The present study evaluated the heritability of personality traits and psychopathology symptoms assessed by the Minnesota Multiphasic Personality Interview 2nd edition (MMPI-2) in a family-based sample selected for alcohol dependence. Participants included 950 probands and 1204 first-degree relatives recruited for the UCSF Family Alcoholism Study. Heritability estimates (h2) for MMPI-2 scales ranged from .25β.49. When alcohol dependence was used as a covariate, heritability estimates remained significant but generally declined. However, when the MMPI-2 scales were used as covariates to estimate the heritability of alcohol dependence, scales measuring antisocial behavior (ASP), depressive symptoms (DEP), and addictive behavior (MAC-R) led to moderate increases in the heritability of alcohol dependence. This suggests that the ASP, DEP, and MAC-R scales may explain some of the non-genetic variance in the alcohol dependence diagnosis in this population when utilized as covariates, and thus may serve to produce a more homogeneous and heritable alcohol dependence phenotype
