Abstract
This study was designed to assess the ability of the Minnesota Multiphasic Personality Inventory (MMPI‐2) MacAndrew Alcoholism Scale (MAC‐R) to differentiate between outpatients with personality disorders with Substance‐Related Disorders (SRDs) and without SRDs. MMPI‐2 validity, clinical, and MAC‐R scale scores were compared in an SRD Cluster B group (comprised of Narcissistic, Antisocial, Borderline, and Histrionic; n = 15), a non‐SRD Cluster B group (n = 33), and a non‐SRD group with personality disorders from Clusters A and C (n = 18). Results revealed that the substance‐abusing Cluster B group scored significantly higher on the MAC‐R ( p < .0001) as well as the Psychopathic Deviate scale ( p < .01). Dimensional analyses illustrated that MAC‐R scores were related to the presence of an SRD diagnosis (rpb = .70, p < .0001) and diagnostic criteria for Antisocial Personality Disorder (r = .60, p < .0001). Stepwise regression revealed that (in order of magnitude) the presence of a substance‐abuse diagnosis followed by diagnostic criteria for Antisocial and Histrionic Personality Disorders were most related to MAC‐R scores (R = .78, R^2^ = .60). This indicates that the MAC‐R may be more related to the presence of an SRD than has been suggested, and when used in outpatient settings as MacAndrew (1965) intended, the MAC‐R may be useful as a screening device for assessing SRD among outpatients with Axis II psychopathology. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 801–813, 2001.