Resting EEG patterns differed between people with methamphetamine use disorder and controls in a microstate study. These group differences did not validate a test for diagnosing intoxication or determining an individual’s cognitive impairment.
Chen and colleagues analyzed 55 patients with methamphetamine use disorder and 27 matched healthy controls. A 64-channel EEG recorded resting activity, and the analysis grouped recurring scalp topographies into microstate classes. The researchers compared their durations and explained variance and explored relationships with cognitive measures and reported drug history. This was human observational research, not experimental methamphetamine dosing.
The patient group had shorter mean durations of classes A and B and greater global explained variance for class C. Current-source estimates also differed in selected microstates. Regression analyses related some parameters to use frequency, working-memory testing and drug-word errors. These measures describe temporal properties of electrical patterns. Global explained variance is not the percentage of the brain that is damaged, and a shorter state does not by itself identify why the pattern changed.
The sample was relatively small, and correlations cannot determine whether a pattern preceded drug use or resulted from it. Microstate classes are analytical groupings, while source localization relies on modeling; neither is direct observation of a specific psychological process. The study did not establish sensitivity, specificity or a clinical threshold for classifying an individual. A history association also cannot date ingestion or quantify impairment at an earlier event. The work offers research candidates for studying network dynamics, with clinical utility requiring replication and prospective validation against a clearly specified diagnostic or functional outcome.
See EEG differences despite nonsignificant behavioral comparisons.