Use of the Pain Presentation Inventory in comparing personality traits with symptom presentation

Abstract

Evaluation of pain patients has revealed that a subset of patients report pain intensity and severity, functional disability, and physical limitations that do not reflect the degree of physiological damage at the pain site. Psychological factors, including personality traits, availability and type of coping strategies used, locus of control, sense of self-efficacy, and psychosocial factors such as social support and the presence of reinforcement, have been implicated in the experience, expression, maintenance, and duration of pain syndromes. Factors such as these are considered to be non-organic, as they are not direct physiological aspects of pain. Individuals suffering from chronic pain have been classified into distinct constellations in an attempt to better understand the psychological mechanisms underlying the manifestations of their pain symptoms in the absence of corresponding tissue damage. The MMPI-2 is a frequently-utilized instrument in the evaluation of pain patients, and has yielded a prominent typology that categorizes pain patients into one of four "types" based upon MMPI-2 scale elevations and configurations. The Pain Presentation Inventory (PPI) is a previously-unexplored measure that combines patient self-report data with clinician evaluation of overt patient behaviors during interview to generate a patient "type" that categorizes each patient based on a combination of process, either unconscious or conscious, and motivation, either internal or external. These patient types, founded on DSM-IV diagnostic entities, are identified as Pain Disorder Associated with Psychological Factors (Somatoform), Psychological Factors Affecting Physical Condition (Compensation), Factitious Disorder with Predominantly Physical Signs and Symptoms (Factitious), or Malingering. Group type for patients who are unable to be classified as one of these four types is deferred. An investigation of patients in each PPI group revealed similar MMPI-2 profile configurations for the four PPI patient types, as well as for the patients whose group membership was deferred. With respect to individual scale elevations. Compensation and Factitious patients exhibited the highest levels of psychopathology, whereas Malingering patients yielded a profile indicative of greater psychological health. Malingerers did not, as hypothesized, score significantly higher than the Somatoform. Compensation, and Factitious patients on the Non-Organic Signs scale. Convergent validity between group profiles and DSM-IV diagnostic classifications was supported to some extent. Treatment implications based upon the unique characteristics of each PPI group, their presentation of pain symptoms, sense of self-efficacy and locus of control, and corresponding use of specific coping strategies, are discussed. As this is the first exploratory study to ever use the PPI, further research is warranted in order to evaluate the PPI's ability to usefully classify pain patients.