The Millon adolescent clinical inventory and psychopathy.

We investigated the ability of the Millon Adolescent Clinical Inventory (MACI; Millon, 1993) to assess psychopathy as measured by the Psychopathy Checklist--Revised (PCL-R; Hare, 1991). Participants were 90 adolescents in an inpatient psychiatric unit. The MACI Substance Abuse Proneness (r = .47), Unruly (r = .43), and Submissive (r = -.42) scales correlated most strongly with the PCL-R. Using a discriminant function analysis, the Substance Abuse Proneness scale correctly distinguished between high- and low-psychopathy groups in 79% of cases. Using a rational approach, we developed a psychopathy content scale using 20 MACI items. This content scale correlated with the PCL-R (r = .60) and distinguished high- and low-psychopathy groups in 83% (kappa = .66) of cases (sensitivity = 85%, specificity = 81%).