Officials in Massachusetts report a cluster of 14 patients who experienced sudden-onset amnesia, which they suspect was caused by opioids.
Thirteen of the patients reported current or past substance abuse, and 12 said they used opioids.
Six of the patients said they also used benzodiazepines, while another five said they had used cocaine, HealthDay reports. Report co-author Dr. Alfred DeMaria Jr. said the patients ranged in age from 19 to 52, making it unlikely their memory problems were due to a stroke or dementia.
Brain scans of the patients showed abnormalities that appeared to be caused by a toxic substance, the researchers report in the Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report. Most patients have improved over time, but two patients still had memory problems after one year. Even among those whose memories have improved, some patients continue to forget directions and other information just given to them.