Background: Increased attention bias toward drug-related cues over non-drug-related intrinsically pleasant reinforcers is a hallmark of drug addiction. In this study we used the late positive potential (LPP) to investigate whether such increased attention bias toward drug-related relative to non-drug-related cues changes over a protracted period of reduced drug use in treatment-seeking individuals with a cocaine use disorder (CUD).
Methods: Treatment-seeking individuals with CUD and matched healthy controls passively viewed a series of pleasant, neutral and drug-related pictures while their event-related potentials were recorded at baseline (≤ 3 weeks after treatment initiation) and at 6-month follow-up (only CUD).
Results: We included 19 treatment-seeking individuals with CUD and 18 matched controls in our analyses. The results showed a reversal in attention bias (i.e., LPP amplitude) from baseline (i.e., drug > pleasant) to follow-up (i.e., pleasant > drug) driven by an increased attentional engagement with pleasant pictures; this LPP reversal was paralleled by a concomitant reduction in self-reported wanting and craving for cocaine in the CUD group. Furthermore, reduced attention bias toward drug-related cues (relative to pleasant cues) was correlated with longer duration of abstinence at baseline, and the extent of its longitudinal reversal was correlated with decreased craving at follow-up, providing support for abstinence as a putative mechanism of this bottom-up attentional change.
Limitations: A limited sample size and the use of the same set of pictures at baseline and follow-up were the major limitations of this study.
Conclusion: Results collectively indicate that, by tracking with drug abstinence, LPP in response to drug-related relative to pleasant cues may serve as an indicator of clinical progress in treatment-seeking individuals with CUD.