Using the Personality Assessment Inventory to Diagnose and Discriminate between Major Depressive Disorder and Generalized Anxiety Disorder in a University Counseling Center

This study investigated the utility of the Personality Assessment Inventory (PAI) for diagnosing and discriminating between Major Depressive Disorder (MDD) and Generalized Anxiety Disorder (GAD) with university counseling center clients. Participants were 1541 male and female students who received services at a student counseling center at a large university. Participants were classified as MDD, GAD, or Other Diagnosis (OD) based on the diagnosis determined by the treating clinician, and PAI profiles were compared between the three groups.

The PAI Structural Summary-Revised contains Diagnostic Consider Clusters (DCC) that were designed to identify PAI scales/subscales that are typically elevated or suppressed when a particular disorder is present. The DCC’s for MDD and GAD were examined and the results demonstrated that the criteria for the DCC for MDD were met by 2.2% of the MDD group, and the criteria for the DCC for GAD were met by 3.8% of the GAD group. A discussion of these findings is offered, and the appropriateness of using the DCC’s for the purpose of diagnosis with any population is questioned. Additionally, DCC’s for MDD and GAD for use with university counseling center clients are proposed.

Finally, discriminant analysis (DA) was employed to develop various discriminant functions that can be used to classify individual PAI profile data into specific diagnostic groups. In particular, one discriminant function was created that is capable of examining any PAI profile, and classifying it as either MDD or OD. A second discriminant function was produced that can analyze any PAI profile and categorize it as either GAD or OD. The final discriminant function was developed to evaluate a PAI profile that represents either MDD or GAD and determine which diagnosis is appropriate. Each discriminant function was shown to accurately predict the associated diagnoses. A discussion of the various predictor variables is offered. Taken together, these results support the use of the PAI for diagnosing and discriminating between MDD and GAD with university counseling center clients.