I found MacHale et al's (Reference Mac Hale, Lawrie and Cavanagh2000) discussion of their results confusing. According to the abstract and methods, they screened their patients with chronic fatigue syndrome (CFS) to exclude those with depression. Then they examined this group further using a standardised psychiatric interview (Schedule for Affective Disorders and Schizophrenia), in order to “ exclude subjects with current psychiatric illness, with a particular emphasis on depression”. The data from the Hamilton Rating Scale for Depression are difficult to interpret given the number of illnessrated items, but the scores did not indicate a significant degree of depression either. So, having excluded “subjects with depression or anxiety”, why did the authors claim in their discussion that “the main limitation of the present study is that our CFS subjects had high levels of depression”?

If this is correct, why was their depression not picked up by the three measures? Why were these patients not excluded from the research as stated by the authors or, funds permitting, used as a comparison group (Reference Costa, Tannock and BrostoffCosta et al, 1995; Reference Fischler, Flamen and EveraertFischler et al, 1998)? How depressed were the 10 patients on antidepressants and, if these were not effective, could their suboptimal treatment have contributed to their ongoing fatigue?

I was also baffled by the authors' suggestion that the thalamic hyperperfusion may reflect “increased attention to motor and cognitive tasks”. What were the patients doing? The abstract states that the scans were conducted at rest. If the subjects had just completed a battery of cognitive tests, why did the authors not check to see whether the data available supported their hypothesis (Reference Fischler, Flamen and EveraertFischler et al, 1998)?

If this paper was subjected to peer review, why did no one query the selective discussion of the findings and the misrepresentation of the literature on CFS and psychopathology?