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Reply to Dolphin
The theme White advances against lumping into a single functional somatic syndrome could also be made against his support for broad heterogeneous chronic fatigue!
This was a sloppy assumption of my behalf from when they said: "This remained true even though we modified the standardized interview to exclude fatigue and used questionnaires that avoided the somatic symptoms associated with psychiatric disorder and chronic fatigue syndrome."
Exactly, they only adjust rates for depression and do not adjust rates for anxiety disorders. That's when I wondered about dysautonomia etc.
GHQ-12 looks somewhat problematic. HADS is even worse if a single question can make all the difference, see this earlier smaller study mentioned in Hooper's "Organic evidence for Gibson":
- A single item on the HAD depression scale refers to feeling slowed down. Not surprisingly, this was cited by all patients. When this single item was removed from analysis, no patient retained a rating of depression. This emphasised the importance of possible false positive diagnosis of depression on the basis of somatic symptoms
- Wessely and Powell (JNNP 1989:52:940-948) found the total psychiatric morbidity in (ME)CFS was 72% ---other studies have found it to be 21%. (Our) study finds a variable prevalence depending on the criteria used. This emphasised the ease with which psychiatric rating scales may lead to false positive diagnoses in patients with physical symptoms
The study's abstract on PubMed mentions additional problems with other scales: "Psychological distress, measured by simple psychiatric rating scales was common, but specific psychiatric diagnoses, derived from a comprehensive diagnostic interview, occurred less frequently. One questionnaire (Montgomery-Asberg depression rating scale) found emotional distress in 93%, but the diagnostic instrument (Present State Examination) suggested depressive syndromes in only two patients (13%)."
I wonder if Wessely et al's later study compensated for the "feeling slowed down" question?
From the Australian 2002 guidelines for CFS (about adolescents): "When somatic symptoms characteristic of CFS are excluded from the commonly used depression scales, only a small proportion have major depression with anhedonia (7%)." I think they are citing this study but I can't access it so I don't know what scales they used.
As we have been discussing off topic, the fundamental problems with, and overlap between, CFS diagnosis and psychiatric measurements, causes many false positives. Are there any accurate scales at all or is the more involved SCID the only apparently reliable method?
White has written against the idea that there is one Functional Somatic Syndrome: http://bjp.rcpsych.org/cgi/content/full/185/2/95
The theme White advances against lumping into a single functional somatic syndrome could also be made against his support for broad heterogeneous chronic fatigue!
Wessely et al may claim that accounted for the CFS symptoms by the choice of questionnaires and excluding fatigue but as oceanblue points out the CIS-R questionnaire is problematic for diagnosing psychiatric disorder in CFS even without fatigue.
As you say there may be problems with other categories of the CIS-R (and other questionnaires) also because of dysautonomia and inflammation.
I have read the paper now and can see no mention that the 8 CDC symptoms were excluded from CIS-R scores.
This was a sloppy assumption of my behalf from when they said: "This remained true even though we modified the standardized interview to exclude fatigue and used questionnaires that avoided the somatic symptoms associated with psychiatric disorder and chronic fatigue syndrome."
And with the HAD questionnaire, they did some calculations with a fatigue question and some without but didn't exclude any other questions: "Of the 36 subjects with chronic fatigue syndrome, 29 (80.6%) had probable and 17 (47.2%) had definite depression according to the Hospital Anxiety and Depression Scale subscale. These proportions fell to 16 (44.4%) and 10 (27.8%) when the fatigue question was excluded. Twenty-four (66.7%) had probable and 19 (52.8%) had definite anxiety disorders."
Exactly, they only adjust rates for depression and do not adjust rates for anxiety disorders. That's when I wondered about dysautonomia etc.
Anyway, I thought I'd also post the questions for the GHQ-12 which Wessely et al said was not problematic for CFS in terms of diagnosing psychiatric disorders.
GHQ-12 looks somewhat problematic. HADS is even worse if a single question can make all the difference, see this earlier smaller study mentioned in Hooper's "Organic evidence for Gibson":
- A single item on the HAD depression scale refers to feeling slowed down. Not surprisingly, this was cited by all patients. When this single item was removed from analysis, no patient retained a rating of depression. This emphasised the importance of possible false positive diagnosis of depression on the basis of somatic symptoms
- Wessely and Powell (JNNP 1989:52:940-948) found the total psychiatric morbidity in (ME)CFS was 72% ---other studies have found it to be 21%. (Our) study finds a variable prevalence depending on the criteria used. This emphasised the ease with which psychiatric rating scales may lead to false positive diagnoses in patients with physical symptoms
The study's abstract on PubMed mentions additional problems with other scales: "Psychological distress, measured by simple psychiatric rating scales was common, but specific psychiatric diagnoses, derived from a comprehensive diagnostic interview, occurred less frequently. One questionnaire (Montgomery-Asberg depression rating scale) found emotional distress in 93%, but the diagnostic instrument (Present State Examination) suggested depressive syndromes in only two patients (13%)."
I wonder if Wessely et al's later study compensated for the "feeling slowed down" question?
From the Australian 2002 guidelines for CFS (about adolescents): "When somatic symptoms characteristic of CFS are excluded from the commonly used depression scales, only a small proportion have major depression with anhedonia (7%)." I think they are citing this study but I can't access it so I don't know what scales they used.
As we have been discussing off topic, the fundamental problems with, and overlap between, CFS diagnosis and psychiatric measurements, causes many false positives. Are there any accurate scales at all or is the more involved SCID the only apparently reliable method?