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Impaired Memory and General Intelligence Related to Severity and Duration of Patients' Disease in Type A Posttraumatic Stress Disorder

Posted on: Sunday, 4 September 2005, 03:01 CDT

Studies of short-term memory and general intelligence associated with duration and severity of posttraumatic stress disorder (PTSD) on observed Type A scores are rare. The authors' aim was to assess Type A behavior and identify subgroups of patients who performed most poorly on memory and intelligence tests and Type A scores related to the severity and duration of their disease. They administered nonverbal memory and intelligence tests to 30 men with PTSD and 20 men without PTSD who responded. During their initial contact with the participants, 2 experts assessed 3 major coronary- prone characteristics (hyperalertness, tight facial musculature, and explosive speech). They found significant differences between the PTSD and control groups in total Type A scores. Those with the most severe PTSD performed most poorly on visual retention tests and showed the highest scores on self-reported and subjective diastolic blood pressure reactivity during magnetic resonance imaging. In the PTSD group, high error scores on the visual retention test predicted Type A behavior and low scores on the picture memory block design tests predicted high Type A scores. A significant positive correlation was found between Type A and clinician-assessed subjective distress, whereas the correlations were significantly negative between picture memory and Type A behavior. Suppressed fear is commonly associated with PTSD; decades of research on Type A behavior have isolated fear as a crucial factor in cardiovascular disease.

Index Terms: hippocampus, impaired memory, intelligence, posttraumatic stress disorder (PTSD), Type A behavior

Posttraumatic stress disorder (PTSD) is anxiety that occurs as a result of exposure to an extreme traumatic stressor that involves the threat of death or serious injury. Psychiatrists list symptoms of PTSD in 3 categories: (1) intrusive symptoms, (2) avoidant symptoms, and (3) symptoms of hyperarousal. In this study, we focus on observed hyperarousal and short-term memory. Hyperarousal symptoms may involve bouts of irritability, problems with attention and concentration, hypervigilance, and an increased startle response. The traumatic experience in PTSD can have a negative impact on a sense of self-integration; it may also lead to cognitive problems (impaired memory and intelligence), affective and behavioral changes (poor body language, such as tight facial musculature, explosive speech, and hyperalertness), a constellation of behaviors that make up the trauma survivor's self- disorganization.1-3

In PTSD, the nervous system seems to be overwhelmed and overaroused by trauma, and relaxation becomes very difficult. Hyperarousal is often accompanied by individuals' scanning for signs of threat and becoming very vigilant for potential dangers in the outer world. Hyperarousal also develops when too much is going on around the individual at one time. Previous research indicates that PTSD may be associated with stable neurobiological alterations in both the central and autonomie nervous systems. Psychophysiological alterations associated with PTSD include hyperarousal of the sympathetic nervous system.4 Symptoms included in the criterion D from DSM-IV (2003)5 or hyperarousal criterion most closely resemble those seen in panic and generalized anxiety disorder. The hypervigilance in PTSD may sometimes become so intense that it appears to be frank paranoia.

Trauma is a concept that originally referred to bodily injury. In everyday language, however, it is now generally applied to the psychological consequences of a highly stressful event, and people frequently use the word trauma to mean an extremely stressful event. The key to understanding traumatic events is to recognize that the term refers to an experience that overwhelms an individual's ability to cope. No clear distinction is made between stress experiences that lead to trauma and stress experiences that lead to adaptation. Although stress reactions are clearly physiological as well, different experts in the field define psychological trauma in different ways. In this article, we emphasize that it is the individual's subjective experience that determines whether an event is traumatic. The key phrase here is the sense of helplessness that makes an event traumatic.

Psychological trauma is the unique individual experience of an event or enduring conditions in which (1) individuals' abilities to integrate their emotional experience are overwhelmed, or (2) individual experiences are seen (subjectively) as a threat to life, bodily integrity, or sanity. This fairly broad definition of trauma includes responses to powerful one-time incidents, such as accidents, natural disasters, crimes, surgeries, deaths, and other violent events. It also includes responses to chronic or repetitive experiences, such as child abuse, neglect, combat, urban violence, concentration camp experience, battering relationships, and enduring deprivation.6(p60)

Trauma produces an autonomic sympathetic discharge with initial symptoms that may include increases in heart rate, respiration, sweating, muscle tension, and vigilance, as well as overwhelming anxiety. These acute symptoms can become chronic. In PTSD, hyperarousal takes the form of acts of sudden irritability or explosive speech, often without provocation. Victims may also have trouble concentrating or may experience poor short-term memory as a result of terrifying flashbacks or nightmares. In this study, we highlight the importance of nonverbal cues in observer-assessed Type A behavior in PTSD. On the basis of clinical impressions, we recognize that PTSD patients also may show tight facial musculature, become hyperalert, and have exaggerated startle reflexes and explosive speech. The Type A behavior pattern (TABP), marked by impatience, aggressiveness, and competitiveness, can be identified and measured in different ways7-9 and has been shown to be remarkably stable from adolescence to adulthood.10,11

In the majority of studies with young people, the TABP has been associated with enhanced cardiovascular responses to cognitive tasks,12,13 physical challenges,14 and competitive situations.15

Type A individuals show more pronounced hemodynamic responses when they sense a threat of failing or of losing control.16 Although the literature on cardiovascular responses to challenges in Type A children, adolescents, and adults is inconsistent, pronounced systolic blood pressure (SBP) responses are commonly observed.4,17

Among adult Type A men, Manuck and associates'8 found greater SBP and diastolic blood pressure (DBP) variability on ambulatory measures obtained during the workday than among Type B men. Although a great deal of research on the coronary reactivity of Type A individuals has been conducted, only a few studies focused on PTSD. With several measures available for classifying Type A behavior,9 we chose to use an observer-assessed Type A measure that has been shown to be a reliable method in different studies.1-3

Studies about psychophysiological and self-reported fear reactivity to psychosocial signals that might be reminiscent of experienced trauma and impaired short-term memory and general intelligence in Type A PTSD patients are rare. In this study, our first aim was to measure observer-assessed Type A behavior and factors that would predict Type A scores and the severity of the PTSD. Our second aim was to identify those subgroups of patients, in terms of the severity and duration of their disease, who performed most poorly on the memory test and showed the highest Type A scores. Our final aim was to determine whether the patients' impaired short- term memory would have any relation to their expressed difficulties with reading and writing and to clarify associations between the Type A behavior and the CAPS (clinician-assessed interview for PTSD)17 subjective distress.

METHODS

Sample

We recruited patients with PTSD who had been referred by clinicians from a trauma clinic and healthy controls with the same ethnic background from language classes for refugees. Participants were 23 male patients (age: M = 38.65 years, SD = 6.23 years) and 17 healthy male controls (age: M = 37.88 years, SD = 8.58 years) of Iraqi and Kurdish origin who had recently resettled in Sweden. After we explained the study procedures, all participants provided informed consent on forms approved by the Karolinska Institute Ethic Committee. An experienced clinician used the CAPS18 to examine diagnostic criteria for PTSD. We used the Harvard Trauma Questionnaire19 to assess traumatic experiences and the General Health Questionnaire20 to assess participants' general health.

We recruited the control participants in the study on the basis of their being from the same ethnic group as the PTSD participants and of being in a similar stage of the migration process (ie, recently resettled). We asked those who considered themselves healthy to register for participation as controls. We offered them a small reimbursement for participating. The same clinician screened all control participants for PTSD and assessed the PTSD participants. Control participants were also assessed using the CAPS interview.

Demographic \Data

We recorded number of years of education, level of alcohol consumption, and use of medication or other drugs (see the results section).

Statistical Analysis

We tested the distribution of all continuous variables. To use parametric analysis, we required a normal distribution with skewness and kurtosis ≤ 1. We used 2-tailed statistical tests throughout and required a minimum significance level of p < .05. We used 1-way analysis of variance (ANOVA), Pearson bivariate and partial correlations, and linear regression analysis to develop models containing noncollinear variables that best predicted a number of defined endpoints.

Data Analysis

Data analyses were blind-that is, the assessor did not know whether the participant belonged to the patient category or the control group. The analysis of a given test variable was performed without any reference to other test variables by the behavioral research expert who conducted data analysis. The expert calculated changes in fear related to the magnetic resonance imaging (MRI) environment as "relief after exposure to the MRI environment" minus "fear before the MRI investigation." Reactivity was calculated as "measurements after the MRI exposure" minus "measurements before the MRI exposure."

Data Collection

We used the standard published instructions to administer and score the tests. The nonverbal memory tests were first administered in 2000 and completed in 2003. Candidates were screened with medical and psychiatric interviews and a physical examination. At 1 PM, a clinician performed the MRI of the brain structures, which took 1 hour. The postMRI measurement of blood pressure and the subjective fear in the MRI environment was performed immediately before the MRI investigation and after the participant was removed from the MRI camera and had taken about 7 steps into the next room, where he sat in a semireclining position.

Blood Pressure Measurement

An expert measured blood pressure during the same day at 10:00 AM, 12:30 PM, and 2:00 PM outside the MRI area immediately before and again immediately after the MRI investigation. He used a standard-sized, calibrated aneroid sphygmomanometer blood pressure cuff to measure pressure in the left arm. Disappearance of Korotkoff sounds indicated diastolic blood pressure. None of the men in either group was so obese (upper arm circumference > 40 cm) as to require an oversized cuff. The participants were seated in a dimly lit, quiet room where they were in semireclining positions in a comfortable armchair with head support. The room temperature was between 18 and 21C. They had eaten a light meal before the measurement, had not smoked or consumed coffee or caffeinated beverages, and had slept normally the previous night.

Self-reported Fear of MRI Exposure

Participants were asked to respond to the following:

Statement: 1.1 was afraid before exposure to the MRI.

Response: (1) No (2) Yes

Statement: 2.1 was afraid during the first half of the MRI investigation.

Response: (1) No (2) Yes

Statement: 3. I was afraid during the second half of the MRI investigation.

Response: (1) No (2) Yes

Statement: 4. In general, I was afraid during the exposure.

Response: (1) No (2) Yes

Statement: 5.1 felt relief after the exposure.

Response: (1) No (2) Yes

Statement: 6. In general, did you feel comfortable during the MRI exposure?

Response: () No (2) Yes

We used the following questions to assess "Difficulties with concentration,""Difficulties with reading and writing," and "Difficulties to sit without moving" in both the PTSD and the control groups:

Question 1: Do you generally have difficulties with concentration?

Response: (1) No (2) Yes

Question 2: Do you generally have difficulties with reading and writing?

Response: (1) No (2) Yes

Question 3: Do you generally have difficulties to sit without moving?

Response: (1) No (2) Yes

Inclusion and Exclusion Criteria

In the control and PTSD groups, we excluded men with a lifetime history of major medical or psychiatric diagnoses (eg, schizophrenia, bipolar disorder, mental retardation, organic brain syndrome, obsessive-compulsive disorder, head trauma with loss of consciousness, seizures, neurological disorder, and standard MRI exclusion criteria). We also excluded patients with histories of substance or alcohol dependence and did not include any participant with a distant history of alcohol abuse.

Ethics

We conducted the study at the Karolinska Institute and the National Institute for Psychosocial Medicine (IPM) in Stockholm, Sweden. After a researcher explained study procedures, all participants provided informed consent on forms approved by the institute's Ethic Committee.

Test Administration and Scoring

Block design test

The block design test21 asks participants to match colored cubes with patterns on a card. The test, which measures abstract intelligence more than it measures manual dexterity, is considered a standardized measure of intelligence that has been associated with integrity of frontal lobe, posteroparietal regions, particularly those involving the right cerebral hemisphere.22 The test appears to require visuospatial processing in the form of translation, rotation, or other transformations of visual mental images.

The Benton Visual Retention Test (BVRT)

The BVRT has a standard criterion for scoring23-25 to assess short-term visual memory for graphic designs. We administered forms C, D, and E 4 times and varied exposure time. We used administration D, which provides an interval between the encoding process and completing the drawing. The examinee must retain the image for a brief time. Ten cards, each consisting of 1 or more simple geometric designs, are exposed for 10 seconds; 15 seconds after the image is removed, the participant draws what he saw. The researcher records a score for the number of errors and notes the classifications and type of each. The specific types of errors are grouped into 6 major categories-(1) omissions, (2) distortions, (3) perseverations, (4) rotations, (5) misplacements, and (6) size of errors.

BVRT interrater reliability

Interscorer agreement on BVRT total scores is very high. In a study of a large sample of normal, elderly examinees, Swan and associates26 found interrater reliability coefficients of .98 and .97 for the total number error score and number correct score, respectively. In our study, a behavioral researcher expert in the field analyzed the data. To assess the reliability of his scoring, he randomly chose 4 variables for scoring by another investigator, who used the SPSS (Statistical Package for the Social Sciences, version 13.0 for Windows, Chicago, IL, 2004)27 program to calculate the intraclass reliability and assess agreement between these 2 investigators.

Thurstone 's Picture Memory Test (TPMT)

The TPMT calls for recognition by memory of 28 drawings of common items, such as a truck and a table,28 and people. Respondents are shown each picture for 5 seconds, with the response untimed, then use a recognition paradigm to assess immediate and delayed visual memory. After they have seen all scenes, the participants are asked to recall each scene and identify 1 figure among the 4 that is different. It is a measure of visual learning, figure logic, and memory.

Observe-assessed Type A behavior

During the initial contact with the participant, 2 expert behavioral researchers, one of whom was a physician, assessed 3 major coronary-prone characteristics (hyperalertness, tight facial musculature, and explosive speech). They rated each of the 3 major coronary-prone characteristics on a scale from 1 to 5 and summed the ratings for the Type A observed score.1-3 The experts who performed the assessments were blind to the participant's clinical and occupational status.

RESULTS

Intraclass reliability showed significant agreement between the 2 investigators. Results of interscorer agreement in the patient group for the total scores on the observed Type A characteristics were as follows: "explosive speech," r = .91, p = .0001; "tight facial musculature," r = .87, p = .0009; "hyperalertness, r = .85, p = .002. Interscorer agreement for the total scores on the observed Type A in the control group was as follows: "explosive speech," r = .89, p = .001 ; "tight facial musculature," r = .77, p = .01; and "hyperalertness," r = .72, p = .02.

We used 1 -way ANOVA for total observed Type A characteristics and found a significant difference between the 2 groups; the total Type A score for the PTSD patients was M = 10.90, SD = 1.79 and for the controls was M = 9.10, SD = .55, F(1, 40) = 18.95, p < .001. There were also significant differences between the PTSD and control groups on the following variables: "Explosive speech," PTSD patients: M = 3.53, SD = .94; control group: M = 2.95, SD = .22, F(1, 40) = 5.88, p < .01; "tight facial musculature," PTSD patients: M = 3.80, SD = .81 ; control group: M = 3.10, SD = .81, F(1, 40) = 13.70, p < .001; "hyperalertness," PTSD patients: M = 3.57, SD - .82; control group: M = 3.05, SD .39, F(1, 40) = 6.89, p < .01.

Tables 1 and 2 show the data on behavioral characteristics, where significant between-group differences can be seen in "Type A scores" and "subjective, self-reported reactivity to the MRI environment." Table 3 shows the specific types of errors in BVRT for successive months with PTSD for the PTSD group, and Table 4 shows these errors for severity of PTSD.

We found a significant positive correlation in the PTSD group between the "Type A behavior index" and "CAPS subjective distress," controlling for number of years of education, medication and drugs, and alcohol consumption (r = .43, ρ = .05). In addition, we found a significant positive correlation between "changes in subjective fear in relation to the MRI environment" and Type A behavior, controlling for number of years of education, smoking, and alcohol consumption, in the PTSD group (r = .43, p = .04), and a significant po\sitive correlation between "being afraid during the MRI investigation" and the Type A behavior index in the PTSD group (r = .43, p = .003).

Our analyses revealed a significant negative correlation between TPMT and Type A behavior in the PTSD group (r = -.37, p = .05), and a significant positive correlation, controlling for number of years of education, between difficulties with reading and writing and BVRT in the PTSD group (r = .53, p = .006).

We performed the following regression models, controlling for collinearity, to assess the variables that, independent of each other, would explain changes in the Type A behavior index in the PTSD group. Number of years of education, age, alcohol consumption, smoking, BVRT, and sum of error categories were incorporated in a model, but those variables were not significant, except that BVRT and sum of error categories predicted Type A behavior in the PTSD group, β = .03; t = 2.74, F(5, 23) = .40, p < .001. We incorporated number of years of education, age, alcohol consumption, smoking, and the TPMT in a model and found that TPMT predicted Type A behavior in the PTSD group, β = -.10; t = -3.13, F(5, 23) = .43, p < .001; however, none of the other variables was significant. We incorporated number of years of education, age, alcohol consumption, smoking, and the Block Design Test in a model and found that whereas the Block Design Test predicted Type A behavior in the PTSD group, β = -.04; t = -2.29, F(5, 23) = .43, p < .01 (see Figure 1), none of the other variables was significant. We also incorporated number of years of education, age, alcohol consumption, smoking, and "difficulties with concentration" in a model and found "difficulties with concentration" predicted Type A behavior in the PTSD group, β = 1.74; t= 3.28, F(5, 23) = .41, p < .001, but none of the other variables was significant.

TABLE 1. Observed Type A Scores; Subjective, Self-reported Reactivity to the MRI Environment; and Systolic and Diastolic Blood Pressure Reactivity to the MRI Environment for Successive Months With PTSD

TABLE 2. Observed Type A Scores; Subjective, Self-reported Reactivity to the MRI Environment; and Systolic and Diastolic Blood Pressure Reactivity to the MRI Environment for Severity of PTSD

In a regression model, "distortion" as an error category in the BVRT, β = 1.43; t = 3.13, F(5, 23) = .40, p < .01, and "difficulties to sit without moving,"β = 10.71; t = 2.82, F(5, 23) = .64, p < .01, independent of each other, predicted "CAPS total severity of the D criteria" in the PTSD group. We included "high school education" in the model, but it was not significant.

COMMENT

To investigate the multidimensional complexity of the hidden toll of cognitive and emotional aspects of chronic stress experience on the PTSD patients' Type A behavior, we had to apply different measurement methods to establish a countermeasure for the problem of bias in data collection. We considered the participants' self- report in reaction to the MRI environment, which could be reminiscent of the past traumatic experience, as a criterion validity (ie, the measure consistent with what is already known and what is expected) for blood pressure. Although 2 investigators assessed the Type A behavior and the interrater reliability was considered to be high between them, the self-reported fear reactions to the MRI environment could be considered a criterion validity for the Type A behavior assessment.

Our findings showed a significant difference between the 2 groups in regard to the total observed Type A behavior. In addition, there were significant differences between the groups with respect to "explosive speech,""tight facial musculature," and "hyperalertness." Psychological and physical trauma or both may produce endogenous opioid peptides, which have anxiolytic action and reduce aggression and feelings of inadequacy.

Thus, reexposure to the traumatic event or a similar situation may produce an endogenous opioid peptide response, which results in a subjective sense of calmness or control. This might explain why some patients with PTSD continually seek out situations that remind them of the traumatic event, which, in turn, could contribute to the Type A behavior. When the traumatic stimulus stops, a subsequent reduction in endogenous opiates may occur, creating symptoms that mimic opiate withdrawal. These symptoms are probably mediated by central nervous system noradrenergic hyperactivity and include anxiety, irritability, hyperalertness, and Type A behavior.

Suis29 describes a connection between denial and a specific subtype of Type A behavior (ie, hyperarousal and explosive speech) that we used in this study. According to Suis, who based his description on his review of the literature, only this subtype of Type A behavior is actually coronary-prone.

Our findings on the subjective reactions of the sampled patients to the MRI environment, which could remind them of the trauma they had experienced, showed that this patient group does not deny the unpleasant emotional consequence of exposure to the MRI investigation. Researchers have reported that systematic failure to monitor the external and internal milieu or "chronic cognitive or behavioral avoidance" has been associated with negative physical health consequences.29,30 Roth and Cohen30 and Suis and Fletcher31 have described scenarios of high-risk response patterns (eg, lack of self-awareness leading to overexertion in the face of a challenging situation) that lead to physiological hyperactivity that can, inter alia, promote atherosclerosis.

Tables 1 and 2 show behavioral data, observed Type A scores, "subjective, self-reported reactivity to the MRI environment" and "systolic and diastolic blood pressure reactivity to the MRI environment" for successive months with PTSD and for severity of PTSD. Severe PTSD may promote poor health through a complex interaction between biological and psychological mechanisms. Chronic suppressed fear is a possible mediator of the relationship between severity and duration of PTSD, and physical health is commonly associated with PTSD. Decades of research on the health risks associated with the Type A behavior pattern have isolated fear as a crucial factor in cardiovascular disease.

PTSD and poor health also may be partially mediated by behavioral risk factors for disease, such as smoking, substance abuse, diet, and lack of exercise. In this study, we found no significant difference between the PTSD and control groups in alcohol consumption, medication or other drugs, and number of years of education. The participants in the PTSD group, as well as those in the control group, had recently settled in Sweden, and many of the men in the control group were waiting for permission to stay there.

An overwhelming life event in a normal individual results in activation of the sympatho-adrenal system that causes a rise in noradrenaline and adrenaline, stimulation of the thyroid system that causes increased secretion of thyroid hormones, and activation of the hypothalamic-pituitary-adrenocortical (HPA) system, resulting in elevated levels of cortisol. Wang's32 studies in animals and humans with PTSD indicate that chronic traumatic stress can result in dissociation of the sympatho-adrenal medullary and HPA system, resulting in sustained elevations of the sympathoadrenal medullary but suppressed or altered ACTH-corticoid responsivity.

Our findings show a regression model in which "distortion" as an error category in the BVRT and "difficulties to sit without moving," independent of each other, predicted "CAPS total severity of D criteria" in the PTSD group. Symptoms included in the D (hyperarousal) criterion most closely resemble those seen in panic and generalized anxiety disorder. The hypervigilance in PTSD may sometimes become so intense that it appears to be frank paranoia.

In previous research,33 "distortion" accounted for 21% of all errors made by this PTSD group. The medial temporal lobe may function to bind together processed information from frontal and other cortical regions to form lasting memory traces that can be recalled. Thus, both regions would be critical to the conception of a short-term memory, and lack of participation of either brain region would disrupt memory formation. A consequence of this hypothesis is that activity within the frontal cortex should fail to introduce by gradual, persistent efforts to form a memory if the medial temporal lobes are dysfunctional. Indeed, this prediction is upheld by recent findings. Performance in tasks that require optimal concentration and executive control relies on a cortico-subthalamic interaction within the neural circuitry of the basal ganglia.

TABLE 3. Mean Scores of 6 Error Categories of the Benton Visual Retention Test for Severity of PTSD

TABLE 4. Mean Scores of 6 Error Categories of the Benton Visual Retention Test for Duration of PTSD

"Difficulties to sit without moving" is an official criterion for acute stress disorder. It includes significant symptoms of anxiety or arousal (eg, difficulty sleeping, feeling irritable, poor concentration, hypervigilance, being easily startled, feeling restless or unable to sit without moving). Many PTSD patients can selectively attend to some stimuli but not to others. These patients attend to everything in the environment, which results in the tendency to wander around the room: They simply cannot sit without moving.

When an individual experiences a severe sense of helplessness, his gonadotrophins are diminished and the selfpreservative fight- flight catecholamine coping response takes priority. Stress experience of long duration after the traumatic event that has been severe enough to create a dissociative effect, disrupting right hemispheric emotional functioning, preservative behavior, and a permanent bias toward self-preservation can become the actual trait. In these patients, cor\ticoid responses may be deficient. The TABP seen in these patients might exhibit some of this deficiency in preservative reactivity against relevant symbolic psychosocial signals.

The TABP has been defined as an action-emotion complex involving specific behaviors, such as muscle tenseness, heightened alertness, rapid and emphatic speech, and fast pace of performed activities, plus emotional responses, such as hostility, irritation, and augmented potential for anger.34,35 Harassing, reaction time elicits significantly greater systolic blood pressure, heart rate, and catecholamine levels in men with TABP compared with those without this pattern.36-38

We found a significant positive correlation in the PTSD group between "TABP index" and "CAPS subjective distress," when controlled for number of years of education, medication and drugs, and alcohol consumption. We also noted a significant positive correlation between "Changes in subjective fear in relation to the MRI environment" and the Type A behavior. Booth-Kewley and Friedman39 and Friedman and associates40 used meta-analysis to organize the literature findings concerning psychosocial variables and coronary heart disease (CHD). They found the strongest associations to be with TABP, particularly in cross- sectional studies.

Coronary-prone behavior as assessed by the present method has also been found to be significantly higher among professional drivers than employed referents.1-3 There was a significant positive correlation between "being afraid during the MRI investigation" and the Type A behavior index in the PTSD group. In the Western Collaborative Group Study, Brand and associates41 reported that TABP made an independent contribution to risk of coronary heart disease in 2,154 healthy middle-aged men in 12-year follow-up studies.

It is suggested that Type A individuals who suffer from CHD have passed through a state of frustration and exhaustion before they experience their myocardial infarction.42(p614) The traumatic experience can be considered the prototype for provoking Type A behavior. The interrelations among stress factors, behavioral patterns of responding to these stressors, and poor performance on intelligence and memory tests, together with self-reported hyperarousal and blood pressure reactions to environmental stimuli reminiscent of the trauma, might be contributing factors to the TABP in these PTSD patients.

Our findings in this study, together with findings in previous studies with regard to (1) high anxiety that fails to disappear in response to the novel, relevant stimuli;43 (2) decreased hippocampus volume;44 (3) impairment in the figure logic;45 (4) learning problems in relation to severity and duration of disease;46 (5) impairment in nonverbal memory in these refugees with PTSD compared with the refugees without PTSD, accounting for executive functions, age, and education;33 and (6) impaired spatial and visuoconstructional abilities, suggest that these patients suffer from central incoherence (R. Emdad and H. P. Sndergaard, unpublished data; 2005).

PTSD patients' experiences have been that potential danger is always present. That means that the filing system in their brains is stored with memories that indicate that even seemingly benign situations can carry some hidden threat. When people are responding to the environment out of fear of a potential threat, they become hypervigilant, their heart rate is often higher than normal, even at rest, and their adrenalin system is always pumped up and ready for "fight or flight."

This fight-or-flight phenomenon is evident in patients who are often defensive, ready to blame themselves and others, in need of controlling each situation they encounter, ready to fight back when there is nothing to fight about, and seem to "check out" and become nonresponsive to any requests. People who are suffering from some form of PTSD or traumatic stress are both emotionally and neurophysiologically "alert" to potential danger. Experience with trauma and highly emotional situations filled up their filing system. The MRI environment is likely to repeat the traumatic situation emotionally, but because the traumatized individual functions at a higher adrenalin level, the new emotional experience is likely to be highly charged.

The data in Table 3 show the specific types of errors in the BVRT for months with PTSD in the PTSD group; Table 4 shows these errors for severity of PTSD. We found a significant negative correlation between TPMT and the Type A behavior in the PTSD group. In one regression model, the TPMT predicted Type A behavior in the PTSD group, and in another regression model, the block design test predicted Type A behavior in these patients (see Figure 1). A subgroup of PTSD patients with 21 to 100 months' PTSD duration and those with the highest severity of the disease performed most poorly on the BVRT (different error categories). They also showed the highest scores on the self-reported subjective reactivity to the MRI environment.

FIGURE 1. Type A behavior scores in the posttraumatic stress disorder (PTSD) and control groups.

As an anxiety disorder, PTSD has its foundations in fear and emotional memory. Like factual memory, emotional memory also involves storage and recall of events and details; this has been termed the explicit or conscious memory. Emotional memory, though, has a second, distinct component. This facet, the implicit or unconscious memory, is the memory of the physiological response, such as increased blood pressure, a higher respiratory rate, and muscle tensing, and is responsible for the emotional impairment that PTSD causes.

In previous research,33 we found a significant difference between this PTSD group and the control group in the BVRT sum of incorrect responses. In the study we report here, the results of the BVRT were found to be a significant predictor of Type A behavior, independent of alcohol consumption, smoking, and number of years of education. The PTSD group showed marked exacerbation of their shortterm memory function and significantly higher Type A scores compared with the control group, members of which had the same ethnic background.

Thus, the cognitive implications of damage to the hippocampus in PTSD44 are an impairment of episodic memory and novelty detection that gives rise to Type A behavior, a fear reaction accompanied by blood pressure reactivity4 and poor performance in BVRT. The hippocampus signals novelty in its role in episodic memory; it also acts as a warning system for behavior when significant mismatches occur between expectations and reality. "Difficulties with concentration" predicted Type A behavior, and in another regression model, the sum of error categories in the BVRT predicted Type A behavior in the PTSD group. We also found a significant positive correlation between "difficulties with reading and writing" and BVRT in the PTSD group. After a traumatic experience, the human system of selfpreservation can go on permanent alert, as if the danger may return at any time.47

Hypervigilance, experienced as "hyperalertness," is an acute state of vigilance (sensitivity and awareness of one's surroundings). Sleep disorders, evident in trouble falling asleep, frequent awakening, early-morning awakening, and nightmares, are also common. Most survivors experience such problems immediately after the traumatic incident. For some, these problems persist for months, accompanied by short-term memory problems and learning difficulties. One could presume that the intelligence tests, short- term memory tests, Type A behavior scores, and fear reactions to the MRI environment connect these results with neurological damage, but in light of more recent experimental data, these results seem to be correct. Van der KoIk and McFarlane48 explain that people with PTSD have decreased hippocampus volumes, compared with matched controls. The previous experience of overwhelming stress experience and preexisting traumatization might lead to different degrees of posttraumatic stress disorder and affect the cardiovascular system, brain morphology, and cognition.49

The hippocampus is needed temporarily to bind together distributed sites in the neocortex that together represent a whole memory.50(p108) In animal models, neurons in the hippocampus and prefrontal cortex respond to repeated stress by showing atrophy, whereas neurons in amygdala show a growth response. Yet, these are not necessarily damaged and may be treatable with the right medications.51 It is possible that after an organism successfully resists a nonchronic demand and returns to baseline, there will be no apparent damage or permanent harm caused by the demand. But, when demands are experienced repeatedly, the organism may develop harmful consequences, even though nonspecific responses have returned to baseline after each demand occurs.51(p191) In other words, the continued reliving of a traumatic experience constitutes a prolonged stressful situation. That PTSD sufferers continuously focus on the event or events that precipitated the PTSD confirms the assertion that stress hormones are elevated in their brains. This, in turn, affects the brain structures.

CONCLUSION

Our findings in this study concerning the severity and duration of the PTSD indicated that patients with PTSD are neurophysiologically "alert" to potential danger. Suppressed fear is a possible mediator of the relationship between severity and duration of PTSD and the observed Type A behavior in these patients. The interrelations among stress factors, behavioral patterns of responding to these stressors, poor performance on intelligence and memory tests, together with hyperaroused, self-reported, and blood pressure reactions to the environmental stimuli, might be contributing factors to the Type A behavior in these PTSD patients. Decades of research on the health risks associated with the Type A behavior pattern have i\solated fear as a crucial factor in cardiovascular disease.

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Reza Emdad, PhD; Hans Peter Sndergaard, MD, PhD

Dr Emdad is with the Karolinska Institute and the National Institute for Psychosocial Medicine (IPM) in Stockholm, Sweden; Dr Sondergaard is with the National Institute for Psychosocial Medicine and Trauma Clinic, Danderyds Hospital, Stockholm.

NOTE

For comment or further information, please address correspondence to Reza Emdad, PhD, Karolinska Institute and the National Institute for Psychosocial Medicine, Box 230, S-17177 Stockholm, Sweden (e- mail: Reza.emdad@ipm.ki.se).

Copyright HELDREF PUBLICATIONS Summer 2005

Source: Behavioral Medicine

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