Neuroticism as Consequence of Illness

Contrary to those who would like to tell you that CFS is caused by psychological problems, Dr. Goudsmit proves that it's the other way around -- being chronically ill can cause you to develop psychological problems.

Posted on behalf of Ellen Goudsmit (UK)

Neuroticism as a consequence of illness

Today, BMJ rapid responses (letters) published the study of patients with ME (Ramsay defined), MS and healthy controls showing that raised scores documented in the literature are almost certainly due to the duration of illness and the inclusion of five confounding items, e.g. questions asking about symptoms like dizziness and lethargy. The N score of the ME group was similar to that of the group with MS.

See http://www.bmj.com/cgi/eletters?lookup=by_date&days=1

Text:

We were interested in the findings from Hickie et al (1) that
neuroticism (N) scores, recorded shortly after diagnosis of a viral
infection, were not a risk factor for chronic fatigue syndrome (CFS)
at six and 12 months. This led us to re-examine the N scores we had
collected in 1987 from people with myalgic encephalomyelitis (ME), a
condition similar to and researched before the introduction of the
term CFS. We limited the statistical analysis to 48 patients who had
been diagnosed by physicians, who had been ill for at least six
months, were not taking psychotropic drugs and who had listed either
fatigue or muscle weakness following exertion as a main symptom. All
were recruited by a psychologist (EG) or through an advertisement in
the ME Association magazine. Participants were asked to complete the
Eysenck Personality Inventory (EPI) Form B (2) and to pass on a
second form to a close relative or friend of a similar age and
background, who could act as a healthy control. We also obtained N
scores from 50 patients with multiple sclerosis (MS), who were
recruited through various support groups.
The aims of this study were to measure neuroticism in patients with a
condition similar to those assessed by Hickie et al, to examine the
impact of time and to evaluate the influence of five items in the EPI
which enquired about somatic symptoms commonly reported by patients
with ME and CFS that might reflect disease rather than a personality
trait (items 16, 35, 38, 45, 47).
The mean N score of the ME group was 12.31 (SD 5.40), the mean of the
MS group was 14.24 (SD 4.78) and the mean of the healthy controls was
9.35 (SD 4.77). The difference between the three groups was highly
significant, F(2,143) =11.874, p<0.0005. However, post hoc analysis
using Tukey's HSD test found no significant difference between the
two patient groups (p=0.139). A similar pattern was observed when the
five somatic items were removed, although the effect was greater for
the groups with ME and MS than the controls (mean difference: 2.60,
2.34 versus .92 respectively). Using the revised scores, Tukey's HSD
test revealed a significant difference between the patients with MS
and controls (p<0.0005) and between the two patient groups (p=0.029)
but not between the ME group and controls (p=0.304). Thus while the N
scores were higher in the chronically ill groups, the omission of the
five items had the effect of reducing the difference between the ME
group and the controls, while increasing the difference between the
patients with ME and MS.
To assess the effect of the duration of illness, we compared the
scores of the patients who had been ill between 6 months and five
years with those who had been unwell for six years or more. The mean
N score for the former was 11.3 (SD 5.37), while that for the latter
was 15.29 (SD 4.30). The difference between the groups was
significant, both for N (t=2.3, p=0.028) and the revised scores
(t=2.19, p=0.036).
We conclude that raised neuroticism scores documented in ME and CFS (3) may reflect both the length of time which a patient has been ill,
and the inclusion of somatic items which confound the results.

References:
1. Hickie, I, Davenport T, Wakefield D, Vollmer-Conna, U, Cameron B,
Vernon, SD, et al. Post-infective and chronic fatigue syndromes
precipitated by viral and non-viral pathogens: prospective cohort
study. BMJ 2006; 333: 575
2. Eysenck HJ, Eysenck SB. Manual of the Eysenck personality
questionnaire. London: Hodder and Stoughton, 1964.
3. Buckley L., MacHale SM., Cavanagh JTO, Sharpe M., Deary IJ, Lawrie
SM. Personality dimensions inchronic fatigue syndrome and
depression. J Psychosom Res 1999; 46(4): 395-400.
Competing interests: None declared

Goudsmit, EM, Sneddon, P, Shepherd, C and Howes, S.