Cognitive Improvement in Methamphetamine-Dependent Males: A Randomized Trial Comparing Different Exercise Interventions with Behavioral and fNIRS Evidence

Background: Long-term methamphetamine use disrupts brain function and impairs cognition. Currently, there is a lack of effective treatments for cognitive dysfunction in this population. This study aimed to investigate the effects of different exercise interventions on cognitive function and brain activation in methamphetamine-dependent individuals and to explore the potential neural mechanisms underlying cognitive improvement. Methods: In this randomized, assessor-blind, controlled study, 162 male methamphetamine-dependent individuals in compulsory isolation were randomly assigned to one of four groups: traditional regimen training (TR, n = 41), aerobic exercise (AE, n = 40), multimodal cognitive exercise training (MC, n = 40), and a control group (MA, n = 41). All participants completed an 8-week intervention. Cognitive function was assessed before and after the intervention using the Stroop task, while fNIRS was used to measure task-related hemodynamic responses. In addition, the Memory and Executive Screening (MES) and choice reaction time tests were used to evaluate cognitive and psychomotor performance. Results: After 8 weeks, traditional regimen training (p = 0.006), aerobic exercise (p = 0.024), and multimodal cognitive exercise training (p < 0.001) all significantly improved Stroop task accuracy. Aerobic exercise significantly increased activation in L-DLPFC (p = 0.044), R-DLPFC (p = 0.036), and L-FPA (p = 0.038), improved MES-T scores (p < 0.001) and shortened choice reaction time (p < 0.001). Traditional regimen training increased L-DLPFC activation (p = 0.026), improved MES-T scores (p < 0.001), and shortened choice reaction time (p < 0.001). Multimodal cognitive exercise training increased activation in L-DLPFC (p = 0.006), R-DLPFC (p = 0.014), and L-FPA (p = 0.002), improved MES-T scores (p < 0.001) and shortened choice reaction time (p < 0.001). Conclusions: Cognitive impairment in methamphetamine-dependent individuals may be associated with reduced prefrontal functional activity. Different exercise modalities produced different patterns of cognitive improvement and brain activation, with multimodal cognitive exercise training showing the largest overall benefit.