Research abstract:

Rethinking childhood adversity in chronic fatigue syndrome, by James E Clark, Sean L Davidson, Laura Maclachlan, Julia L Newton, Stuart Watson in Fatigue: Biomedicine, Health & Behavior [Published online: 10 Oct 2017]

Background:
Previous studies have consistently shown increased rates of childhood
adversity in chronic fatigue syndrome (CFS). However, such
aetiopathogenic studies of CFS are potentially confounded by
co-morbidity and misdiagnosis particularly with depression.

Purpose:
We examined the relationship between rates of childhood adversity using
two complimentary approaches (1) a sample of CFS patients who had no
lifetime history of depression and (2) a modelling approach.

Methods:
Childhood trauma questionnaire (CTQ) administered to a sample of 52
participants with chronic fatigue syndrome and 19 controls who did not
meet criteria for a psychiatric disorder (confirmed using the Structured
Clinical Interview for DSM-IV). Subsequently, Mediation Analysis (Baye’s
Rules) was used to establish the risk childhood adversity poses for CFS
with and without depression.

Results:
In a cohort of CFS patients with depression comprehensively excluded,
CTQ scores were markedly lower than in all previous studies and, in
contrast to these previous studies, not increased compared with healthy
controls. Post-hoc analysis showed that CTQ scores correlated with the
number of depressive symptoms during the lifetime worst period of low
mood. The probability of developing CFS given a history of childhood
trauma is 4%, a two-fold increased risk compared to the general
population. However, much of this risk is mediated by the concomitant
development of major depression.

Conclusions
The data suggests that previous studies showing a relationship between
childhood adversity and CFS may be attributable to the confounding
effects of co-morbid or misdiagnosed depressive disorder.

Keywords: Childhood adversity, chronic fatigue syndrome, modelling,
childhood trauma, depression