Scientists find molecular reason for creation of chronic pain

A new study finds the exact molecular mechanism that turns acute pain into chronic pain – a condition that leads to the use of opioids and often, lifelong addiction

The study, led by University of California Irvine, finds that a specific molecular mechanism controls how acute pain becomes chronic pain.

Chronic pain evolves from acute pain caused by the physical trauma of tissue damage due to surgery or injury and is a massive problem, affecting more than 1.5 billion people worldwide.

It continues long past tissue healing, is often resistant to therapy, and remains seriously undertreated.

“Chronic pain is experienced on many levels beyond just the physical, and this research demonstrates the biological basis of affective pain. It is a powerful reminder that psychological phenomena such as affective pain are the result of biological processes,” said Dr Nora D Volkow, not involved in this study.

So, how did scientists stop the creation of chronic pain?

Essentially, disabling N-acylethanolamine acid amidase (NAAA)—an intracellular enzyme–in the spinal cord during a 72-hour time window following peripheral tissue injury literally stops chronic pain development, in all genders of mice.

This information could change how medicines work. It could also mean that people are spared the lifelong experience of chronic pain, if medical intervention is done soon enough.

Professor Piomelli says discovery is previously “unrecognised”

“Delineating the nature, localization and timing of the events involved in pain chronicity is necessary to pinpointing control nodes in the process that can be targeted by new classes of disease-modifying medicines beyond analgesics,” said Daniele Piomelli, Distinguished Professor in the UCI School of Medicine Department of Anatomy & Neurobiology.

“This study is the first to identify that NAAA, a previously unrecognized control node, can be effectively targeted by small-molecule therapeutics that inhibit this enzyme, and block the transition from acute to chronic pain.”

For some, this discovery could mean averting a future of addiction to opioids. Opioids, prescribed often to deal with this kind of pain, can lead to addiction. The opioid epidemic, unfolding in the shadows of societal awareness, is connected to issues such as access to healthcare and the HIV epidemic.

If scientists can figure out how to adapt their node discovery into treatment, the future of both pain and addiction will significantly change.

Read the full study here.