It is interesting to see that article in the BMJ and see the reference to SSD
In DSM-5, the focus shifted to “excessive” responses to distressing, chronic, somatic symptoms with associated “dysfunctional thoughts, feelings, or behaviours.”
That looks suspiciously like the "dysfunctional cognitions and maladaptive behaviour" which Wessely et al decided was fundamental to ME in, I think it was, 1991.