Early-onset alcoholism with conduct disorder: go/no go learning deficits, working memory capacity, and personality.
BACKGROUND
Two studies were conducted to investigate the disinhibitory mechanisms that (1) discriminate early-onset alcoholism (EOA) with conduct disorder (CD; antisocial EOA) from a non-antisocial subtype of EOA and (2) are associated with novelty-seeking and low harm avoidance.


METHODS
Young adults with antisocial EOA (n = 96), with non-antisocial EOA (without CD; n = 80), with CD alone (n = 50), and controls (n = 125) were given two go/no go tasks (one with monetary loss and the other with shock punishment), the Digit Span test (working memory capacity), and personality measures of harm avoidance, novelty-seeking/impulsivity, excitement-seeking, and negative affectivity.


RESULTS
Study 1 revealed that antisocial EOA subjects had poor behavioral inhibition compared with non-antisocial EOAs and controls on both go/no go tasks and with the CD-alone group on the monetary-loss task. Low Digit Span scores accentuated poor inhibition in antisocial EOAs on the monetary loss, but not the shock task. EOA with low Digit Span was associated with higher hit rates on the shock task. Study 2 revealed that antisocial EOAs had high novelty-seeking/impulsivity and low harm avoidance compared with both non-antisocial EOAs and controls. Low harm avoidance was associated with poor inhibition with shock punishment, and this association was mediated by CD. For subjects with low Digit Span scores, novelty-seeking/impulsivity was associated with poor inhibition to monetary-loss punishment and higher hit rates to shock punishment.


CONCLUSIONS
The results suggest two disinhibitory mechanisms that distinguish antisocial from non-antisocial EOA: an increased sensitivity to reward in nonaversive contexts associated with novelty-seeking/impulsivity and a decreased sensitivity to punishment in aversive contexts associated with low harm avoidance. Results also suggest that EOA and novelty-seeking/impulsivity are associated with a greater response to rewards in those with low working memory capacity.