Neural mechanisms of affective instability and cognitive control in substance use.

OBJECTIVE

We explored the impact of affect on cognitive control as this relates to individual differences in affective instability and substance use. Toward this end, we examined how different dimensions of affective instability interact to predict substance misuse and the effect of this on two event-related potential components, the reward positivity and the late positive potential, which are said to reflect the neural mechanisms of reward and emotion processing, respectively.

METHODS

We recorded the ongoing electroencephalogram from undergraduate students as they navigated two T-maze tasks in search of rewards. One of the tasks included neutral, pleasant, and unpleasant pictures from the International Affective Picture System. Participants also completed several questionnaires pertaining to substance use and personality.

RESULTS

A principal components analysis revealed a factor related to affective instability, which we named reactivity. This factor significantly predicted increased substance use. Individuals reporting higher levels of affective reactivity also displayed a larger reward positivity following stimuli with emotional content.

CONCLUSION

The current study uncovered a group of high-risk substance users who were characterized by greater levels of affective reactivity and context-specific increased sensitivity to rewards.

SIGNIFICANCE

These results help to elucidate the complex factors underlying substance use and may facilitate the creation of individually-tailored treatment programs for those struggling with substance use disorders.