Participants
Participants were originally 12 patients with underweight and PTSD, who underwent inpatient treatment for their eating disorder, between February 2017 and July 2019. Mean age was 25.73 (SD 11.09, range 16–58). As two patients dropped out of the study early, in the end 10 participants were included. One participant discontinued clinical treatment during the baseline period of the study, because of the difficulty with participating in a group; she was diagnosed with an autism spectrum disorder. In a dropout interview, she indicated that the upcoming trauma-treatment was a reason for her to try and remain in clinical treatment than a reason to stop clinical treatment. The other participant discontinued after three IMRS treatment sessions. In a dropout interview, she indicated that her trauma complaints diminished immediately through the IMRS sessions. However, the sessions consumed so much energy that she felt she had too little energy left to make the most of her clinical eating disorder treatment. She preferred a sequential treatment rather than a parallel treatment. Because this study was a first concept of proof, we reported on the 10 participants that completed the IMRS treatment. All participants were female and of Dutch nationality. Inclusion criteria were: (1) a BMI between 14 and 16.5; (2) current DSM 5 diagnosis for AN or Other Specified Feeding and Eating Disorder (OSFED); (3) a PTSD diagnosis as defined by DSM-5 and determined with the Structured Clinical Interview DSM (SCID-5) PTSD section (First et al., 2016), and the Clinically Administered PTSD Scale (CAPS-5) interview (Weathers et al., 2018); (4) age between 16 and 65 years; (5) an indication for inpatient treatment; (6) willingness to participate in the study (signed informed consent). Exclusion criteria were: (1) estimated IQ < 80; (2) acute suicide risk; (3) substance dependence; (4) life threatening physical condition; (5) start of new medication within 3 months prior to the start of the study; (6) ongoing trauma; (7) a medical history of psychosis, bipolar disorder, or borderline personality disorder.
Of the 72 patients that were clinically admitted in the defined period of time, 12 met all inclusion criteria. All participants that met the inclusion criteria agreed to participate in the study and provided written consent.
Table 1 presents the demographic and clinical data of the completers group (N = 10).
Table 1
Demographic and clinical data of the completers group (N = 10).
Variable
|
Age (Mean, SD)
|
Range 16–58 (n = 10)+
|
26.4 (12)
|
Gender (Number, %)
|
Female
|
10 (100%)
|
Completed educational level (Number, %)
|
Pre-vocational secondary education
|
3 (30%)
|
Secondary vocational education
|
3 (30%)
|
Senior general secondary education
|
1 (10%)
|
Pre-university education
|
2 (20%)
|
University education
|
1 (10%)
|
Feeding and eating disorder (Number, %)
|
Anorexia Nervosa
|
9 (90%)
|
Other specified feeding and eating disorder
|
1 (10%)
|
Body Mass Index, start of the study (Mean, SD)
|
Range 14.9–17.8
|
15.6 (1.2)
|
Body Mass Index, start IMRS phase (Mean, SD)
|
Range 14.6–18.4
|
16.7 (1)
|
Number of participants per trauma category (LEC-5 categories++)
|
Physical assault (for example, being attacked, hit, slapped, kicked, beaten up)
|
4
|
Sexual assault (rape, attempted rape, made to perform any type of sexual act through force or threat of harm)
|
5
|
Other unwanted or uncomfortable sexual experience
|
2
|
Combat or exposure to a war-zone (in the military or as a civilian)
|
1
|
Any other very stressful event or experience
|
1
|
Total CAPS-5+++ score (Mean, SD)
|
Range Caps total 33–58
|
44.8 (9.1)
|
+ One outlier of age 58. Without outlier Range 16-30, Mean 22.9, SD 4.9
++ Weathers, Blake, Schnurr, Kaloupek, Marx, & Keane, (2013).
+++Clinical-Administered PTSD scale for DSM-5.
Procedure
All patients who register with the expertise center for FED, were seen by a psychologist, a medical doctor, and the family present was seen by a family therapist. Next, the SCID-I for DSM-IV-TR was administered to determine the diagnosis of PTSD (Glasofer & Riegel, 2015). Hereafter all the information was discussed in a multidisciplinary meeting where the treatment advice was compiled. During this multidisciplinary meeting, a checklist was used with the inclusion criteria for the IMRS study. Patients who met the inclusion criteria received a brief oral explanation and an information letter (including an informed consent form) about the IMRS study in the admission interview. In the information letter the IMRS method was explained, and because the treatment could temporarily cause emotional distress in patients (as do all therapies which focus on working through trauma), patients were fully informed on these effects. After several days, the patient was approached (by the first author) by telephone, asking whether they would like to participate in the study. After consent was obtained they were invited for CAPS 5, version last month (Boeschoten et al., 2015). The CAPS-5 was used because the Dutch version of the SCID-5 was not yet available at that time. With the CAPS-5 the DSM 5 diagnosis was reconfirmed. After the CAPS 5 the visual analogue scales (VAS) were personalized.
Design
This study was designed as an intervention study during an inpatient treatment program for FED with weekly assessments throughout baseline, therapy, and three weeks post-treatment, as well as a follow-up assessment after three months (Fig. 2). We used a randomized multiple baseline design with five baseline length conditions (6 to 10 weeks). The variation in baseline length gives the opportunity to distinguish between time effects and effects of the IMRS treatment. A randomization schedule for baseline lengths (2 participants per length: 6, 7, 8, 9 and 10 weeks) was determined a priori, and participants were allocated to these randomly predetermined baseline lengths based on inclusion order.
The participants were not informed about the duration of the baseline and were notified three days before the start of the IMRS. Due to a miscommunication 1 participant was given the wrong baseline length. This means there was one participant with 9 weeks baseline and three participants with 6 weeks baseline. One participant did not report any traumatic complaints during the screening, yet reported more and more PTSD complaints during the first weeks of clinical treatment[1]. This patient was therefore included in the study during her clinical treatment.
Power analysis
Although sophisticated statistical techniques to analyze data from case series over subjects have been developed, there is no simple power analysis method developed yet. We planned 10 participants. To give an impression of the power, this sample size yields 80% power to detect a large effect (Cohen’s d > 1) with a paired t-test at a two-tailed significance level of 0.05. Such an effect size is reasonable to expect given the pooled pre-post effect size of g = 1.48; 95% CI = [1.14; 1.82] for IMRS for PTSD (Morina et al., 2017).
Treatments and therapists
The inpatient treatment program for FED was five days a week with overnight stay. Patients went home during weekends. The program used cognitive behavioral change methods and focused on increasing weight and on factors that sustain the eating disorder for the particular patient. Three main meals and three in-between meals per day were supervised. Beside the meals, the program consisted of the following therapy components: 1) One hour ‘cognitive behavioral therapy’ (emphasis on maintaining factors of the eating disorder in the present and future, 2) two hours ‘eating behavior’ (aimed at normalizing the eating pattern), 3) two hours ‘body and movement-oriented therapy’ (focused on the overvaluation of the body, movement behavior and emotion regulation (De Lange et al., 2019), 4) one hour psycho education, 5) one hour ‘progress and goal meeting’, 6) 75 minutes ‘psychotherapy’, and 7) two hours ‘activity guidance’ (focused on expanding other areas of life; work, study, friendships, hobbies, sports; with the option to spend one hour on creative work).A parent and partner group was offered five times during clinical admission (psychoeducation about eating disorders, opportunity for support, recognition, understanding and advice).
The investigational treatment was IMRS. IMRS is a psychological treatment for processing traumatic experiences (Arntz, 2015; Arntz & Weertman 1999; Raabe et al., 2015; Smucker & Niederee, 1995). IMRS was given in addition to the regular inpatient treatment program for FED. The IMRS treatment consisted of 12 IMRS sessions of 90 minutes each, which were offered in 6 consecutive weeks. IMRS aims to change the meaning of traumatic experiences by experiencing imagined interventions that correct the dysfunctional emotional and interpersonal meanings attached to the trauma. In IMRS, the patient imagines the start of the traumatic event (to activate the trauma memory). When there is enough emotional activation (usually at the hotspot), the rescripting starts. The therapist, and later the patient (from their current perspective), then rescripts the traumatic experience to provide a more desirable outcome, while the patient is imagining this new script as lively as possible. This leads to change of maladaptive beliefs, more control over images, and improved possibilities to reassure oneself (Long & Quewillon, 2009). This way, the patient does not have to relive the full trauma in all its details. It is important, in this respect, that the rescripted outcome contains new and unexpected information for the patient, so that a lasting change of memory is created (Finnie & Nader, 2012).
The first IMRS session was a preparatory session, in which the therapeutic alliance was formed, the rationale and treatment were explained, and a list of experienced traumas was established. The therapist and patient discussed the order in which they would address the traumas. Also, current living circumstances were checked (to check whether there was enough distance from the perpetrator and enough safety to conduct trauma processing). The session ended with a pilot IMRS (using a mildly negative childhood memory) to familiarize the patient with the IMRS technique, and with a session evaluation. Patients were instructed to read the IMRS explanation hand-outs and reread the list of trauma-themes and change items and/or order if applicable before the following IMRS session.
Within each following session, the following sequential steps were followed:
1. Check for intrusions, nightmares, and emotions following the previous session. Discuss how this session affected the patient;
2. Agree upon which trauma theme to start with;
3. Have patient close eyes and retrieve traumatic memory;
4. Therapist (session 1–6) or Adult patient (session 7–12) steps into the image;
5. Therapist or adult patient intervenes and patients imagines this intervention;
6. Check whether the imagined situation is effectively under control and the child’s needs are met;
7. If the way of intervening was not successful: rewind and start again;
8. Stop when patient, from the point of view of the child, says ‘it is okay’;
9. Evaluate the rescripting (rescript another memory if time allows);
10. Evaluate the session;
11. Assign homework: review trauma list (for order and need or wishes to address traumas).
For a more detailed treatment description see Raabe et al. (2015). The IMRS sessions were given by postdoctoral trained registered psychologists (two health psychologists, two psychotherapists and one clinical psychologist). Therapists were trained during a one day workshop by Arnoud Arntz.
The therapists attended weekly group supervision (60 minutes). The supervision was led by the first author with the option of consulting the fourth author by telephone or email.
Treatment integrity
To assure that IMRS was carried out as designed, the treatment integrity was assessed. Treatment sessions were audio-recorded and the adherence was rated by two trained and independent master-level doctoral psychology students, with the use of the Imagery Rescripting Therapist Adherence and Competence Scale (Raabe, 2015). The raters were trained by the first author. Besides that, 4 IMRS sessions were rated by both raters to assess interrater reliability (Perepletchikova et al., 2007). The mean of the treatment adherence of all elements of IMRS was 0.80 (SD 0.071) (0 = the therapist didn’t demonstrated the particular intervention, 1 = the therapist demonstrated the particular intervention). This means that 80% of the prescribed elements was detected. Interrater reliability was good (intraclass correlation coefficient [ICC] = .66, p < .001 [adherence].
Instruments
The main primary outcome measure was the PTSD Scale-Self Report for DSM-5 (PSS-SR), which was used to assess the level of PTSD-related symptoms according to DSM-IV (Foa et al., 1993). The scale assesses the frequency of the trauma related symptoms during the last week (range 0–51), with a 4 point scale (3 = very often, always, 2 = often, 1 = sometimes, 0 = never). The completed scores are summed, a higher score is reflecting more PTSD symptoms. Sin, Abdin and Lee (2012) showed that the optimal cut-off point for the PSS-SR is 14 and the scale has high internal consistency and validity. Cronbach’s alpha in the present study was .87.
The second group of primary outcomes were core emotional problems and beliefs assessed with Visual Analogue Scales (VAS). The respondents indicated on a 100 mm line with two anchors, to what extent they agreed with an item (don’t agree at all – agree completely). The following ‘negative emotions’ items were presented 1) to what extent did you experience rage in the past three days, 2) to what extent did you experience guilt in the past three days, 3) to what extent did you experience shame in the past three days, 4) to what extent did you experience disgust in the past three days. In addition, three to four personalized ‘dysfunctional self-beliefs’ and ‘dysfunctional body-beliefs’ VAS scales with negative thoughts about the self and the body were added, which asked: to what extent did you suffer from your personalized negative thoughts about the self/body in the past three days? (not at all – extremely). An example of such an idiosyncratic VAS is ‘I’m fat’. The VAS scales were collected twice per week during baseline period, after each IMRS session, twice per week during the follow-up and once during the follow-up measure. We derived three composite scores from the VASs; a negative emotion score (the average of the emotion VASs), a dysfunctional self-belief score (the average of the idiosyncratic beliefs about the self) and a dysfunctional body-belief score (the average of the idiosyncratic beliefs about the body).
A second relevant question is whether PTSD-related cognitions, eating disorder problems, and emotion regulation difficulties also decline. Therefore the secondary outcome measures consisted of the Post-Traumatic Cognitions Inventory (PTCI), the Body Mass Index (BMI), the Eating Disorder Evaluation-Questionnaire (EDE-Q) and the Difficulties in Emotion Regulation Scale (DERS).The secondary study parameters were administered at fixed timepoints (weekly during baseline period, at the start, mid and end of the IMRS, weekly during follow-up and once during follow-up measure).
The Post-Traumatic Cognitions Inventory (PTCI) was used to measure trauma-related cognitions. An example of a question is ‘I am a weak person’ or ‘The world is a dangerous place’. It assesses the frequency of the trauma-related cognitions during the last week (range 0–51), with a 4 point scale (0 = never, 1 = sometimes, 2 = often, 3 = very often, always). The scores are added together, the higher the score the more trauma-related cognitions. Van Emmerik et al. (2006) and Foa et al. (1999) found a high internal consistency and high two-week test-retest reliability of the PTCI. Cronbach’s alpha of the total score in the present study was .91.
BMI is a relative weight measure and is calculated as follows: body weight in kg / body height in m2. During inpatient treatment, height is measured once during initial screening, and weight is measured at least two times a week. We asked patients for permission to use the height and weekly weight information from their medical files.
The Eating Disorder Evaluation-Questionnaire (EDE-Q 6.0) is a 28-item self-report questionnaire which is used to measures core attitudinal features of eating disorders for the past 28 days, and the frequency of core eating disorder behavior from the previous 7 days (Fairburn & Beglin, 2008). The EDE-Q includes features of eating disorders and specific behavioral symptoms. An example of a feature is ‘eating concern’ and of a specific behavioral symptom ‘self-induced vomiting’. The EDE-Q demonstrated reliability of scores, but additional research is needed to generalize these findings (Berg et al., 2012). Cronbach’s alpha of the total score in the present study was .89.
The Difficulties in Emotion Regulation Scale (DERS) is 36 item self-report questionnaire which is used to measure difficulties with emotion regulation (Gratz & Roemer, 2004; Neumann et al., 2010). An example of a question is ‘I know what my feelings are’ or ‘When I’m upset, I feel ashamed about it’. The DERS has good test–retest reliability (Gratz & Roemer, 2004) and high internal consistency within clinical patients (Fox et al., 2007). Cronbach’s alpha in the present study was .92.
Statistical analysis
Mixed regression was used for the primary (PSS-SR, VAS) and secondary (PTCI, BMI, EDE-Q, DERS) quantitative outcome parameters, to assess differences between treatment, post-treatment and follow-up measures compared to baseline in average scores and linear change. Fixed variables were a dummy to indicate treatment, a dummy indicating the post-treatment and a dummy indicating the follow-up measure (so that baseline is the reference), and time by phase interactions represented by a centered linear time effect within each phase (Vlaeyen et al., 2001). Random variables were a random intercept to capture between subject outcome variation, plus Autoregressive Moving Average Model (ARMA1.1) for the within-subject covariance structure of the repeated part. ARMA1.1 had the best fit for all the questionnaires, except for the VAS scales, in which case we used Autoregressive model (AR1). Given their skewed distributions, the transformed (101 - raw score in mm) outcome measures ‘VAS body’ and ‘VAS belief’ were analyzed by Generalized Linear Mixed Models with a gamma distribution and log-link, which is suitable for (very) skewed distributions. We assessed the full model with all predictors.
Cohen’s d was calculated as effect size of the change of (post-)treatment resp. follow-up compared to baseline based on estimated means from the mixed regression as numerator and baseline SD as denominator (Arntz et al., 2013; Vlaeyen et al., 2001).
[1] As Zimmerman & Mattia (1999) indicate, some patient feel uncomfortable to share their trauma complaints at the start of treatment. They advise to keep on evaluating on trauma complaints during treatment.