Reduced interhemispheric executive control network coupling in men during early cocaine abstinence: A pilot study

- Interhemispheric executive control network (ECN) coupling declines in cocaine abstinence.
- Coupling correlates were strongest in the prefrontal subregion of the ECN.
- Lower cocaine metabolite concentrations were correlated with less ECN coupling.

BackgroundIndividuals who use cocaine have fewer cognitive resources needed to maintain abstinence. This is evidenced by blunted brain function during cognitive control tasks and reduced communication between brain regions associated with cognitive function. For instance, relapse vulnerability is heightened in individuals with less communication between the right and left frontoparietal executive control network (ECN). Given that recent cocaine use enhances such communication, it is plausible that recency of cocaine use influences interhemispheric ECN communication. However, it is unclear whether ECN communication weakens over the course of early cocaine abstinence, which may then enhance relapse risk.MethodsIn ten men with cocaine use disorder, we conducted a preliminary assessment of the relationship between the number of days since last cocaine use (1-3 days) and interhemispheric ECN coupling using resting state functional magnetic resonance imaging (fMRI).ResultsReduced interhemispheric ECN coupling was associated with increasing days since last cocaine use; weaker coupling was also associated with lower urine cocaine metabolite concentrations. This association was more prominent in prefrontal than parietal ECN-subregions.ConclusionsPreliminary results indicate that resting state interhemispheric ECN coupling weakens within the first few days following last cocaine use. Because of the known link between reduced ECN interhemispheric coupling and relapse vulnerability, these results suggest that relapse risk may increase the longer an individual abstains during an early quit attempt. Treatments focused on reversing this coupling deficit may facilitate abstinence.