Emotional Processing and Outcome of Imaginal Flooding Therapy in Vietnam Veterans With Chronic Posttraumatic

Stress Disorder

Roger K. Pitman, Scott P. Orr, Bruce Altman, Ronald E. Longpre, Roger E. Poir6, Michael L. Macklin, Michael J. Michaels, and Gail S, Steketee

This sludy examined emotional processing and out- come in 20 Vietnam veterans with chronic posttrau- matic Stress disorder (PTSD) who underwent imaginal f lood ing therapy. Results supported the occurrence of emotic~nal processing, as manifest in significant activa- tion, Within-session habituation, and partial across- sessiofi habituation of physiologic and self-reported process variables. The flooding therapy produced only modest overall improvement, which was statistically significant for avoidance symptomatology measured by the Impact of Events Scale (IOES) and number of intrusions per day recorded by the subject in a log.

Symptomatic improvement appeared to generalize f rom a treated to an untreated experience. Heart rate activation during the first flooding session predicted a decrease in daily number of intrusive combat memo- ries across the therapy. Otherwise, there was l i t t le association between extent of emotional processing and therapeutic outcome. The results provide limited support for the notion that mobilization of psycho- physiologic arousal during exposure therapy predicts improvement. Copyright © 1996 by W.B. Saunders Company

D IRECT THERAPEUTIC exposure has been defined as "repeated or extended

exposure, either in reality or in fantasy, to objectively harmless, but feared, stimuli for the purpose of reducing negative affect. ''1 (p. 3) Foa and Kozak 2 have offered a model of improve- ment during exposure therapy based on the concept of emotional processing. Lang 3 ob- served that processing of conceptual emotional information always involves some degree of visceral and motor outflow, implying that psycho- physiology may be useful in tracking its course. Foa and Kozak propose that successful process- ing of pathologic fear requires activation of the fear structure, followed by modification of this structure through incorporation of corrective information. They identify a set of changes held to occur during the course of treatment of subjects who improve with exposure treatment that serve as indicators of successful emotional processing. These include physiologic responses and self-reports that indicate activation of emo- tion during exposure, a gradual reduction (ha- bituation) of the magnitudes of these reactions within exposure sessions, and a reduction of the magnitudes of these reactions across exposure sessions. Psychophysiologic and self-reported process measures obtained during imaginal and in vivo exposure therapy of subjects with obses- sive-compulsive disorder (OCD) supported this formulation. 4

Posttraumatic stress disorder (PTSD) may be particularly suitable for treatment by imaginal exposure (or flooding) because a past event that

cannot be readily recreated in reality underlies the disorder. 5 Earlier case reports 6-11 and later controlled studies, 12-16 a number of which used combat veteran subjects, have reported positive therapeutic results with imaginal exposure in PTSD.

In anecdotal case vignettes taken from six PTSD Vietnam veterans treated within the study of imaginal flooding of combat-related PTSD reported herein, we described untoward complications, including exacerbation of depres- sion, relapse of alcoholism, and precipitation of panic disorder. 17 We suggested that a feature of several of these complications appeared to be mobilization or exacerbation of a negative self- appraisal of the person's actions or inactions in the traumatic situation, accompanied by guilt and shame. We speculated that these emotions may not obey the same law of extinction as does anxiety on which the rationale for exposure therapy is based.

To our knowledge, the emotional processing model of therapeutic improvement during expo-

From the Veterans Affairs Medical Center, Manchester, NH; Department of Psychiatry, Harvard Medical School, Boston, MA; Cornell University Medical College, New York, IVE," and School of Social Work, Boston University, Boston, MA.

Supported by National Institutes of Mental Health Grant No. RO1MH42872 and a Veterans' Affairs Research Career Development Award ( R.IC P. ).

Address reprint requests to Dr. Roger K. Pitman, VA Research Service, 228 Maple St, Manchester, Ni l 03103.

Copyright © 1996 by W.B. Saunders Company 0010-440X/96/3706-0007503.00/0

Comprehensive Psychiatry, Vol. 37, No. 6 (November/December), 1996: pp 409-418 409

410 PITMAN ET AL

sure therapy 2 has no t b e e n quant i ta t ively tested

in PTSD. This constituted the goal of the present study. We hypothesized that (1) PTSD subjects

undergoing imaginal flooding therapy would show evidence of emotional processing in the form of activation, within-session habituation, and across- session habituation of physiologic and self-report measures of negative emotions; (2) subjects would show improvement with imaginal flooding, mani-

fest in decreased levels of PTSD symptoms indexed

by several outcome measures; and (3) the extent of each of the three dimensions of emotional process-

ing would predict the amount of improvement. Because of its capability of measuring PTSD intru-

sion and avoidance symptomatology associated with

a specific combat-related event that constituted the object of treatment, a priori emphasis was given to the Impact of Event Scale in assessing outcome of flooding therapy.

Subsequen t to the per formance of the study, bu t before data analysis, we formula ted addi- tional hypotheses that were based on clinical impres-

sions during the course of the study's performance,

reflected in our previous report on complications of flooding. 17 We hypothesized that activation of nega-

tive emotions other than fear, specifically anger and guilt (shame, unfortunately, was not measured),

would predict a negative outcome, and that these emot ions would not show the within- or across-session hab i tua t ion expected for fear.

M E T H O D

Subjects Subjects were 20 male Vietnam combat veterans meeting

diagnostic criteria for PTSD as determined by the Struc- tured Clinical Interview for DSM-III-R (SCID). m To partici- pate, each subject had to describe two combat-related events he considered to have been emotionally traumatic and implicated in his subsequent symptoms. Subjects were recruited as part of an outreach effort and were not necessarily seeking treatment for their PTSD. Inpatients were excluded, as were subjects with an organic, psychotic, manic, or melancholic disorder, or with current alcohol or other substance dependence. Subjects enrolled in other individual or group psychotherapy were allowed to enter the study only if the concurrent therapy was supportive in nature and was not expected to overlap or conflict with the research therapy. Subjects who were on medication, includ- ing psychotropic medication or substances that could inter- fere with the physiologic responses to be measured, were asked to abstain from its use for a month prior to and for the duration of the study. Subjects in whom this was medically contraindicated or who were unwilling to meet this require- ment were excluded.

Subject demographic and psychometric measures (mean -+ SD) were as follows: age, 42.5 _+ 2.7, educational level (i.e., highest grade completed), 14.8 _+ 2.0, and combat exposure, 11.6 -+ 2.8 (on a 0-14 scale)J 9 Current comorbid axis I disorders included six (30%) major depression, three (15%) dysthymia, four (20%) panic without agoraphobia, two (10%) social phobia, two (10%) simple phobia, two (10%) generalized anxiety, one (5%) obsessive compulsive, one (5%) somatoform, and one (5%) alcohol abuse. Some subjects had more than one comorbid disorder; six (30%) had none.

All subjects were enrolled as Veterans Affairs (VA) Medical Center outpatients and were aware that their progress would be documented in their VA medical record. All gave written, informed consent for participation after the nature of the procedure and the risks and potential benefits had been disclosed to them.

Flooding Therapy One week prior to the first therapy session, a preparatory

session was devoted to rapport building between subject and therapist and training the subject in relaxation and pleasant imagery techniques. Therapy was performed ac- cording to a PTSD Flooding Therapy Manual (available on request) based on a published procedure z° modified for the purposes of the present study. So-called "hypothesized cues," i,e., cues representing the therapist's speculations regarding components of the event not reported by the patient, were not used.

The therapists were four doctoral-level, behaviorally trained therapists (authors B.A., R.E.L., R.E.P., and Dr. Evan Greenwald). The same therapist treated a subject throughout his participation. The therapists received spe- cial training and practice in implementing the therapy from an expert in the field (G.S.S.).

The expert rated videotapes of approximately one third of the flooding sessions for therapy integrity according to a score sheet (available on request) that used a 0 to 6 scale, with 0 indicating "unacceptable," 1 indicating "marginally acceptable," and 2 to 6 indicating "acceptable" in increas- ing degrees. Completed score sheets and suggestions for improving the therapy were fed back to therapists as therapy progressed.

A first (designated "A") series of six weekly flooding sessions focused on one of the subject's two reported personal traumatic combat events, selected at random. A second ("B") series of six weekly flooding sessions focused on the other reported personal traumatic combat event. The event that served as the focus of a given flooding series is referred to hereinafter as the "treated" (trt) event; the remaining event as the "untreated" (untrt) event.

Therapy Process Variables Physiologic process variables consisted of heart rate

(HR), skin conductance (SC), left lateral frontalis electro- myogram (EMG-frnt), and left corrugator EMG (EMG- corr), which were obtained according to instrumentation and techniques described elsewhere. 21,22 A behavioral pro- cess variable was derived from the number of total body movements during a given 10-minute segment, scored by

EMOTIONAL PROCESSING DURING FLOODING IN PTSD 411

M.J.M. according to a published technique. 23 Self-report process variables consisted of arousal, sadness, anger, fear, and guilt, all rated by the subject via joystick on 0 to 12 Likert-type scales displayed on a monitor in the subject r o o m .

Procedure

Flooding sessions were held in the psychophysiology laboratory. On arrival, the technician had the subject empty his bladder and made him comfortable in a reclining chair in a dimly lit, sound-attenuated, temperature-controlled room adjacent to the laboratory housing the recording equip- ment. During the first and last session of each flooding series, the technician placed a sterile catheter into an antecubital or large hand vein, which was attached to extension tubing passing through a small hole into the adjacent laboratory, where the technician could unobtru- sively draw blood specimens over the course of the session (data to be reported elsewhere). The technician then attached the physiologic recording electrodes. Subjects generally reported that they readily disregarded the pres- ence of the catheter and electrodes as the flooding com- menced and did not notice blood being drawn.

Each session began with 10 minutes of baseline physi- ologic recording followed by 10 minutes of relaxation and pleasant imagery. The flooding was initiated by the thera- pist's reading the subject a brief (30 second) description of the combat event selected for treatment. There ensued seven to 11 10-minute flooding segments. If at the end of the seventh flooding segment (i.e., after 70 minutes of flooding), in the therapist's opinion a satisfactory reduction in emo- tional distress had been achieved, the session was ended. If not, up to four additional segments were provided. Each session concluded with a brief discussion with the therapist of what had transpired during the session. If a subject expressed concern that the therapy was having negative effects, he was encouraged to complete the course of flooding treatment nonetheless, in the hope of an eventual positive result.

To eliminate artifacts in the physiologic (especially facial EMG) data that might be associated with the act of talking, at minute 8 of each 10-minute flooding segment, a green light visible only to the therapist came on, warning of the impending final minute of the segment. The therapist then told the subject that for one minute that was to begin shortly, he was not to talk but should listen to the therapist and continue to imagine the event that was being flooded as it had unfolded during the preceding minutes. At minute 9, a red light came on advising the therapist of the beginning of the final minute of the segment. During this minute, only the therapist spoke, helping the subject to maintain the image of the combat event being flooded. At minute 10 of each segment, the monitor displayed the self-report scales one at a time. The therapist urged the subject to rate the emotions he was experiencing at that moment as quickly as possible, which was usually accomplished in less than 1 minute, and then immediately continued the flooding.

During the final minute of the 10-minute baseline seg- mere, relaxation segment, and ensuing 7 to eleven 10- minute flooding segments, each physiologic variable was

sampled at 2 Hz, averaged on line, and stored for subse- quent analysis.

Therapy Process Measures

Therapy process measures were calculated from the therapy process variables described previously, according to a published method. 4 For each process variable, an activa- tion (ACT) score was calculated for the first session of each flooding series by subtracting the mean score for the 10-minute relaxation segment preceding flooding from the mean score for the highest (peak) 10-minute flooding segment during the same session. Within-session habitua- tion (WSH) was calculated by subtracting the mean score for the final (end) 10-minute flooding segment from the peak segment mean score. Across-session habituation (ASH) was calculated by taking the ACT score for the first flooding session of a series minus the ACT score for the last flooding session of the same series.

Outcome Measures

Each outcome measure was obtained 1 week before the A flooding series, between the A and B flooding series (i.e., 7 weeks later), and 1 week following completion of the B flooding series (another 7 weeks later), except that SCID PTSD severity (described later) was not assessed between A and B flooding series. Outcome measures included the Impact of Events Scale (IOES), 24,25 divided into its intrusion (IOES-int) and avoidance (IOES-avd) subscales, and col- lected separately for the subject's two reported personal traumatic combat events; the Mississippi Scale for Combat- Related PTSD26; the Symptom Check List-90-Revised Glo- bal Symptom Inventory (SCL-90-R GSI)27; and the two outcome measures described below.

During the first and last assessment weeks, a psychologist experienced in PTSD psychodiagnostics, while performing the PTSD module of the SCID, rated the severity of each of the 17 DSM-III-R PTSD symptoms--plus survivor guilt--on a 0 to 7 severity scale constructed by R.K.P. for the present study (available on request). This unvalidated scale served a similar purpose to the current, validated clinician-adminis- tered PTSD scale, 28 which was not available at the time. All symptom severity scores were summed to yield an overall 0 to 126 SCID PTSD severity score.

During the first, middle, and last assessment weeks, the subject was provided with a wrist watch programmed to sound a soft alarm at 10 AM, 2 PM, 6 PM, and 10 PM on 3 successive days. Each time the alarm sounded, the subject was instructed to record on a log (available on request) the number of intrusive combat memories that had occurred during the preceding 4 hours. Average number of intrusions per day were calculated and subjected to a square-root transformation in order to reduce skewness and heterosce- dasticity.

RESULTS

Course of Treatments

Al l 20 s u b j e c t s e n t e r e d a n d c o m p l e t e d t h e

f i rs t ( A ) f l o o d i n g se r ies . F o u r t e e n s u b j e c t s e n -

t e r e d t h e s e c o n d ( B ) f l o o d i n g se r ies , a n d six d i d

412 PITMAN ET AL

not--three for nonclinical reasons (i.e., schedul- ing or availability problems) and three for clinical reasons. Among the latter, one was referred for treatment on an inpatient PTSD unit, one was terminated due to relapse of problem drinking and was referred for alcohol- ism treatment, and one declined to continue because of headaches during the flooding. The mean number of flooding sessions per subject was 10.2.

Therapy Integrity The rater (G.S.S.) found therapy integrity

acceptable for all sessions rated and assigned the therapy sessions an average overall integrity rating of 5.4 (highly acceptable, SD = 0.7) on the 0 to 6 scale.

Process Variables and Measures

Fig. 1 presents the group baseline, relaxation, peak, and end levels for HR, SC, EMG-frnt,

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E M O T I O N A L P R O C E S S I N G D U R I N G F L O O D I N G IN P T S D 4 1 3

and EMG-corr, and movements for the first and last sessions of flooding series A (= 20), and for the first and last sessions of flooding series B (n = 14). Fig. 2 presents parallel data for the self-report process variables. During the first session of the A flooding series, median peak segments for various process variables were: HR, 20 minutes; SC, 30 minutes; EMG-frnt, 30 minutes; EMG-corr, 30 minutes; arousal, 30 minutes; sadness, 20 minutes; anger, 30 min-

utes; fear, 20 minutes; and guilt, 30 minutes. Therefore, subjects appeared to experience peak emotional arousal approximately 20 to 30 min- utes after the initiation of flooding. Lengths of flooding during the first session of the A flood- ing series were 70 minutes for 15 subjects, 80 minutes for one subject, 90 minutes for three subjects, and 100 minutes for one subject.

Statistical analyses for process data consisted of paired t tests performed separately for the A

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414 PITMAN ET AL

and B flooding series. Because the hypotheses regarding process were directional, the criterion for significance for these tests was set at P < .10 (which corresponds to one-tailed P < .05). Dur- ing both A and B flooding series, significant ACT and WSH occurred for each process vari- able. During the A series, significant ASH occurred for HR, arousal, sadness, anger, and fear. During the B series, significant ASH oc- curred for HR and sadness.

Outcome Measures

Fig. 3 presents pre- and postflooding outcome data separately for series A and B. (Although the post-A and pre-B values coincided for individual subjects, slight differences in these two group means may appear because the post-A group data are averaged over 20, but the pre-B group over only 14 subjects.) Statistical analyses for outcome data consisted of paired t tests performed separately for the A and B flooding series, with the criterion for signifi- cance set at P < .10. From before to after the A flooding series, significant improvement oc- curred for IOES-avd (trt), IOES-avd (untrt), and intrusions per day. From before to after the B flooding series, significant improvement oc- curred for IOES-avd (trt). Comparisons across treated and untreated events were performed by analyses of variance for repeated measures, with the criterion for significance set at P < .05. These analyses showed that decreases in IOES- int and IOESoavd were not significantly greater for treated than untreated personal traumatic combat events--i.e., improvements in intrusion and avoidance symptomatology appeared to generalize to the unflooded combat experience.

Process-Outcome Correlations

Analyses of the relationships between pro- cess and outcome consisted of Pearson product- moment correlations between ACT, WSH, and ASH for the process variables shown in Fig. 1 and Fig. 2 versus the pre- to postflooding decreases in outcome measures shown in Fig. 3, performed across the whole study--i.e., from preseries A to postseries B for the 14 subjects who completed both flooding series, or from preseries A to postseries A for the 6 subjects who completed only flooding series A. Because of the multiple correlations in the matrix, the

criterion for significance for these correlations was set at P < .01. The only significant correla- tion was between pre- to postflooding decrease in the intrusions per day outcome measure and HR-ACT (r = .70). There was a nonsignificant trend (P < .05) for decrease in intrusions per day also to be correlated with HR-WSH (r = .51) and HR-ASH (r = .46). Otherwise, there were no consistent patterns or trends discernible in the process-outcome correlation matrix. No in- dividual process-outcome correlations involving anger-ACT or guilt-ACT approached statistical significance.

DISCUSSION

Emotional Processing

Results of this study support the occurrence of emotional processing of traumatic memories in PTSD combat veterans during the initial session of each flooding series, as manifest in significant ACT and WSH of all physiologic and self-report process variables. Partial emotional processing over the longitudinal course of the flooding sessions was evidenced by significant ASH of some, but not all, process variables. The process data appearing in Figs. 1 and 2 are similar to comparable data obtained during imaginal exposure in OCD (p. 164, Fig. 1). 4 Moreover, whereas that study produced evi- dence of WSH only for the physiologic variables used, the present study found significant WSH for all physiologic and self-report variables. Also, whereas that study produced evidence of ASH only for self-report variables, the present study found ASH for one physiologic (HR) and several self-report process variables. However, in light of the limited improvement reported by subjects in the present study, as described immediately hereinafter, the absence of signifi- cant ASH of some of the physiologic and self- report variables, and the incompleteness of this habituation even in the variables in which it achieved statistical significance (Fig. 1 and Fig. 2), may be revealing.

Therapeutic Outcome

Despite the physiologic and self-report evi- dence of emotional processing, the 13% mean pre- to posttreatment decrease in the outcome measures in Fig. 3 over the course of a mean of 10.2 imaginal flooding sessions suggests that the

EMOTIONAL PROCESSING DURING FLOODING IN PTSD 415

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Miss Scale Inst fusions/Day (sq. root) SCL-90-R GSI SCII~ PTSD Severity

Fig3. •utcome measures pre- v p•stfl••ding series A (n = 2•) and B (n =14). ••Es•int• •mpact •f Event Sca•e intrusi•n subsca•e• IOES-avd: Impact of Event Scale avoidance subscale; trt, treated combat event, untrt, untreated combat event; Miss Scale, Mississippi Scale for Combat-Related PTSD; SCL-90-R GSl Symptom Check List-90-Revised Global Symptom Inventory; Intrusions/ Day, number of intrusive combat memories per day recorded by the subject in a log; SCID, Structural Clinical Interview for DSM-III-R.

overall therapeutic benefit shown by the sub- jects in the present study was modest. Although inferences from average improvement calcula- tions are limited by the use of different outcome measures across studies, they do allow a rough comparison of outcome of flooding in the pre- sent study compared with outcome in other published flooding studies. Overall pre to post- therapy improvement over 14 to 16 sessions of implosive therapy in another study of Vietnam veterans 13 (calculated by averaging the outcome measures appearing in Figs. 1 and 2 on pp. 251-252 of that publication) was 28%. Overall pre to posttherapy improvement over nine ses- sions of prolonged exposure in a study of PTSD rape victims 16 (calculated by averaging the out- come measures appearing in Table 3 on p. 719 of that publication) was 38%.

An attempt to understand why the successful emotional processing found in the present study did not translate into more therapeutic benefit

than was observed must begin with the question of whether outcome measures accurately gauged the actual degree of subjects' improvement. Almost all the subjects in the present study were either receiving or seeking service-connected compensation. Compensation is commonly re- garded by therapists as an obstacle to successful treatment of PTSD within the VA. 29,30 Because their progress was documented in their medical records, subjects in the present study were aware that reporting improvement might result in a reduction of their service-connected com- pensation. It would not be surprising if they denied or minimized (consciously or uncon- sciously) the amount they actually improved under such a disincentive. Also, for many Viet- nam veteran patients, the entitlement conferred by PTSD diagnosis has become integrated as a component of self-image that may not be readily relinquished. The pattern of change scores observed here for the outcome measures may be

416 PITMAN ET AL

consistent with this suggestion. When subjects actually counted and recorded the number of their intrusive combat memories, they showed an average 26% reduction across the flooding sessions. However, in face-to-face interviews with a VA psychologist conducted before and after the flooding therapy, the same individuals reported an average 14% increase in PTSD severity. In a recent pharmacologic study of PTSD performed at a VA and a non-VA site, combat veteran subjects reported considerably less improvement than nonveteran subjects treated within the same protocol. 31

Factors pertaining to subjects, recruitment strategy, and treatment protocol may also have limited the actual positive therapeutic outcome in the present study. The chronicity of the disorder in subjects was approximately 20 years. Comorbidity was substantial; 70% of subjects had at least one current non-PTSD axis I disorder. We have previously reported that comorbidity increased the risk of a negative outcome of flooding in this sample. 17 A number of subjects were not treatment-seeking, but rather were enrolled by means of outreach. This is reminiscent of the Israeli "Koach" project--an ambitious outreach effort to rehabilitate iso- lated PTSD combat veterans through a month of intensive residential treatment--which in- cluded flooding as a central component. 32 After treatment, Koach participants reported an in- crease in extent and severity of their psychiatric symptomatology. 33 In the present study, before beginning treatment several subjects were with- drawn from their psychotropic medications to avoid confounding the psychophysiologic mea- surements. Discontinuation of pharmacotherapy may have induced a tendency toward relapse, against which the flooding therapy had to struggle. Moreover, unlike previous flooding studies of PTSD Vietnam veterans, 12,13 subjects in the present study were not allowed anxiolytic medication. A few subjects who expressed con- cern that therapy was having negative effects were encouraged to complete it nonetheless, in the hope of an eventual positive result. Out- come scores in these subjects may have been more negative than they would have been had the therapy been stopped earlier.

Factors pertaining to the therapy may also have limited improvement. For example, there

was no in vivo exposure. Although combat- related PTSD patients cannot be placed back into a live combat situation, practical in vivo components might include exposure to such stimuli as combat sounds, weapons, or Asian faces. Foa and Kozak have more recently ob- served that, "[I]maginal exposure to disaster scenarios may change the valence of associated events more than it changes the valence of the disaster itself...-34 (p. 35) They suggested that whereas promoting physiologic ACT and habitu- ation may be sufficient for treating simple pho- bics, it may be insufficient for OCDs, for whom treatment may also need to address the more complex meaning of the fear structure. These authors commented: "In effect, we practice informal cognitive therapy during exposure. ''34 (p. 45) In PTSD, it may be even less sufficient merely to attempt to promote physiologic ACT and habituation via exposure. Rather, it may also be necessary to include a cognitive therapy component that addresses complex, trauma- related meanings. The study reported here did not include such a component. Instead thera- pists adhered to a strict exposure model of treatment, rather than adopt broader cognitive- behavioral techniques which in retrospect might have been more therapeutic, albeit less appro- priate to the hypotheses being tested.

Unlike OCD, in which a disaster scenario only represents an irrational fantasy, in PTSD an actual disaster has usually occurred. No corrective information is available to alter this immutable fact in the psychic history of the patient. Psychoanalytic theory distinguishes be- tween traumatic (i.e., unconditioned) anxiety, which is automatic, nonspecific, and the product of having been helplessly overwhelmed in a past traumatic situation, and neurotic, signal (i.e., conditioned) anxiety, which involves the antici- pation of possible future traumatization. 35 Com- bat-related PTSD appears to involve both uncon- ditioned 36 and conditioned 37 fear components. Because a portion of the anxiety present in PTSD may not be anticipatory or conditioned in nature, it may not be amenable to modification by exposure, which aims to extinguish the link between stimuli and their anticipated negative consequences through the incorporation of cor- rective information.

EMOTIONAL PROCESSING DURING FLOODING IN PTSD 417

Process-Outcome Relationship

Given the absence of significant correlations, or even trends, between the great majority of process and outcome measures, the overall results provide little support for the hypothesis that extent of emotional processing would pre- dict amount of improvement. The single excep- tion to this overall negative result was a signifi- cant predictive relationship between what turned out to be the most useful therapy process variable--HR--and one of the more useful outcome measures--number of daily intrusive combat memories counted by the subject. Sub- jects who experienced a greater HR increase during the first flooding session showed a greater decrease in number of daily intrusive combat memories over the course of the flooding therapy. There were also trends for greater WSH and ASH of HR to predict the same decrease. Similar process-outcome correlations involving HR were reported in the study of emotional processing during exposure treat- ment of O C D . 4 Thus, the present results pro-

vide limited support for the hypothesis that successful emotional processing of pathologic fear requires the activation of the fear structure, as manifest in measurable psychophysiologic arousal during therapy.

Contrary to prediction, mobilization of self- reported anger or guilt during the flooding therapy was not found to predict a worse therapeutic outcome. These emotions appeared to have habituated about as well as self- reported fear during the flooding therapy. How- ever, in view of our previous clinical impressions to the contrary, 17 we believe this question war- rants further investigation, possibly incorporat- ing in-depth measures of these negative emo- tions 384° rather than the single crude self-report measures used in the present study.

ACKNOWLEDGMENT

Dr. Terence Keane and Dr. Judith Lyons provided a treatment manual for use in this work. Heike Croteau provided technical assistance.

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1. Boudewyns PA, Shipley RH. Flooding and Implosive Therapy. New York, NY: Plenum, 1983,

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3. Lang PJ. The cognitive psychophysiology of emotion: fear and anxiety. In: Tuma AH, Maser JA (eds): Anxiety and the Anxiety Disorders. Hillsdale, N J: Erlbaum, 1985:131- 170.

4. Kozak M J, Foa EB, Steketee G. Process and outcome of exposure treatment with obsessive-compulsives: psycho- physiological indicators of emotional processing. Behav Ther 1988;19:157-169.

5. Foa EB, Kozak MJ. Treatment of anxiety disorders: implications for psychopathology. In: Tuma AH, Maser J (eds): Anxiety and the Anxiety Disorders. Hillsdale, NJ: Erlbaum, 1985:421-452.

6. Black JL, Keane TM. Implosive therapy in the treat- ment of combat related fears in a World War II veteran. J Behav Ther Exp Psychiatry 1982;13:163-165.

7. Fairbank JA, Keane TM. Flooding for combat-related stress disorders: assessment of anxiety reduction across traumatic memories. Behav Ther 1982;13:499-510.

8. Keane TM, Kaloupek DG. Imaginal flooding in the treatment of a posttraumatic stress disorder. J Consult Clin Psychol 1982;50:138-140.

9. McCaffrey RJ, Fairbank JA. Behavioral assessment and treatment of accident-related posttraumatic stress dis- order: two case studies. Behav Ther 1985;16:406-416.

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6-yr-old boy's posttraumatic stress disorder. Behav Res Ther 1986;24:685-688.

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