The United States leads the world in illicit opioid use and associated overdoses, morbidity, and mortality. Yet, for every fatal overdose in the current wave of fentanyl, speedballing, and xylazine-contaminated drugs, there are about 15 times as many non-fatal overdoses.
Recent studies estimate that 46% to 92% of people who use opioids illicitly either have experienced a non-fatal overdose or witnessed an overdose during their lifetime. Overdose survivors may suffer from undetected brain damage and hypoxic brain injury caused by opioid-induced respiratory depression.
There are several causes of brain hypoxia, including drowning, suffocation, cardiac arrest, stroke, and, now, nonfatal opioid overdose. It is known that many people have had a second chance; what is not known is how often a single or multiple overdoses compromise brain function and addiction recovery. Sadly, many overdose survivors don’t enter treatment or take medication-assisted treatments for their OUD. One key reason for such non-action could be unidentified post-overdose brain injury.
The Hippocampus and Brain Injury from Overdoses
Overdoses with counterfeit pills, cocaine, methamphetamine, xylazine, or heroin usually also include fentanyl, making neurologically compromising overdose more common. Studying fentanyl overdose is crucial because the may involve very low oxygen levels in the brain (hypoxia) or even a brief period of no oxygen (anoxia).
Hypoxic injury due to opioid overdose-related respiratory or heart failure is challenging for the brain's hippocampus and may result in hippocampal volume loss. The hippocampus, located in the brain's temporal lobe, is where memories are formed, indexed from specific life events, like where we had coffee with a friend last week.
Consider the rescue of a person who drowned or suffered a heart attack: The key is to keep blood and oxygen flowing to the brain to avert long-lasting memory loss and other consequences. Two recent studies have suggested hippocampal volume loss in non-fatal overdose may cause OUD-related amnesic syndrome.
James J. Mahoney III, Ph.D., a clinical neuropsychologist at West Vitginia University School of Medicine and the Rockefeller Neuroscience Institute, observes that fentanyl disrupts normal respiratory rhythm and negatively affects central and peripheral chemoreflex loops, causing severe and life-threatening respiratory........