Understanding PTSD and the PDS^® Assessment

In addition, Foa cites other factors that can lead to PTSD, including:

• Previous psychiatric disorders



• An avoidant coping style



• Experiencing numbness or dissociation during or immediately after the trauma



• Fearing for your life during the trauma

Research has found populations at increased risk of developing PTSD include:^3,5,6

• Military troops



• First responders to disasters or medical emergencies including police, firefighters, rescue workers, emergency medical and mental health care providers



• Survivors of terrorist attacks, bombings, accidents, physical and sexual abuse, rape, political violence, repression and torture



• Survivors of natural disasters, such as earthquakes, floods, or hurricanes



• Witnesses of traumatic events



• Families and friends of victims

Research also has revealed other factors that contribute to the likelihood of developing PTSD, including:^1,5,6

• Gender—women are more likely to develop PTSD



• Individuals who were abused as children or who have had other previous traumatic experiences



• Those with prior vulnerability factors such as childhood trauma, lack of functional social support, and concurrent stressful life events



• Those with a social environment that produces shame, guilt, stigmatization or self-hatred

Severity and Duration of PTSD

According to Foa, three primary factors contribute to the severity and duration of PTSD: 1) the make up of the individual; 2) the nature of the trauma and how the individual interprets the traumatic event; and 3) post-trauma factors. She says, "People who prior to the trauma view the world and themselves either extremely negatively or extremely positively are more likely to experience a more severe and/or longer lasting PTSD than people who have more flexible perceptions.”

Additionally, studies reveal that deliberate, man-made violence (e.g., war, rape) result in longer lasting mental health effects than natural disasters or accidents.⁶

The PDS Assessment: Designed to Facilitate Diagnosis

Experts generally agree that the best way to diagnose PTSD is to combine findings from structured interviews and assessments.¹ Assessments like the PDS test are especially helpful to address a clinician’s concerns that some patients might be either denying or exaggerating their symptoms.

"We know that over half of the people in the U.S. population have had at least one trauma in their life and the numbers are higher in mental health clinics,” says Foa. "The PDS test was developed to be a screener that will help alert us to the possibility that the person has PTSD. We created it in such a way that it assesses all the criteria of the DSM-IV [guidelines] for PTSD."

The test is a self-report instrument with 49 items, requiring 10–15 minutes for the patient to complete. It was written for an 8th grade reading level and asks questions to help determine if all the DSM-IV criteria for a PTSD diagnosis are met.

Meets all DSM-IV Diagnostic Criteria

The PDS test is one of the only self-report assessments that meets all the criteria of the DSM-IV. It asks if the patient has experienced trauma, what type of trauma, how long ago the trauma happened, and how long it lasted. It also inquires about problems in daily functioning and the presence and severity of each of the 17 PTSD symptoms of the DSM-IV.

Paul Arbisi, PhD, Staff Clinical Psychologist at the Minneapolis Veterans Administration Medical Center and in private practice, uses the PDS test in his work as a vital tool in determining eligibility for compensation as a result of disability stemming from PTSD. He has the PDS test administered as a screener for the use of a structured diagnostic interview within the context of a multi-method comprehensive evaluation.

"The advantage of the PDS test," states Arbisi, "is that it evaluates all DSM-IV symptoms of PTSD as well as the severity of each symptom. Further, the PDS test evaluates the degree of impairment associated with PTSD and the impact the PTSD symptoms have on activities of daily living. Finally, in completing the PDS test, the individual is asked to record all traumatic events experienced during their life."

According to Arbisi, in disability evaluations in the context of civil litigation, workers compensation or award of veterans’ benefits, PTSD is often claimed based on a single incident. "The ability of the PDS test to document and evaluate multiple traumatic events across the individual’s lifetime serves as a distinct advantage for the clinician in reaching a clinical decision regarding causality and aids in apportioning percentage of disability resulting from PTSD to specific events,” he says.

Easy to Use
Pamela M. Peterson, PhD, is a clinical psychologist in private practice in rural Southeastern Minnesota. Peterson has found that the manner in which the PDS test tracks the symptom categories necessary to make a DSM-IV diagnosis makes outcomes testing and diagnostic formulation for PTSD a quick and easy task to complete. Most of Peterson’s evaluations are completed on farms and in homes, thus the practical aspects of the instrument are a significant asset and are appreciated by psychologists working in rural environments.