Compared to serotonin, dopamine and noradrenaline, an endorphin deficiency or dysfunction is actually rather rare, in the absence of opiate use. However I believe there may be a key exception to this. I think that adults who experienced chronic or acute stress as a child may be at increased risk of endorphin system dysfunction later in life. As endorphins are key stress-fighters, there is a chance that someone’s endogenous opioid system could become dysfunctional after intense demands are put on it through severe or long-lasting stress.
