Assessment of Post-traumatic Stress and Post-traumatic Stress Disorder in the Cancer Setting
Diagnostic Criteria of Post-traumatic Stress Disorder (PTSD)
PTSD was initially characterized as an anxiety disorder that developed in response to a severe trauma in which an individual experienced, witnessed, or was confronted by actual or threatened death, injury, or loss of physical integrity of self or others. The Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), stipulated for the first time that being diagnosed with a life-threatening illness or learning that one’s child had such an illness qualifies as a stressful event.
In 1994, the application of PTSD to patients with cancer began with the redefinition of the trauma criteria in the DSM-IV to include life-threatening illness. The essential feature of this disorder is the development of characteristic symptoms after exposure to an extreme traumatic stressor. These events elicit responses of intense fear, helplessness, or horror and trigger three clusters of PTSD symptoms. Symptoms from each of the following three clusters must be present for an individual to meet the full criteria for a diagnosis of PTSD:
- Re-experiencing the trauma (nightmares, flashbacks, and intrusive thoughts).
- Persistent avoidance of reminders of the trauma (avoidance of situations, numbing of general responsiveness, and restricted range of affect).
- Persistent increased arousal (sleep difficulties, hypervigilance, and irritability).
These symptoms must last for at least 1 month and cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
Symptoms that last for at least 1 day but less than 1 month and that cause significant distress or impairment in social, occupational, or other important areas of functioning might meet the diagnostic criteria for acute stress disorder (ASD). ASD is often a prodromal to PTSD.
Post-traumatic Stress (PTS) and PTSD in the Cancer Setting
A timely and careful assessment of patients with cancer is critical to identify the symptoms of cancer-related PTS, to note the deleterious impact of the symptoms on functioning, and to plan interventions targeted at the most distressing symptoms. It is also critical that the assessment distinguishes between the full DSM-IV PTSD syndrome (meets all required diagnostic criteria) and PTS-related symptoms only.
The most difficult aspect of PTS assessment in the cancer setting is the determination of precisely when to evaluate the patient. Diagnosis is complicated because cancer is not an acute or discrete event, but is an experience marked by repeated traumas and indeterminate length. Thus, an individual may exhibit the symptoms of PTS at any point from diagnosis through treatment, to treatment completion and, possibly, to recurrence. Patients such as Holocaust survivors, whose history of victimization causes PTSD or its symptoms, can have the symptoms activated by any number of stimuli encountered during their treatment (e.g., clinical procedures such as being inside magnetic resonance imaging or computed tomography scanners). While such patients may have more difficulty in adjusting to cancer and cancer treatment, their symptomatology is likely to vary greatly according to their circumstances. The relative predominance of specific PTS symptoms may wax and wane throughout the cancer experience and beyond.
The definition in the DSM-IV indicates that although PTSD symptoms usually begin within the first 3 months after trauma, there may be a delay of months or even years before symptoms appear.[1,4] These findings support the necessity for long-term monitoring of cancer survivors and their family members.
At least one study found that individuals who have experienced a traumatic event may exhibit early symptoms without meeting the full criteria for a diagnosis of PTSD. Nonetheless, the appearance of these early symptoms was found to predict later development of full PTSD syndrome. These results lend further credence to the need for both repeated and long-term follow-up of individuals exposed to the trauma of cancer. (Refer to the PDQ summary on Adjustment to Cancer: Anxiety and Distress for further information.)
The difficulty in properly diagnosing PTS may be compounded by the overlapping of PTS symptoms with those of other psychiatric disorders and by the time-related aspects of normal adjustment. For example, irritability, poor concentration, hypervigilance, excessive fear, and disturbed sleep are also symptoms of generalized anxiety disorder. Other arousal and avoidance symptoms are common to PTSD, phobias, and panic disorder, but loss of interest, sense of a foreshortened future, avoidance of other people, and sleep impairment might suggest both PTSD and depressive disorders. Even normal reactions to the diagnosis and treatment of life-threatening disease can consist of responses such as:
- Intrusive thoughts.
- Disassociation and depersonalization.
- Sleep disturbances.
- Heightened arousal.
Therefore, clinicians and researchers must be particularly attuned to the causes, duration, and severity of PTSD-like symptoms when considering PTSD among several diagnoses. For instance, in a study of women with breast cancer, 41% reported experiencing “intense fear, helplessness, or horror” (DSM-IV PTSD diagnostic criterion A2); however, on further comprehensive diagnostic interview, only 4% met the full PTSD criteria. Assessment must be able to distinguish between general psychological distress and symptoms of PTSD.
The accurate diagnosis of PTSD also requires the use of reliable and valid instruments. Many studies have used the PTSD module of the Structured Clinical Interview for DSM-III-R–Nonpatient Edition (SCID-NP). This is a clinician-administered, structured clinical interview that is time intensive and may not be feasible in settings without adequately trained mental health professionals. However, one study  investigated the utility of a cost-effective screening tool, the PTSD Checklist-Civilian Version (PCL-C). In this study of 82 women diagnosed with breast cancer assessed 6 to 72 months after cancer treatment, use of the PCL-C resulted in a sensitivity of .60 and specificity of .99. Other cutoff scores for the PCL-C that could be used were discussed, depending on the clinical resources available in specific cancer treatment settings. Most research studies have used the Impact of Event Scale, a self-report of intrusive thoughts; however, it is important to note that this tool can help evaluate PTS symptoms but is not designed to be an assessment procedure for PTSD.
In attempting to diagnose PTSD, it is important to be aware that this disorder is often marked by comorbid psychopathology. Substance abuse, affective disorders, and other anxiety disorders are consistently encountered in samples of people with PTSD.[1,11-13] It has been reported that war veterans with PTSD exhibited substantial comorbid pathology that included major depression (32% to 72%), alcohol dependence (65%), drug dependence (40%), social phobia (50%), and obsessive-compulsive disorder (10%). High rates of concurrent disorders have also been documented in other trauma victims. For example, 40% to 42% of disaster survivors with PTSD also qualified for a diagnosis of major depression, and 20% to 42% met the criteria for concurrent generalized anxiety disorder.[14,15] While this has not yet been studied in cancer patients or survivors, the presence of co-occurring psychiatric disorders in Vietnam War veterans and other trauma victims would indicate that cancer clinicians should be alert to identify and treat such related syndromes in their patients.
The Conceptual Fit of PTS and Cancer
Conceptual and practical problems can arise in the application of PTS to cancer patients and survivors. The basic concept of an extreme traumatic stressor has been described variously as an event involving direct personal experience that involves actual or threatened death or serious injury. This event can be protracted and continuous but is more frequently a single, time-limited event (e.g., rape, natural disaster). In this context, for the person who has experienced a diagnosis of cancer, the exact nature of the trauma is unclear. Is it the actual diagnosis, aspects of the treatment process, information given about recurrence, negative test results, or some other aspect of the cancer experience? Identifying a discrete stressor within the multiple crises that constitute a cancer experience is much more difficult than it is for other traumas. In one study of patients with breast cancer who underwent autologous bone marrow transplant, more PTSD-like symptoms were reported at the time of initial diagnosis.
Another concern regarding conceptual fit is related to re-experiencing the trauma. DSM-IV PTSD diagnostic criterion B requires persistent re-experiencing of the traumatic event, implying that the patient would first encounter a trauma and then, at a later time, re-experience it in various ways. In a study of women with early-stage breast cancer, however, researchers found that the traumatizing aspects of the cancer experience were receiving the diagnosis and waiting for test results from node dissection. Arguing that these “information traumas” are future oriented and tend to cause intrusive worry about the future—not intrusive recollections of past events—the authors questioned whether cancer fits a conceptual model of PTSD trauma. Re-experiencing the trauma is often measured in terms of unwanted intrusive thoughts about the traumatic event. The cognitive processing of a current and ongoing health threat with uncertain outcome might differ significantly from unwanted intrusive thoughts about a single past event. Some researchers have argued that not all intrusive thoughts are negative or indicate re-experiencing a trauma; rather, they might represent appropriate vigilance and attention to potential symptoms that could result in appropriate help-seeking.[6,18]
Conversely, a unique study assessing the physiological reactivity of patients with breast cancer to a personalized imagery script of their most stressful experiences with breast cancer found elevated physiologic responses that were comparable to those of PTSD patients who had experienced other (noncancer-related) traumas. This finding suggests a good fit between patients with cancer and the PTSD trauma model, as it shows comparable symptoms of increased arousal in patients with cancer. Also, in a factor analytic study designed to confirm the presence of the three broad PTSD symptom clusters (re-experiencing, avoidance of reminders, and hyperarousal), researchers found some tentative support for the DSM-IV symptom clusters in a sample of breast cancer survivors.
In a study of 74 women breast cancer survivors interviewed at 18 months postdiagnosis via the SCID, three groups were identified: one meeting the full criteria for PTSD (n = 12), another meeting partial but not full criteria for PTSD (i.e., subsyndromal, n = 5), and a no-PTSD group (n = 47). Further analyses investigated group differences. Some notable factors affecting the full-criteria PTSD group compared with the subsyndromal and no-PTSD groups include the following:
- Significantly higher number of violent traumas (e.g., physical abuse, rape).
- Higher number of anxiety disorders prior to a cancer diagnosis.
- More advanced disease (75% stage III vs. 7% in the subsyndromal group and 6% in the no-PTSD group).
- More extensive surgeries (83% modified radical mastectomy vs. 47% in the subsyndromal group and 38% in the no-PTSD group).
- Higher lifetime prevalence of previous PTSD (42% vs. 7% in the subsyndromal group and 9% in the no-PTSD group).
Further research will be needed to continue to investigate the important question of how well the conceptual model of PTSD as an anxiety response to a major life trauma fits the life experience of patients with cancer. Reviews have argued both in favor of  and against  the continued use of trauma models for conceptualizing the experience of cancer. Others have proposed alternate conceptual models.[6,22]
- American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders: DSM-IV. 4th ed. Washington, DC: American Psychiatric Association, 1994.
- American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders: DSM-IV-TR. 4th rev. ed. Washington, DC: American Psychiatric Association, 2000.
- Greenberg DB, Goorin A, Gebhardt MC, et al.: Quality of life in osteosarcoma survivors. Oncology (Huntingt) 8 (11): 19-25; discussion 25-6, 32, 35, 1994. [PUBMED Abstract]
- Solomon Z, Garb R, Bleich A, et al.: Reactivation of combat-related posttraumatic stress disorder. Am J Psychiatry 144 (1): 51-5, 1987. [PUBMED Abstract]
- Perry S, Difede J, Musngi G, et al.: Predictors of posttraumatic stress disorder after burn injury. Am J Psychiatry 149 (7): 931-5, 1992. [PUBMED Abstract]
- Deimling GT, Kahana B, Bowman KF, et al.: Cancer survivorship and psychological distress in later life. Psychooncology 11 (6): 479-94, 2002 Nov-Dec. [PUBMED Abstract]
- Spitzer RL, Williams JB, Gibbon M, et al.: The Structured Clinical Interview for DSM-III-R (SCID). I: History, rationale, and description. Arch Gen Psychiatry 49 (8): 624-9, 1992. [PUBMED Abstract]
- Andrykowski MA, Cordova MJ, Studts JL, et al.: Posttraumatic stress disorder after treatment for breast cancer: prevalence of diagnosis and use of the PTSD Checklist-Civilian Version (PCL-C) as a screening instrument. J Consult Clin Psychol 66 (3): 586-90, 1998. [PUBMED Abstract]
- Weathers FW, Huska JA, Keane TM: PCL-C for DSM-IV. Boston, Mass: National Center for PTSD-Behavioral Science Division, 1991.
- Sundin EC, Horowitz MJ: Impact of Event Scale: psychometric properties. Br J Psychiatry 180: 205-9, 2002. [PUBMED Abstract]
- Rundell JR, Ursano RJ, Holloway HC, et al.: Psychiatric responses to trauma. Hosp Community Psychiatry 40 (1): 68-74, 1989. [PUBMED Abstract]
- Davidson JR, Foa EB: Diagnostic issues in posttraumatic stress disorder: considerations for the DSM-IV. J Abnorm Psychol 100 (3): 346-55, 1991. [PUBMED Abstract]
- Green BL, Lindy JD, Grace MC: Posttraumatic stress disorder. Toward DSM-IV. J Nerv Ment Dis 173 (7): 406-11, 1985. [PUBMED Abstract]
- Keane TM, Wolfe J: Comorbidity in post-traumatic stress disorder: an analysis of community and clinical studies. J Appl Soc Psychol 20 (21): 1776-88, 1990.
- Smith EM, North CS, McCool RE, et al.: Acute postdisaster psychiatric disorders: identification of persons at risk. Am J Psychiatry 147 (2): 202-6, 1990. [PUBMED Abstract]
- Mundy EA, Blanchard EB, Cirenza E, et al.: Posttraumatic stress disorder in breast cancer patients following autologous bone marrow transplantation or conventional cancer treatments. Behav Res Ther 38 (10): 1015-27, 2000. [PUBMED Abstract]
- Green BL, Rowland JH, Krupnick JL, et al.: Prevalence of posttraumatic stress disorder in women with breast cancer. Psychosomatics 39 (2): 102-11, 1998. [PUBMED Abstract]
- Palmer SC, Kagee A, Coyne JC, et al.: Experience of trauma, distress, and posttraumatic stress disorder among breast cancer patients. Psychosom Med 66 (2): 258-64, 2004 Mar-Apr. [PUBMED Abstract]
- Cordova MJ, Studts JL, Hann DM, et al.: Symptom structure of PTSD following breast cancer. J Trauma Stress 13 (2): 301-19, 2000. [PUBMED Abstract]
- Shelby RA, Golden-Kreutz DM, Andersen BL: PTSD diagnoses, subsyndromal symptoms, and comorbidities contribute to impairments for breast cancer survivors. J Trauma Stress 21 (2): 165-72, 2008. [PUBMED Abstract]
- Gurevich M, Devins GM, Rodin GM: Stress response syndromes and cancer: conceptual and assessment issues. Psychosomatics 43 (4): 259-81, 2002 Jul-Aug. [PUBMED Abstract]
- Cordova MJ, Andrykowski MA: Responses to cancer diagnosis and treatment: posttraumatic stress and posttraumatic growth. Semin Clin Neuropsychiatry 8 (4): 286-96, 2003. [PUBMED Abstract]