Medical Disorders as a Cause of Psychological Trauma and Posttraumatic Stress Disorder

Elizabeth Mundy; Andrew Baum


Curr Opin Psychiatry. 2004;17(2) 

In This Article

How are Medical Stressors Different?

Despite the outward similarities between medical stressors and well-studied traumatic stressors, there are also important differences that may modify PTSD symptoms or otherwise affect the expression of threat, distress, and disorganization. Perhaps the most important difference is the relative prevalence of PTSD. In general, the likelihood of PTSD is lower among medical patients; among cancer patients approximately 0-32% have been found to exhibit PTSD,[19,20,21,22,23,24] compared with 35-47% in studies of rape or battery.[5,25,26] The rate of PTSD after MI has varied from 8 to 16% depending on the assessment timepoint and sample size. Bennett et al.[27] assessed 75 MI patients on average 3 months post-hospital admission for an MI, and found that 16% of patients met the criteria for PTSD on the basis of the PDS questionnaire. In a second study of 100 MI patients, Kutz et al.[18] also found that 16% of patients met the criteria for PTSD on average 14 months post-MI. Doerfler et al.[28] assessed 50 men who had an MI or received coronary artery bypass surgery, and found that 8% met the DSM-IIIR criteria for PTSD 6-12 months post-cardiac incident. Shemesh et al.[29] followed up 102 MI patients from hospital discharge to 6-12 months post-discharge, and found that 10% met above-threshold criteria for PTSD avoidance and intrusion symptoms. Finally, Bennett and Brooke[30] had completed data on 44 patients who suffered from an MI 6-12 months previously, and found that the rate of PTSD was 10%.

PTSD has been examined in medically ill populations, including cancer, HIV disease, and among patients receiving a heart transplant. Cancer diagnosis and the severe effects of treatment may also produce trauma and stress, and although rates of distress in this population are low and patients seem to cope effectively overall, traumatic stress syndrome has been observed.[31] Similarly, organ transplant can convey a life or death experience for patients. At 12 months post-heart transplant 11% out of 158 patients met the diagnostic interview criteria for PTSD.[32] Being diagnosed with HIV is also life-threatening, and matches other medical illnesses and conditions because of its chronic course and other stressful experiences that can occur as part of the disease, treatment, or context. Kelly et al.[33] interviewed 61 HIV-positive homosexual and bisexual men who had been diagnosed with HIV on average 4 years earlier for the presence of current or past PTSD related to the HIV diagnosis. They found that 30% of HIV-positive men met the criteria for current or past HIV-related PTSD. In a second study of HIV, Matinez et al.[34] assessed 41 women who were HIV positive for the presence of PTSD from a clinic-based sample, and found that 42% of the women were likely to meet the criteria for PTSD on the basis of a questionnaire assessment, but the questionnaire was not tied to specific stressors or PTSD symptoms occurring in response to the HIV diagnosis. Instead, participants were asked to rate their distress and extent of bother by PTSD symptoms in reference to whatever event distressed them the most. If the women were exposed to other traumatic events in their lives, we do not know if the reported rates of PTSD referred exclusively or at all to the HIV diagnosis or were in reference to alternative trauma exposures (e.g. assault, domestic violence).

There are many possible explanations for the lower observed rates relative to other sources of psychological trauma, including the transformation of symptoms, method of assessment, limitations in the assessment of distress, more effective coping, or unexpected benefits of chronic rather than acute stress. The lower incidence of PTSD in medical situations parallels general findings that the development of psychopathology in medical populations is also relatively low. A recent analysis of cancer patients[35] indicated no more distress among patients than in the general population. This is in comparison with generally elevated rates of distress in most victim groups that have more traditionally been linked to PTSD. To some extent this may reflect methodological issues, including limits on the severity of diseases and stages of disease that have been considered, and when assessments are conducted. Frequently, early stage breast cancer samples are studied because of the relative ease of recruitment. The relatively good prognosis of these participants may artificially limit the generalizability or likelihood of experiencing psychological trauma. Heightened symptoms of traumatic stress might be expected immediately before (if anticipated) and after diagnosis, after recurrence of disease, and possibly as the end of treatment approaches as a result of the lack of continuous medical visits for treatment and longer times between follow-up care appointments.[20,21,36,37] These patterns of rising and falling symptom experience contrast with studies of non-medical stressors, in which distress is greatest immediately after the event and decreases (often rapidly) over time.[5,38]

Perhaps the key difference between many medical stressors and more conventional traumatic stressors is the focus of threat in time. For the most part, conventional traumatic stressors are acute events that can give rise to persistent, chronic stress and adjustment difficulties. They are past traumatic events and the impact of the ongoing sequelae of these events (e.g. court proceedings involving a motor vehicle accident, medical pain from soft tissue damage from such an accident) that continue to affect response is less than the effects of the psychological 'blow' of the trauma. Medical stressors share this characteristic if one considers the diagnosis of life-threatening illness as a traumatic stressor, but they also contain a future-oriented aspect in contrast to traditional traumas, representing fears and worries about treatment, survival, recurrence, stigma, and the persistence of life-threat and new dangers yet to come.[39,40] Also, knowledge about disease recurrence can produce greater PTSD symptoms compared to the initial diagnosis, if the degree of life threat is perceived as more intense. Cancer, HIV disease, and other chronic, life-threatening diseases are characterized by often drawn-out periods of treatment and disease-free survival.[31] Life-threat is not an acute stressor, and difficulty with accommodation to this persistent, ongoing threat may be a factor in the other differences between medical and non-medical stressors described above.

If the focus of threat to life is not based on a past event for medical patients but is based on the future, the intrusions and re-experiencing symptoms that occur as part of posttraumatic stress syndromes may be of a different type than those experienced by individuals exposed to traditional traumas. The re-experiencing symptom cluster of PTSD is based on past trauma exposure, rather than future-oriented events. For example, the symptoms constituting this cluster are: Have you had intrusive thoughts about your trauma that have popped into your mind without there being something to remind you of them? Have you had flashbacks to the event, felt that it was happening all over again? Have you had recurrent distressing dreams about the event? Have you experienced physiological arousal symptoms when you were reminded of the event by cues in your environment or thoughts? Have you become very distressed when you were exposed to internal or external cues that reminded you of the trauma? Cancer and MI patients may not be having intrusions that consist solely of the past event, but rather the majority of their intrusions may be future oriented (e.g. Will I live to watch my grandchild get married? Will the cancer progress to the point that I'm in so much pain that I would want to die? Will my family be provided for once I am gone?). Intrusive thoughts could also be associated with past events (e.g. the physician telling me that I have breast cancer and that it has metastasized, the oncologist telling me that the cancer has progressed and the treatment has not been effective, the only treatment now available is experimental). Cancer and MI patients may experience both types of intrusions. The only way to examine this empirically is to ask patients not only 'Have you experienced intrusions?', but to ask them about the content of their intrusive thoughts (e.g. Have the intrusive thoughts been about the past diagnosis, MI, or have they been future oriented?).