An article from the American Psychological Association, that quotes Sharpe. (2013.) When symptoms are a mystery. https://www.apa.org/monitor/2013/07-08/symptoms "There has been an unfortunate split in our thinking between what's physical and what we think of as ‘real,' and what is mental, and what we think of as imaginary or blameworthy," says Sharpe. "What we really don't have, and what we need, is better integration and understanding of conditions that may have both physical and psychological components." In fact, because of this split, the area is highly controversial, with physicians and researchers sometimes butting heads with patient advocates who are unwilling to accept that their conditions may be partly or completely psychologically based. "Finally, some studies show that antidepressants can help ameliorate a gamut of unexplained symptoms, whether or not the person is depressed, says Sharpe. That could be because depression increases the propensity to ruminate and to view stimuli as aversive, because the neural pathways for negative psychological and physical symptoms such as pain and depression are closely related, or both, he notes."