Many of the clinical scales, as well as the aggression scale, also have a number of subscales to provide more nuanced information bout each of the clinical conditions. For example, the Borderline Features scale has four subscales: Affective Instability, Identity Problems, Negative Relationships and Self-Harm. The resulting score profiles can be compared to either normative or clinical populations. Raw scores are converted to T-scores using tables provided in the scoring manual. These tables were generated using either normative or clinical samples that were census matched and standardized (Morey, 2007). The manual provides average scores for each of the subscales, for example, the average T score for Borderline Traits is 59, indicating that individuals falling below this number are emotionally stable and do not reflect borderline traits. The individual mean scores for each scale vary and are presented within the testing manual (Morey, 2007).

Test Application

The PAI has been used in a number of different settings, including inpatient and outpatient psychiatric treatment, personnel selection, medical screening, criminal justice and forensic settings, assessment of PTSD in veterans, and substance abuse treatment and assessment. The scale is very relevant to clinical diagnosis, making it widely used in any setting where clinical diagnoses are suspected or sought. For example, the scale can be useful in diagnosing clinical depression, schizophrenia, anxiety and severe personality disorders, such as borderline personality disorder and anti-social personality disorder (Morey, 2007).

Because the assessment can be self administered to an individual or group, and because it is relatively quick to complete (less than an hour) and is provided at a low reading level (grade 4), the test is popular in both clinical treatment settings and research settings (Blais, Baity, & Hopwood, 2010).

Strengths & Weaknesses

The PAI is popular due to a number of its strengths. The test was developed using a sound theory of construct development...

In addition, the inventory provides information useful for treatment planning with the five relevant treatment scales, which can help clinicians in not only identifying the issues that require attention but also in selecting the forms of treatment most likely to be successful for any given client. The PAI is also relatively easy to use and to interpret and does not require sophisticated scoring procedures (Morey, 2007). The test has been found to be psychometrically sound, with validity and reliability being in acceptable ranges consistently. Finally, the PAI has been validated and standardized on large community and clinical samples that have been matched with census data to ensure the greatest levels of generalizability (Morey, 2007).
Despite the many strengths of the PAI, the inventory does also have some weaknesses. Specifically, all self-report scales are subject to manipulation, although the four validity scales of the PAI do help considerably in detecting any form of manipulation (Morey, 2007). The scale is somewhat limited in its coverage, as it does not cover all clinical conditions within the DSM-IV, and excludes symptoms related to eating, sexual functioning and dissociative behaviors and experiences. Finally, the PAI has been found to be less reliable among diverse samples, with internal consistency dropping to as low as .75 (Blais, Baity & Hopwood, 2010).