Exposing Narrative Exposure Therapy

A coding manual has been created by the research team to assess the posited mechanism of change.

The primary outcome (process) measure is autobiographical memory integration (ABMI) as this is a posited mechanism of change in NET. An existing coding measure (Jager et al., 2014; Lane, 2019) has been adapted for the purpose of the study, to include more areas measuring phenomenological constructs of autobiographical memory. The coding measure that has been created by the researcher will cover areas such as: Total word count of narratives (Gray & Lombardo, 2001); disorganisation (Harvey & Bryant, 1999)- repetition of phrases, confusion, and disjointedness; fragmentation (Foa et al., 1995)- unfinished thoughts, repetition of words, speech filler; vividness; time and place details; emotional distancing and sensory details (Boyacioglu & Akfirat, 2014). The measure will be used to code transcripts on a session-by-session basis and is therefore a process measure (primary aim of study).

The IES-R (Weiss & Marmar, 1997) will be used every session to assess symptoms of post-traumatic stress disorder. It is a 22 item self-report questionnaire, and is divided into three subscales, with 8 items on intrusion and avoidance: 6 on hyperarousal. The measure assesses Intrusion, avoidance and hyperarousal in PTSD over the last seven days. Answers on the measure ranges from 0 = Not at all; 1 = A little bit; 2 = Moderately; 3 = Quite a bit; 4 = Extremely, there are no specific cut off scores; however, scores over 24 indicate concern, with higher scores related to higher levels of distress.

The DAAS-21 (Lovibond & Lovibond, 1995) will be used every session to assess depression, anxiety, and stress, it is a self-report questionnaire ranging over the last seven days. The DAAS-21 measures general psychological distress as an outcome measure (secondary aim of study). The measure consists of 21 items which are divided into 3 subscales with 7 questions for each subscale. Answers range on a scale from 0= Did not apply to me at all; 1= Applied to me to some degree, or some of the time; 2= Applied to me to a considerable degree or a good part of time; 3= Applied to me very much or most of the time. Scores of 10 and above on the depression sub scale indicates mild difficulties with depression; 8 and above on the anxiety sub-scale indicates mild difficulties with anxiety, and 15 and above on the stress sub-scale indicates mild difficulties with stress.

The Polar H10 chest strap will be used to collect heart rate data (heart rate- HR and heart rate variability- HRV). The Polar H10 has been shown to be a reliable and valid measure of HR and HRV; even when compared to an ECG as gold standard (Gilgen-Ammann et al., 2019; Speer et al., 2020). HRV measures physiological arousal and is the variation in time between heartbeats, by taking 5-minute segments of heart rate recordings, will allow for visual analysis of the root mean square of the successive differences between R-R intervals (rMSSD). HRV will be Measured every session pre- and post-narration and re-narration and used as a before and after measure to see how it changes over therapy.

The process of exposure and habituation are typically measured through Subjective Units of Distress Scale (SUDS; Foa & Kozack, 1986; Wolpe & Lazarus, 1966), which is a person's subjective account of distress on a set scale. Participants will be asked to rate their level of distress on a scale from 0 (no distress) to 10 (maximum distress), at the start, middle, and end of their trauma narrations. This is to see if how this relates to HR data.

The Body Perception Questionnaire Short Form (BPQ-SF; Porges, 1993; Kolacz et al., 2018) is a 46 item self-report measure that assesses a person's perception of body awareness and autonomic reactivity. The measure's items are based on the autonomic nervous system, and a set of neural pathways that connect the brain and body. It assesses a person's experiences of reactivity in their organs and tissues that are regulated by the autonomic nervous system. . The first domain and subscale is body awareness with high scores reflecting hypersensitivity, whereas low scores reflect low hyposensitivity. The second domain, Autonomic Reactivity has two subscales, Supradiaphragmatic Reactivity which measures the responses of autonomically-innervated organs above the diaphragm. The second subscale Subdiaphragmatic Reactivity measures the response of autonomically-innervated gastrointestinal organs below the diaphragm.

The feasibility and acceptability of the study will be investigated by conducting follow up change interviews with participants approximately one month after completing the treatment. In this instance, the participant will be asked to provide feedback on their experience of receiving treatment, including in terms of barriers and fascinators to engagement. The interviews will be conducted by an external researcher, i.e. another Trainee Clinical Psychologist. The interviews will be recorded and sent to the researcher and they will then be transcribed, after transcription content analysis will be applied to them.

The Life Events Checklist (LEC-5) which is part of the PCL-5 will be used in the proposed study. The LEC-5 is not an outcome measure but will be used to assess the number and type of traumatic events a person has experienced which is being collected as demographic information.