Heritability of personality disorders in childhood: a preliminary investigation.

The heritability of personality disorder features was investigated in 112 child (ages 4-15 years) twin pairs (70 monozygotic and 42 dizygotic pairs). Parents assessed personality disorder features using the Coolidge Personality and Neuropsychological Inventory for Children (CPNI; Coolidge, 1998) that measures 12 personality disorders according to the criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (American Psychiatric Association, 1994). Structural equation model-fitting methods indicated that the median heritability coefficient for the 12 scales was .75 (ranging from .81 for the Dependent and Schizotypal Personality Disorder scales to .50 for the Paranoid and Passive-Aggressive Personality Disorder scales). These results suggest that childhood personality disorders have a substantial genetic component and that they are similar to heritability estimates of personality disorder traits in adults and counter hypotheses that only temperaments and higher-order personality disorder traits have significant genetic components (Paris, 1997).