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6. SUBSTANCE MISUSE AND EEG/BEHAVIORAL CORRELATES OF RESPONSE INHIBITION: ETIOLOGICAL INSIGHTS FROM A COTWIN CONTROL DESIGN
Deficits in inhibitory control are a core component of substance misuse and addiction. Alcohol and nicotine use are negatively associated with midfrontal theta during response inhibition. It is unclear whether this reflects a premorbid determinant or potential consequence of substance misuse. We assessed the relationship between problematic alcohol/nicotine misuse across emerging adulthood and theta-band EEG dynamics during a Go/Nogo task in a sample of 638 same-sex twins (age: M [SD] = 24.4 [0.8]; 346 women). A cotwin control (CTC) analysis differentiated alcohol/nicotine exposure effects from preexisting risk. Decreased nogo theta power was associated with greater drinking, number of hangovers/blackouts/binges, and cigarettes per day (CPD). As hypothesized given prior work, effects were only significant in women. CTC analysis indicated that within a twin pair, the heavier-using twin had lower theta compared to her lesser-using cotwin, suggesting an exposure-related effect of alcohol and nicotine misuse on nogo-related theta. There was also evidence of familial confounding between theta and drinking. Worse task performance (lower d-prime scores; greater false alarms) was linked to increased CPD in men and women and likely reflected a premorbid vulnerability. Problematic alcohol and nicotine use during emerging adulthood may have sex-specific substance exposure-related effects on frontal inhibition-related theta dynamics.
Funding: DA036216; Eva O. Miller Fellowship (University of Minnesota).