At first glance, this was not so surprising. Of course, patients in pain are stressed, and show greater biological expression of neurobiological stress changes. What is a little less obvious but no less true is the converse, that anxious patients are more susceptible to chronic pain.
But the study may suggest an explanation for one clinically puzzling fact — that even though they have markedly different modes of action in the CNS, abusers of opiates and of benzodiazepine anti-anxiety medications often find their appeal interchangeable.
Source: Neurosciencestuff Tumblr