Association between aperiodic activity and impulsivity in individuals with methamphetamine use disorder

Methamphetamine use disorder (MUD) poses significant public health risks, with individuals often exhibiting heightened impulsivity. Traditional electroencephalography (EEG) spectral analyses have yielded inconsistent findings, potentially due to the conflation of periodic and aperiodic activities. The aperiodic component, quantified by the exponent and offset parameters, reflects excitatory/inhibitory (E/I) balance and broadband neural activity, which may be disrupted in addiction. However, its association with impulsivity in MUD remains unexplored.

This study aimed to examine aperiodic activity in individuals with MUD and its correlation with impulsivity, using the FOOOF algorithm to decompose EEG signals.

The study included 47 male MUD patients and 41 healthy male controls. Resting-state EEG was recorded, and aperiodic components (exponent and offset) were extracted via the FOOOF algorithm. Clinical assessments included the Barratt Impulsiveness Scale (BIS-11), Zung Self-Rating Anxiety/Depression Scales, and visual analogue scales for craving.

The aperiodic exponent (t = 3.617, p < 0.001) and offset (t = 2.762, p = 0.007) were significantly reduced in the MUD group compared to controls. Both parameters showed negative correlations with impulsivity measures (e.g., exponent vs. BIS-11 total score: r = -0.345, p = 0.019; offset vs. BIS-11 total: r = -0.389, p = 0.008) and years of methamphetamine use (exponent: r = -0.394, p = 0.023).

Reduced aperiodic activity in MUD suggests E/I imbalance, likely associated with dopaminergic dysfunction. The correlations with impulsivity highlight the potential of aperiodic components as biomarkers for behavioral dysregulation in addiction. These findings underscore the transdiagnostic relevance of E/I balance in impulse control.