Monday, September 27, 2010

Psychiatric Misdiagnoses in Patients with CFS

May be reposted.

Here is David Sampson's comment on the recent Peter White et al paper entitled "Psychiatric misdiagnoses in patients with chronic fatigue syndrome" published in the JRSM Short Reports:

Re-   Peter White et al  (2010) Psychiatric misdiagnoses in patients with
chronic  fatigue syndrome :Tara Lawn1 ? Praveen Kumar1 ? Bernice Knight2 ?
Michael  Sharpe3 ? Peter D White4 on behalf of the PACE trial management
group (listed in  protocol reference). J R Soc Med Sh Rep 2010;1:28. DOI 

In this paper Professor White notes the high prevalence of  co-morbid
psychiatric illness in a cohort of CFS sufferers (56%) defined using  the Oxford
CFS Criteria and their under-diagnosis by clinicians in a secondary  care
specialist Chronic Fatigue Syndrome clinic.

The main question concerns the validity of employing the Oxford  CFS
criteria in this study. Rates of co-morbid psychiatric illness in ME/CFS patients
are known to be affected by diagnostic criteria  which clearly influence
patient selection (Jason, 2004).

In assessing the validity of the Oxford CFS  criteria it is interesting
that Professor White himself  noted in his original Lancet paper (White, 2001)
examining various CFS  criteria that: "both mood disorder at 2 months and
emotional personality  (neuroticism) predicted Oxford-defined CFS...These
predictions of CFS  were related more to having a co-morbid mood disorder than
to having CFS  itself".

What is of critical importance is the fact that the  strongest determinant
of an "Oxford defined CFS" are mood disorder and premorbid  psychiatric
disorder/GP attendance in year before onset- all of which are  predictors of
mood disorder/psychiatric illness quite independently of a fatigue syndrome
( see Sampson, 2010).

If such Oxford defined patients are ME/CFS patients who happen  to have developed depression/psychiatric illness subsequently to CFS itself then premorbid psychiatric history would not be such a potent predictor- however it is.

This demonstrates yet again that not only do such broad criteria  fail to
exclude patients with primary psychiatric diagnosis in the absence of 
physical symptoms (Stein 2005, Jason 1997, Sampson 2010) but that these  criteria
may be better at selecting such patients than ME/CFS patients  per se.

If both ME/CFS  and mood disorder/psychiatric illness were  synonymous this
would not matter- however they are not. The genetics of  ME/CFS, hypothalamic-pituitary-adrenal axis function, quantitive EEG and brain  blood flow on SPECT all differentiate between CFS and mood  disorder/depression (Stein, 2005).

This suggests that at very best the Oxford CFS criteria are  ambiguous and
at worst misleading and tautological in conception.

In fact as long ago as 2001 Professor  White noted in  his study examining
various ME/CFS criteria  "These data support the difference in nosology  and
aetiology between acute and chronic fatigue  syndromes (of relatively short
duration) and mood disorders.  They also suggests that the Oxford and CDC
criteria  for CFS should be used with caution or only  with stratification by
mood disorder  in aetiological studies".

David Sampson BSC(Hons),MSc,MBPsychS


Jason L. et al.  (2004) Comparing the Fukuda et al Criteria and the 
Canadian Case definition for Chronic Fatigue Syndrome. Journal of Chronic  Fatigue
Syndrome ,12, 37-52.

White P. et al. (2001); Lancet, Vol. 358, N.9297; pp 1946-1953  Predictions
and associations of fatigue syndromes and mood disorders that occur  after
infectious mononucleosis.

Sampson D.P. (2010)  Close Analysis of a Large Published  Trial Into
Fatigue Syndromes and Mood Disorders That Occur After Documented  Viral Infection.
Bulletin of the IACFS/ME, Vol 18,Issue 2, Summer  2010.

Stein E (2005). Chronic Fatigue Syndrome: Assessment and  Treatment of
Patients with ME/CFS: Clinical Guidelines for  Psychiatrists.

Jason L. (1997). Politics, Science, and the Emergence of a New  Disease:
The Case of Chronic Fatigue Syndrome, American Psychologist; Vol. 52,  No. 9,

No comments: