Objective: Chronic alcoholics with a comorbid diagnosis of antisocial personality (ASP) symptomatology often exhibit early onset, severe course, and poor treatment outcomes. In addition, antisocial characteristics have been associated with a variety of cognitive deficits, including abnormalities of semantic processing, a deficit also found in alcoholics. Using the N400 task, this study investigated whether comorbid ASP symptomatology in alcoholics and community controls contributes to deficits in cognitive efficiency.
Method: The N400 component of the event-related potential was elicited in detoxified alcoholics (n = 71; 56 male) and community controls (n = 36; 22 female) by sentences with congruent, related/incongruent or unrelated/incongruent terminal words. Difference waveforms were derived, and both amplitude and latency measures were obtained. Antisocial personality symptomatology was assessed using the ASP section of the Diagnostic Interview Schedule IV.
Results: Data were analyzed via linear regression using alcoholism, ASP positive (ASP+) status and their interaction term as predictors of N400 amplitude and latency. Significant latency findings were noted in the related/incongruent sentence condition. Increased N400 latency was predicted by ASP+ status at electrode site Pz (p = .01). The interaction of alcoholism and ASP+ status predicted increased N400 latency at electrode site P4 (p = .009), with ASP+ alcoholics demonstrating the greatest latency.
Conclusions: The presence of N400 latency differences in response to related/incongruent semantic information in the current study differs from previous findings in studies of chronic alcoholism that do not account for ASP. These data suggest that antisocial personality disorder and alcoholism may affect cognitive function via different underlying mechanisms.