Developing a Symptom Validity Test for posttraumatic stress disorder: application of the binomial distribution

The past decade has witnessed a significant increase in research on the detection of malingered Posttraumatic Stress Disorder (PTSD) in civil litigation, other disability pension contexts, and in forensic cases. This article reviews the basic principles and statistical procedures that can be used to design and develop a Symptom Validity Test (SVT) for PTSD. We demonstrate how the practical application of the binomial distribution can detect response bias in specific psychiatric disorders such as PTSD and can provide empirically grounded probabilistic evidence of malingering. We cite the Morel Emotional Numbing Test for Posttraumatic Stress Disorder (MENT) as an example.