In 2001, the UK regulatory authority responsible for setting medical treatment standards updated its guideline for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) after reviewing hundreds of studies, concluding that ME/CFS is a neurological condition, not a psychogenic one. It banned treatments like psychotherapy and graded exercise therapy, which were found to be harmful. However, psychological and psychiatric groups objected, not on scientific grounds, but because it threatened their business. This resistance highlights a recurring problem where psychologists prioritise existing custom and practice over evidence and patient well-being, as tragically exemplified by the death of one young ME/CFS patient, who was repeatedly told her symptoms were ‘all in her mind’. Psychology’s dominant emphasis on individual agency, rather than on system-dependency, emboldens conservative scepticism toward liberal approaches to what are societally shared problems.