological distress such as anxiety and depression, orofacial pain patients with current PTSD symptomatology reported more sleep disturbances, and, similar to the findings of Sherman et al, were more often disabled and classified as dysfunctional according to their responses on the multidimensional pain inventory (MPI) than patients without current PTSD symptomatology. In addition, the presence of psychological dysfunction may interfere with successful treatment outcomes in chronic pain patients.20,21 A preliminary study suggested that PTSD treatment alone can positively influence chronic pain conditions and disability.22 Taken together, these findings suggest that the presence of PTSD symptomatology in chronic pain populations is high and may have significant impact on the patient's well-being. Hence, it is important to both clinicians and patients that such disorders are adequately screened for during the diagnostic process, and that appropriate treatment or referral is initiated.
The objective of this article was to assess the prevalence of traumatic stressors and PTSD-like symptomatology in a headache population who consulted a tertiary pain center for evaluation of recurrent headaches. It was hypothesized that the prevalence of traumatic stressors as well as PTSD symptomatology in recurrent headache patients would be higher than that previously reported for the general population (historical controls), but similar to that of other chronic pain populations seeking care at tertiary pain clinics.
Patient Sample.— The total headache patient sample consisted of 80 patients, who consulted the Orofacial Pain Center between October 1997 and October 2002 for evaluation of a primary complaint of headaches (Table 1). These patients had received a primary diagnosis of either tension-type headache (n = 38) or migraine (n = 42) according to criteria established by the International Headache Society;23 however, additional headache subclassifications were not documented. To compare data of the chronic headache patients group with data from another chronic pain population, a group of 80 masticatory muscle pain patients reporting to the same clinic were used. This group of patients had a primary diagnosis of masticatory myofascial pain according to the criteria established by Travell and Simons.24 These criteria included the presence of one or more trigger points in taut muscle bands of the masticatory muscles. The trigger point had to produce exquisite tenderness upon palpation, and palpation of such trigger point had to result in referred pain. The patients were matched to the headache patients based on sex, age, pain duration, and pain severity (Table 2).
Table 1.—. Comparison of Gender, Age, Pain Duration, and Pain Severity Between Patients With Migraine and Patients With Tension-Type Headache
|Males|| 6 (14.3)||11 (28.9)|| |
|Females||36 (85.7)||27 (71.1)|| |
|Total||42 (52.5)||38 (47.5)||χ2= 2.563||.109|
|Age||39.1 ± 13.7||35.1 ± 9.7 || t = 1.477||.144|
|Pain duration in months||77.3 ± 95.7||56.3 ± 95.5|| t = 0.931||.355|
|Pain severity (0 to 10)||7.5 ± 2.3||6.9 ± 2.2|| t = 1.099||.275|
Table 2.—. Headache and Muscle Pain Patients Matched With Regard to Gender, Age, Pain Duration, and Pain Severity
|Males||17 (21.3)||16 (20) || |
|Females||63 (78.8)||64 (80) || |
|Age||37.2 ± 12.1 (SD)||37.8 ± 12.2 (SD)|| t = 0.287||.774|
|Pain duration (months)||67.4 ± 95.5 (SD)||68.8 ± 80.6 (SD)|| t = 0.100||.920|
|Pain severity (0 to 10)||7.2 ± 2.2 (SD)||7.4 ± 2.0 (SD)|| t = 0.511||.610|
|Endorsed stressor||51 (63.8)|| 43 (53.8)*||χ2= 1.651||.199|
|Group A||13 (16.3)||17 (21.5)||χ2= 4.179||.124|
|Group B||38 (47.5)||25 (31.6)|| |
|Group C||29 (36.3)||37 (46.8)|| |
Measures.— In accordance with routine clinic protocol, all new patients completed an orofacial pain questionnaire and a battery of psychological questionnaires. The questionnaires of interest for this study were the orofacial pain questionnaire and the PTSD Check List-Civilian (PCL-C).25 The orofacial pain questionnaire solicits a variety of answers with regard to variables such as the onset, duration, quality, and severity of the pain; precipitating, aggravating, and relieving factors; headaches; jaw dysfunction; oral parafunctional habits; stress; sleep; diet; and treatment modalities. It also contains a medical health history. The PCL-C is a self-report measure used to assess the incidence of significant stressors and prevalence of PTSD symptomatology. Preceding the completion of this questionnaire, the patient is asked to identify significant traumatic stressors from a 15-item list that includes experiences such as military combat, violent attack, incarceration, natural or man-made disaster, severe auto accident, sudden injury/serious accident, observed someone hurt or killed, and learned that your child has a life-threatening illness (Table 3). These items are based on a variety of experiences included in the diagnostic criteria for traumatic exposures according to the DSM-IV.12
Table 3.—. Solicited Stressors, Frequency of Endorsed Stressors, and Most Significant Stressors
|Violent attack||12 (23.5)||10 (23.8)||0.001||1.000||10 (20.8)||5 (13.2)|
|Being kidnapped||1 (2.0)||0 ||N/A||N/A||0 ||0 |
|Taken hostage||0 ||1 (2.4)||N/A||N/A||0 ||1 (2.6) |
|Natural or man-made disaster|| 7 (13.7)||3 (7.1)||1.040|| .503||2 (4.2)||2 (5.3) |
|Severe auto accident|| 9 (17.6)||14 (33.3)||3.045|| .095||3 (6.3)||5 (13.2)|
|Diagnosed with life-threatening illness||2 (3.9)|| 5 (11.9)||2.109|| .238||1 (2.1)||3 (7.9) |
|Sudden injury/serious accident||13 (25.5)||12 (28.6)||0.111|| .816||2 (4.2)||2 (5.3) |
|Observed someone hurt or killed†||11 (21.6)|| 9 (21.4)||0.000||1.000||3 (6.3)||3 (7.9) |
|Learned family member/close friend hurt or killed†||29 (56.9)||22 (52.4)||0.187|| .681||18 (37.5)||9 (23.7)|
|Learned child has life-threatening illness†||1 (2.0)||3 (7.1)||1.503|| .324||1 (2.1)||2 (5.3) |
|Other†|| 9 (17.6)||12 (28.6)||1.572|| .225|| 8 (16.7)||5 (13.2)|
If the person completing this questionnaire endorses one or more traumatic stressors, s/he is prompted to identify the most significant stressor and note the date of occurrence. A person who identifies one or more traumatic stressors on the first part of the questionnaire is prompted to complete the second part of the questionnaire. This part consists of 17 items, each corresponding to a DSM-IV12 PTSD symptom (Table 4), for which s/he is asked to indicate how much s/he has been bothered by each symptom in the past month on a 5-point Likert scale from 1 (not at all) to 5 (extremely) with regard to that most significant stressor. The PCL-C provides a total score and subscale scores for each of the three DSM-IV PTSD symptom clusters: reexperiencing, avoidance/numbing, and arousal. The PCL-C has exhibited test–retest stability (r = 0.96), good overall internal consistency (α= 0.92), and provides a valid and reliable assessment of the presence of PTSD symptoms.26 A score of 41 on the PCL total score is generally considered the cutoff point for clinical significance of PTSD-positive symptomatology.26 The PCL-C has demonstrated efficacy in the screening for PTSD symptoms in orofacial pain patients. The study showed that a PCL-C cutoff score of 41 resulted in a sensitivity of 82%, a specificity of 92%, a negative predictive power of 94%, and a positive predictive power of 77% when using the Structured Clinical Interview for PTSD as the gold standard.27
Table 4.—. The PTSD Checklist-Civilian Version (PCL-C)25
| 1||Repeated, disturbing memories, thoughts, or images of the stressful experience||1||2||3||4||5|
| 2||Repeated, disturbing dreams of the stressful experience||1||2||3||4||5|
| 3||Suddenly acting or feeling as if the stressful experience were happening again (as if you were reliving it)||1||2||3||4||5|
| 4||Feeling very upset when something reminded you of the stressful experience||1||2||3||4||5|
| 5||Having physical reactions (eg, heart pounding, trouble breathing, sweating) when something reminded you of the stressful event||1||2||3||4||5|
| 6||Avoiding thinking about or talking about the stressful experience or avoiding having feelings related to it||1||2||3||4||5|
| 7||Avoiding activities or situations because they reminded you of the stressful experience||1||2||3||4||5|
| 8||Trouble remembering important parts of the stressful experience||1||2||3||4||5|
| 9||Loss of interest in activities that you used to enjoy||1||2||3||4||5|
|10||Feeling distant or cutoff from other people||1||2||3||4||5|
|11||Feeling emotionally numb or being unable to have loving feelings for those close to you||1||2||3||4||5|
|12||Feeling as if your future somehow will be cut short||1||2||3||4||5|
|13||Trouble falling or staying asleep||1||2||3||4||5|
|14||Feeling irritable or having angry outbursts||1||2||3||4||5|
|15||Having difficulty concentrating||1||2||3||4||5|
|16||Being super alert, or watchful, or on-guard||1||2||3||4||5|
|17||Feeling jumpy or easily startled||1||2||3||4||5|
Based on data from the PCL-C, the study samples were divided into three groups. The first group consisted of patients who endorsed exposure to one or more traumatic stressors and whose PCL-C total score was 41 or higher (group A). The second group consisted of patients, who endorsed exposure to one or more traumatic stressors, but whose PCL-C total score was less than 41 (group B). The third group consisted of a control group of the patients who did not endorse exposure to traumatic stressors (group C) and hence did not complete the second part of the questionnaire.
Statistical Analysis.— All statistical analyses were performed using the Statistical Package for the Social Sciences, Release 12.0 (SPSS Inc, Chicago, IL, USA). Frequency of primary diagnoses and differences on demographic variables among the three groups were determined using chi-square tests. Differences in continuous variables between the headache and muscle pain groups were tested with Student's t-test. Differences in continuous variables between the PTSD subgroups within the headache and muscle pain groups were tested with ANOVA, applying Bonferroni corrections. An adjusted α of 0.01 was used to balance both type I and type II error rates.
Demographics.— The total headache sample consisted of 80 patients with either tension-type headache (n = 38; 11 males and 27 females) or migraine (n = 42; 6 males and 36 females) as primary diagnosis. Eight patients were diagnosed with both migraine and tension-type headache (7 had a primary diagnosis of migraine and a secondary diagnosis of tension-type headache). Seven patients with a primary diagnosis of tension-type headache had received a secondary diagnosis of masticatory myofascial pain. All headache patients reported to have two or more headaches per week. There were no significant differences in age, gender, pain severity, or pain duration between the two headache groups (P > .01; Table 1). There were no significant differences in the PCL-C total score (t = 0.655; P= .516) or classification into the three PTSD subgroups (χ2= 1.478; df = 2; P= .478) between the two headache groups. Preliminary analyses of both headache groups with regard to age, gender, pain duration and severity, and the presence or absence of PTSD symptomatology were not significantly altered by inclusion or exclusion of the 8 patients with both migraine and tension-type headache diagnoses. Comparison between the migraine groups with and without a secondary diagnosis of tension-type headache did not reveal any significant differences with regard to these variables either. Hence, it was decided to combine the two headache groups for further statistical analyses.
Data from the combined headache group were compared with data from a group of 80 patients with a primary diagnosis of masticatory myofascial pain. These patients were group-matched on the basis of age, pain duration, pain severity, and gender (Table 2). Four of these patients had a secondary diagnosis of tension-type headache. Preliminary analyses of both the headache and the muscle pain patient groups with regard to age, gender, pain duration and severity, and the presence or absence of PTSD symptomatology were not significantly altered by inclusion or exclusion of the four muscle pain patients with a secondary diagnosis of tension-type headache and the 7 headache patients with a secondary diagnosis of masticatory myofascial pain. Hence, it was decided to include these 11 patients in the study.
Stressors.— Fifty-one headache patients (64%) and 43 muscle pain patients (54%) endorsed one or more significant traumatic stressors (Table 2). The PCL-C total score exceeded the cutoff score of 41 in 13 headache patients (25.5% of headache patients reporting a traumatic stressor; 16.3% of total sample), and 17 muscle pain patients (40.5% of muscle pain patients reporting a traumatic stressor; 21.5% of the total sample). Thirty-eight headache patients and 25 muscle pain patients endorsing a stressor did not exceed the cutoff score. Twenty-nine headache patients and 37 muscle pain patients did not report a stressor. The distribution was not significantly different between the two samples (P= .124; Table 2). One-way ANOVA revealed there were no differences with regard to age (headache patients: F = 0.808; df = 2; P= .449; muscle pain patients: F = 2.146; df = 2; P= .124), headache/pain duration (headache patients: F = 0.991; df = 2; P= .376; muscle pain patients: F = 0.211; df = 2; P= .810), or headache/pain severity (headache patients: F = 1.664; df = 2; P= .196; muscle pain patients: F = 0.393; df = 2; P= .677) between PTSD subgroups of either patient sample.
Significant traumatic stressors most often reported by both groups were “learned about family member or close friend who was hurt or killed,”“sudden injury/serious injury,”“severe auto accident,”“observed someone hurt or killed,” and “violent attack” (Table 3). Of those who endorsed exposure to traumatic stressors, 29 out of 51 headache patients (57%) and 19 out of 42 muscle pain patients (45%) reported one major traumatic stressor. Nine headache patients (17.6%) and 10 muscle pain patients (23.8%) reported two traumatic stressors and another 9 headache patients (17.6%) and 6 muscle pain patients (14.3%) reported three traumatic stressors. The remaining patients (4 headache patients and 7 muscle pain patients) marked four or more stressors. There were no significant differences in the distribution of the number of reported stressors between the headache and the muscle pain group (χ2= 2.709; P= .439). The mean number of distinct events in those patients endorsing traumatic stressors was 2 in both groups (headache patients: mean = 1.9, SD = 1.4; muscle pain patients: mean = 2.1, SD = 1.5; t = 0.952; P= .334).
When prompted to mark which was considered to be “the most significant stressor,” the stressor “learned about family member or close friend who was hurt or killed” was endorsed most often by both groups, followed by “violent attack” and “other.” Chart reviews revealed that the category “other” comprised mostly traumatic stressors relating to death or life-threatening illnesses in family and friends. To examine whether direct types of stressors were more likely to elicit PTSD symptoms than observational types of traumatic events, the stressors were divided into either directly or indirectly (ie, observed or hearsay) experienced traumatic stressors (Table 3). For this purpose the category “other” was treated as an indirect stressor, based on the results of previous chart reviews. The difference between the two patient groups with regard to directly (headache patients: 36% and muscle pain patients: 47.4%) or indirectly (headache patients: 64% and muscle pain patients: 52.6%) experienced stressors was not statistically significant (χ2= 1.154; P= .283). Similar results were achieved when the category “other” was excluded from the analyses (χ2= 0.900; P= .343). In both patient groups, patients endorsing directly experienced traumatic events were two times more likely to report PTSD symptomatology than patients endorsing indirectly experienced traumatic events. Chi-square tests did not show significant differences (Table 5).
Table 5.—. Relationship Between Type of Traumatic Event and PTSD Symptomatology
|Headache (n = 48)*|
| Direct traumatic event||6 (33.3)||12 (66.7)||χ2= 1.343 |
Odds ratio = 2
| Indirect traumatic event||6 (20) ||24 (80) || |
|Muscle pain (n = 37)*|
| Direct traumatic event||9 (50) ||9 (50) ||χ2= 1.029 |
Odds ratio = 2.2
| Indirect traumatic event||6 (31.6)||13 (68.4)|| |
This study showed that exposure to traumatic stressors was rather frequent (almost 64%) in this sample of headache patients, and was not significantly different from the exposure endorsed by the comparison group of patients with masticatory muscle pain (54%). According to epidemiologic studies, the exposure to traumatic events in these two chronic pain patient groups appears similar to that of nonpatient populations, in which reported exposure rates ranged from 39% to 69%.28–30 However, our numbers could be considered low compared to those of Breslau et al who reported a life time exposure of almost 90% in a community sample of 2181 persons between 18 and 45 years of age, given the fact that both studies used the criteria for traumatic stressors as listed in the DSM-IV.31 Possible explanations for the differences between their data and ours may be found in the use of different questionnaires, recall difficulties, and/or information bias. Patients in our study may have omitted items deliberately or may not have given in depth thought to the questionnaire that was distributed as part of a routine battery of psychometric measures. Conversely, participants in the study by Breslau et al may have overreported because the focus of attention was specifically directed toward traumatic events. This could potentially explain why in our sample the mean number of distinct events in those endorsing traumatic events was only 2, whereas in the study by Breslau the mean number of distinct events was almost 5.31
In about 25% of the headache patients who reported a traumatic stressor, symptoms highly suggestive of PTSD were present. This is consistent with the findings of Green who reported in a review paper that about 25% of those exposed to traumatic events develop PTSD.32 In contrast, of those endorsing traumatic events in the muscle pain group of our study, 40% reported symptoms highly suggestive of PTSD. Thus, although fewer muscle pain patients than headache patients reported traumatic stressors (54% vs. 64%), more muscle pain patients than headache patients reported PTSD symptomatology (40% vs. 25%). This difference could not be explained by the number of stressors endorsed. A possible explanation could be related to the greater likelihood of directly experienced traumatic events to result in PTSD symptomatology. Our study showed that patients reporting directly experienced traumatic events were twice as likely to report PTSD symptomatology as patients reporting indirectly experienced traumatic events. However, even though the muscle pain patients reported more often directly experienced types of stressors than the headache patients, the difference was not statistically significant. Another potential explanation might be that the muscle pain patients possess less effective coping skills than patients with chronic pain from other origins. In line with this thought, several studies have found that chronic masticatory muscle pain patients fit more often into the dysfunctional or interpersonally distressed profiles and less into the adaptive coper profile as derived from the MPI33 than patients with chronic pain originating from the temporomandibular joint.34–36 Data also suggest that patients with dysfunctional or interpersonally distressed profiles may be at greater risk for developing PTSD.37 Consistent with this concept, we recently found that the majority of temporomandibular disorder patients with PTSD symptomatology were classified as dysfunctional, whereas the majority of temporomandibular disorder patients without PTSD symptomatology were classified as adaptive copers.19 Available data on MPI profiles in headache patients are inconsistent. One study indicated that almost 60% of chronic headache patients were classified in a cluster resembling that of the dysfunctional profile of the MPI and about 20% in a cluster resembling the adaptive coper profile.38 A more recent study, however, revealed that only 19% of migraine patients were classified as dysfunctional and 52% were classified as adaptive copers.39 Given the results of these studies it is not clear whether differences in coping skills between headache and muscle pain patients could explain the higher rate of PTSD-like symptoms in muscle pain patients. It also seems feasible that the difference in directly experienced traumatic events between the studied samples of headache and muscle pain patients could be an essential factor. Both avenues might be worthwhile exploring further.
Lifetime prevalence estimates of PTSD in the general population range from 1% to 14%.12,40–42 Current PTSD prevalence rates, however, appear to be less than 10%.29,30,43 Given these data, the prevalence of current PTSD symptomatology in the present samples of headache and masticatory muscle pain patients is high. More than 16% of the headache patients and 21.5% of the patients with masticatory muscle pain reported current symptoms consistent with a diagnosis of PTSD. These numbers are comparable to that of previous studies involving orofacial pain patients.19,27,44 However, it appears that the current prevalence of PTSD-like symptomatology in patients with recurrent headaches or orofacial pain conditions is lower than that found in patients with fibromyalgia (over 50%).17,45 Thus, although symptoms consistent with a diagnosis of current PTSD in recurrent headache and masticatory muscle pain patients may not be as prevalent as in patients with chronic widespread pain conditions, they appear to be more prevalent than in the general population.
This study is one of the first studies exploring the prevalence of traumatic stressors and PTSD symptomatology in patients with recurrent headaches. The tool used in this study to establish the presence of traumatic stressors and symptoms characteristic of PTSD is a widely used instrument in the trauma literature, and has shown good reliability and validity.27 The PCL-C has been validated against the Structured Clinical Interview for PTSD in a chronic orofacial pain sample and has shown high validity and reliability.27 However, this instrument has not yet been validated in chronic headache patients. In addition, as a self-report instrument it is a subjective measure and may not necessarily yield the same results as, for instance, a structured interview would. Therefore, this instrument should not replace other identification methods used to diagnose PTSD, but as an initial screening tool for PTSD symptomatology, it appears to be an efficient instrument.
Because we used the PCL-C as a PTSD screening tool, the prevalence of PTSD in recurrent headache patients could potentially be higher or lower than the percentage estimated based on data of our study. As stated in the introduction, chronic tension-type headache patients appear to appraise minor stressful events as more stressful than headache-free controls.5,7,9–11 It is not known whether this trend holds true for recurrent migraineurs, or for appraisal of major traumatic stressors, but if either one or both were the case, this could have skewed the results to a higher percentage of patients diagnosed with PTSD in this study. Another issue that might potentially result in over-diagnosing PTSD in chronic pain patients is related to the fact that several items on the PCL-C, for example, “trouble falling asleep” and “difficulty concentrating,” could be elevated because of the painful condition. Further research with regard to the items of the PCL-C related to numbing and arousal in chronic pain patients regardless of exposure to traumatic events might elucidate the consequences of this potential overlap.
Conversely, several factors could have resulted in under-diagnosing the percentage of patients with PTSD. It is possible that completing the PCL-C as part of a comprehensive battery of psychometric questionnaires may have resulted in a less dutiful completion of the questionnaires by the patient, which may have resulted in under-reporting of traumatic stressors and PTSD symptomatology. In addition, lack of anonymity may also have contributed to underreporting. Administering the PCL-C under different circumstances may shed more light on this issue. Given the possible underestimated percentage of recurrent headache patients with PTSD, exploring this area and its potential associations with pain severity, disability, and coping skills, as well as its probable effects on treatment outcomes, seems warranted.
Another limitation of this study was the small number of male patients included in this study sample. This was due to the fact that in general women are overrepresented in several chronic pain conditions, including headaches and musculoskeletal disorders. The small number of male patients precluded meaningful statistical comparisons between males and females and hence restricts generalizability of the results for male patients.
Generalizability of the results from the current study is further limited by the fact that the patient samples were derived from a tertiary pain management facility.
This study suggests that exposure to traumatic stressors as defined in the DSM-IV12 in patients with recurrent headaches is similar to that reported in the scientific literature printed in English for nonpatient populations. However, the presence of PTSD symptomatology appears higher than reported for the general population. Almost 1 out of 6 patients with recurrent headaches reported symptoms suggestive of PTSD. This pattern was very similar to that of chronic masticatory muscle pain patients. These results suggest that routine screening for PTSD in recurrent headache patients may be warranted in order to provide comprehensive symptom management.