Combining neurofeedback with swimming reduced image-induced craving in a small randomized study. The accompanying EEG changes did not establish that a particular frequency-band ratio caused the craving reduction.
Fadaei and colleagues allocated 32 methamphetamine-dependent patients to control, neurofeedback, swimming or combined neurofeedback/swimming groups. Resting EEG and visual-image-induced craving were assessed before and after intervention. This human treatment study examined patients during abstinence; it did not administer methamphetamine or measure the effects of a new drug dose.
The intervention groups showed changes in absolute EEG power across four frequency bands. Relative-power findings differed from absolute-power findings, and the combined group showed a higher delta-to-alpha ratio in selected comparisons. The combined group also had lower image-induced craving than control and either single intervention. Absolute power, relative power and a ratio are distinct quantities; an increase in one does not necessarily mean that every component increased.
The authors explicitly recognized that their data could not answer whether changing the delta/alpha ratio reduced craving. Establishing that mechanism would require a different experimental design. Small groups also limit precision and assessment of patient differences. Calling an EEG change ‘normalization’ requires care because statistical movement in a signal is not automatically restored everyday function. The study did not demonstrate long-term relapse prevention or validate an EEG cutoff for recovery. It supplies a preliminary combined-treatment finding and candidate physiological correlates, while leaving durability and the causal relationship between EEG and experience unresolved.
See why physiological and clinical treatment outcomes need separate comparisons for a different study and outcome.