Even though transcranial direct current stimulation (tDCS) has the ability to reduce drug desire and attentional bias to drug-related stimuli, individual variations in these modulatory effects of tDCS were less well known. For a study, researchers sought to identify a cause of the inter-subject heterogeneity in tDCS effects that may be relevant to tDCS-based therapies for indivuduals with methamphetamine (MA) use disorder (IMUD).

A single session of either fake or genuine bilateral tDCS (anodal right/cathodal left) across the dorsolateral prefrontal cortex was given to 42 IMUD (all male). By measuring the EEG-derived P3 (a measure of early attentional bias) and late positive potential (LPP; a measure of sustained motivated attention) evoked by these stimuli, the effects of tDCS on MA desire and biased attention to drug stimuli were examined. The relationship between topological metrics, particularly those connected to information processing efficiency, and the tDCS impact were looked into in order to evaluate the relationship between changes in P3 and LPP and changes in the brain connectivity network (BCN) topology.

Following the tDCS session, the P3 amplitude considerably fell, but the amplitudes in the sham group rose. Changes in P3 amplitudes were substantially linked (r=-0.47, P=.03; r=-0.49, P=.02) with communication effectiveness as determined by BCN topological metrics. The tDCS treatment had no discernible impact on the LPP amplitude.

The results supported the hypothesis that tDCS reduced initial attentional bias to MA stimuli but not sustained motivated attention. The communication efficiency of the BCN topology may also play a role in the individual differences in the effects of tDCS. As a result, the BCN topology metrics may be able to accurately predict how well tDCS-based interventions will affect IMUD’s attentional bias to MA stimuli and craving for MA.

 

Reference: academic.oup.com/ijnp/article-abstract/25/8/631/6563479?redirectedFrom=fulltext