The population being studied is female sexual assault survivors. Participants are females aged 18 years and older who have experienced at least one incident of sexual assault. Convenience sampling is used to recruit volunteers to participate in the study from local counseling agencies. Convenience sampling offers an approach to obtaining a sample using whoever is available to participate in the study (Jackson, 2016). For the purpose of this study it would be beneficial for participants to volunteer to participate to show a willingness to participate and fully engage in the treatment processes.
Participants of the study will meet the following criteria to be included: female, aged 18 years or older, experienced at least one incident of sexual assault, actively experiencing symptoms of posttraumatic stress disorder (PTSD) related to sexual assault. Exclusion criteria includes males, individuals under the age of 18, no experience of sexual assault, no active symptoms of PTSD, PTSD symptoms not related to sexual assault, participating in other forms of treatment, and taking of medication for the purpose of treating of symptoms related to PTSD.
Screening of participants will take place by allowing individuals to refer themselves to participate in the study or agree to participate after being referred by a treatment provider at a local counseling agency and by gathering background information. Demographic information such as age, race, and socioeconomic status is included in the background information along with number of sexual assault incidents experienced, age when the incident happened, previous treatment received, and evaluation of current symptoms of PTSD. Background information is collected through a self-report questionnaire. Evaluation of current symptoms of PTSD occurs using the Posttraumatic Stress Disorder Checklist.
Participants are briefed on the research process using informed consent. Informed consent includes, but is not limited to, an explanation of the purpose of the study and the procedures involved, risks and benefits of participating in the study, the limits of confidentiality, and how the research findings will be used (Knight & Tetrault, 2017).
The Posttraumatic Stress Disorder Checklist – 5 is used to measure symptoms of PTSD in participants after implementation of treatment. The PCL-5 is a self-report measure with 20 items that match to PTSD symptom criteria in the Diagnostic and Statistical Manual of Mental Disorders (Blevins, Weathers, Davis, Witte, & Domino, 2015). The PCL-5 uses a 5-point scale ranging from 0 = not at all to 4 = extremely to indicate how bothersome each PTSD symptoms has been over the past month. The item scores are added together to produce a continuous measure of PTSD symptom severity. The PCL-5 is a revision of the PCL to reflect current PTSD criteria in the DSM-5. Cut scores to determine a diagnosis of PTSD have yet to be determined; however, a provisional diagnosis of PTSD may be gained by considering items rated as 2, or moderately, and higher as symptoms then applying the DSM-5 diagnostic criteria rules (Blevins, Weathers, Davis, Witte, & Domino 2015).
The Posttraumatic Stress Checklist – 5 (PCL-5) has shown to be a reliable and valid assessment in measuring PTSD symptom severity. The PCL-5 has high internal consistency (α = .94) and showed to be comparable to similar measures evaluating PTSD. The items within the PCL-5 showed good consistency with a median test-retest reliability coefficient of .68. Discriminant validity correlations were established between the PCL-5 and other assessments of PTSD and were found to be moderately correlated with related constructs such as depression (r = .60) and least correlated with constructs that are unrelated such as Antisocial Personality Features (r = .39) and Mania (r = .31) (Blevins, Weathers, Davis, Witte, & Domino, 2015).
Peer reviewed literature supports the PCL-5 being a psychometrically sound measure of PTSD symptoms as indicated in the DSM-5. It is said to be closely comparable to the original version of the PCL. It can be used for a variety of needs such as research and clinical assessments, quantifying symptom severity, making a provisional diagnosis, and evaluating the prevalence of PTSD (Blevins, Weathers, Davis, Witte, & Domino, 2015). While the Clinical Administered PTSD Scale for DSM-5 is the preferred assessment when diagnosing and measuring PTSD, it takes a significant amount of time to administer and requires the professional to be trained. The PCL-5 allows clinicians and other professional to have a tool that relies on self-reported information to help determine if individuals would benefit from treatment (Geier, Hunt, Nelson, Brasel, deRoon-Cassini, 2018).
The decision to use the PCL-5 is based on several factors. The PCL-5 is the revised version of the original PCL to coincide with the updated PTSD diagnostic criteria in the DSM-5. It would be ideal to use an assessment that corresponds to the most current diagnostic criteria. It is one of a few measures for PTSD that has shown excellent psychometric properties and is aligned with the DSM-5 (Geier, Hunt, Nelson, Brasel, deRoon-Cassini, 2018). Additionally, the PCL has shown to have good psychometric properties when used in populations where individuals who have experienced trauma are seeking help (Bliese, Wrights, Adler, Cabrera, Castro, & Hoge, 2008). The structure of the PCL-5 was also taken into consideration as it is a self-report measure which is easy to administer and score. Ultimately the PCL-5 is a widely used tool when measuring PTSD symptoms and it appears to be a reliable and valid measure in assessing the presence of PTSD symptoms and their severity (Schwarz, Baber, Barter, & Dorfman, 2018).
Items on the PCL-5 list problems that individuals sometimes face in response to stressful situations. Individuals are asked to rate how much they were bothered by certain problems that individuals may experience as a result of a stressful situation. Examples include “repeated, disturbing, and unwanted memories of the stressful situation; avoiding memories, thoughts, feelings related to the stressful experiences; having strong negative feelings such as fear, horror, anger, guilt, or shame; feeling jumpy or easily startled; and trouble falling asleep or staying asleep” (Weathers, Litz, Keane, Palmieri, Marx, & Schnurr, 2013). The PCL-5 yields interval data as it uses a 5-point Likert type scale from 0 being not at all and 4 being extremely to obtain a total score ranging from 0 to 80.
The variable under investigation is the severity of PSTD symptoms after receiving either cognitive processing therapy or eye movement desensitization and reprocessing therapy. Items on the PCL-5 reflect diagnostic criteria for PTSD as outlined in the DSM-5 and it is widely used to assess the presences and severity of PTSD symptoms therefore it is an appropriate measure to use for the purpose of this research.
The proposed study is a pre-experimental group comparison research study using posttest measures of PTSD symptoms as assessed using the Posttraumatic Stress Disorder Checklist for the DSM-5 (PCL-5) after engaging in Cognitive Processing Therapy (CPT) or Eye movement Desensitization and Reprocessing therapy. Schwarz, Baber, Barter, & Dorfman (2018) used pre and post treatment assessment of PTSD symptoms using multiple measures including the PCL-5 to investigate the efficacy of EMDR therapy. Holiday, Holder, Williamson & Suris (2016) evaluated the efficacy of CPT in treating PTSD and used the PCL to assess symptoms severity. The proposed study will compare the difference in symptoms of PTSD among female sexual assault survivors between those who receive CPT and EMDR as assessed by the PCL-5.
Treatments used within this study are CPT and EMDR. Participants will be randomly assigned to one of two groups. One group will engage in CPT and the other group will engage in EMDR therapy. Cognitive processing therapy is an evidence-based form of therapy that focuses on identifying and challenging cognitions related to trauma (Holiday, Holder, Williamson, & Suris, 2016). Cognitive processing therapy will occur over a 6-week period with bi-weekly, 1-hour individual sessions. A trauma narrative approach will be used to focus on the specific traumatic experience of sexual assault and challenge cognitions related to the specific incident.
EMDR therapy uses a trauma perspective to approach treatment and it presumes that unprocessed memories are the basis for psychopathology as the interruption of the processing of information causes the storing of distressing memories (Acarturk, Konuk, Cetinkaya, Senay, Sijbrandij, Gulen, & Cuijpers, 2016).
During the course of EMDR treatment clients are asked to focus on one specific traumatic event. The individual recalls the memories linked to that event and the negative beliefs created surrounding the trauma. While doing so, individuals are stimulated to make rapid eye movements or other bilateral dual attention stimulations. The counselor then guides the client to develop positive cognitions (Schwarz, Baber, Barter, & Dorfman, 2018). EMDR therapy will occur over a 6-week period with bi-weekly, 1-hour individual sessions. Participants will be asked to focus on the specific incident of trauma and negative cognitions that are causing distressing symptoms while being stimulated to make rapid bilateral eye movements for the purpose of creating positive cognitions.
Sexual assault refers to a multiple of incidents such as indecent exposure to rape. The World Health Organization describes sexual assault as being “any sexual act, attempt to obtain a sexual act, unwanted sexual comments or advances, or acts to traffic, or otherwise directed, against a person’s sexuality using coercion, by any person regardless of their relationship to the victim, in any setting, including but not limited to home and work” (Long & Butler, 2018, p. 87). For the purpose of this study the above definition of sexual assault will be used.
The items on the PCL-5 correspond with diagnostic criteria listed in the DSM-5. For the purpose of this study PTSD symptoms will be defined using the DSM-5. Items 1-5 reflect cluster B criteria regarding intrusive symptoms; items 6-7 reflect cluster C criteria regarding avoidance of stimuli associated with the traumatic event; items 8-14 reflect cluster D criteria regarding negative alternations in mood and cognitions; and items 15-20 reflect cluster E items regarding alterations in arousal and reactivity. A total score indicating symptom severity will be obtained by summing the scores for each item (Weathers, Litz, Keane, Palmieri, Marx, & Schnurr, 2013).
Participants will be assessed posttreatment to measure symptom severity. Upon completion of treatment sessions, participants will be asked to complete the PCL-5 to measure symptom severity after participating in CPT or EMDR. Controls for the study include using the same assessment for each participant regardless of the treatment they receive. Assessment of symptoms for each participant occurs at the same time, one-week post treatment. Each participant will engage in bi-weekly sessions for 1 hour for 6 weeks total with the same therapist through the course of the study.
Therapists for the study will be licensed professional counselors, have specific training in CPT or EMDR, and will be assigned to administer treatment for that group only. Creating consistency with the assessment used, when data is collected, and length of treatment and duration of sessions is intended to limit any discrepancies between assessment results and time passed between assessment. Training and consistency in therapists administering treatment for participants is intended to limit discrepancies between how therapists engage with participants, how they administer treatment that may influence treatment outcomes, and to ensure they have the necessary training and education to administer treatment appropriately.
The PCL-5 yields interval data therefore interval data will be collected post treatment. Participants will receive a total score for symptom severity once treatment has concluded. An independent-groups t-test will be used to determine the statistical significance, if any, of PTSD symptoms among female sexual assault survivors between those who receives CPT and EMDR therapy. The independent-groups t-test compares the means of two samples with different participants (Jackson, 2016). The decision to use the independent-groups t-test is based on the type of data being collected and the investigation of a difference between two groups independent of each other. The proposed study is collecting interval data from the PCL-5 and comparing the difference of PTSD symptoms among female sexual assault survivors between those who receive CPT and EMDR.
The results of the independent groups t-test analysis will be used to test for a statistically significant difference in PTSD symptoms among female sexual assault survivors between those who receive CPT or EMDR treatment using a significance level of .05 for a one-tailed hypothesis. The alternate hypothesis predicts that CPT will be more effective in reducing PSTD symptoms among female sexual assault survivors. The null hypothesis suggests there will be no difference in symptoms among female sexual assault survivors between those who receive CPT and EMDR therapy. If the independent groups t-test analysis indicates a statistically significant difference in PTSD symptoms post treatment, the null hypothesis shall be rejected in favor of the alternate hypothesis. This will imply that CPT is more effective in treating symptoms of PTSD among female sexual assault survivors.
