Externalizing behavior and emotion dysregulation are indicators of transmissible risk for substance use disorder.

BACKGROUND Psychological items discriminating children of fathers diagnosed with an illicit drug-related substance use disorder and normal controls are indicators of a unidimensional construct termed transmissible liability index (TLI) (Vanyukov et al., 2009). TLI is a highly heritable (Vanyukov et al., 2009; Hicks, Iacono, McGue, 2012) and valid (Vanyukov et al., 2009; Hicks et al., 2009; Kirisci et al., 2013a) measure of childhood liability to substance use disorders (SUDs). AIMS This longitudinal study determined whether TLI has incremental validity for predicting SUD beyond commonly measured psychological indicators of risk. METHODS TLI and measures of executive cognitive capacity, emotion dysregulation and externalizing disturbance were administered to boys at ages 10-12 and 16. SUD outcome determined at age 22 was assessed as (1) any SUD, (2) the number of drug-specific SUDs, and (3) SUD severity. RESULTS TLI predicted SUD beyond the contribution of measures of emotion dysregulation, executive cognitive capacity and externalizing disturbance. The association of emotion dysregulation and externalizing behavior at ages 10-12 and 16 with SUD at age 22 was also reduced to non-significance after controlling for transmissible risk measured by TLI. CONCLUSIONS TLI's incremental validity beyond these latter indicators of risk points to its utility for identifying vulnerable youths requiring intervention.