The cognitie behaiioura mode of medica y unexp ained
symptoms: A theoretca and empirica reiiew (Deary, et a . 2007)
The artc e is a narratie reiiew of the theoretca standing and empirica eiidence for the cognitie
behaiiora mode of medica y unexp ained symptoms (MUS) in genera and for chronic fatgue
syndrome (CFS) and irritab e bowe syndrome (IBS) in partcu ar. iidence was found for genetc,
neuro ogica , psychophysio ogica , immuno ogica , persona ity, atentona , atributona , afectie,
behaiiora , socia and inter-persona factors in the onset and maintenance of MUS. The eiidence for
the contributon of indiiidua factors, and their autopoietc interacton in MUS (as hypothesised by
the cognitie behaiiora mode ) is examined. The eiidence from the treatment tria s of cognitie
behaiiora therapy for MUS, CFS and IBS is reiiewed as an experimenta test of the cognitie
behaiiora mode s. We conc ude that a broad y conceptua ized cognitie behaiiora mode of MUS
suggests a noie and p ausib e mechanism of symptom generaton and has heuristc ia ue. We ofer
suggestons for further research.
“The term medica y unexp ained symptoms names a predicament, not a specifc disorder”. In the
papers we haie reiiewed it is used in three oier apping ways:
(a) to refer to the occurrence of symptoms in the absence of obiious patho ogy;
(b) to refer to indiiidua c inica syndromes such as chronic fatgue syndrome (CFS) and irritab e
bowe syndrome (IBS);
(c) to refer to a subset of the DSM-IV somatoform disorders category.
Whi st c assifcaton remains disputed, there is consensus that a cognitie behaiiora therapy (CBT)
approach ofers a usefu exp anatory mode of MUS and an efectie treatment. From somatoform
disorders we exc uded hypochondriasis, coniersion, pain and body dysmorphic disorders.
Historica y, the c assica CBT mode of emotona distress as proposed by Beck distnguished
between its deie opmenta predispositons and precipitants, and its perpetuatng cognitie,
behaiiora , afectie and physio ogica factors (Beck, 1976). The CBT mode of MUS retains this
genera structure and its “three Ps”: predisposing, precipitatng and perpetuatng factors. Treatment
tends to inita y focus on the perpetuatng cyc e, atemptng to dismant e the se f-maintaining
inter ock of cognitie, behaiiora and physio ogica responses hypothesized to perpetuate the
symptoms. The approach is iery simi ar to Lang, Me amed, and Hart's (1970) three system mode of
fear maintenance and desensitzaton. The sine qua non of any CBT mode is a vicious circle, the
hypothesis that a self-perpetuatig iiteractii betweei difereit dimaiis maiitaiis symptims,
distress aid disability.
Predisposing factors
Genetics and earl experience: This is one of the east researched parts of the mode . There is some
eiidence for a genetc innuence in the deie opment of both unexp ained fatgue and somatzaton,
howeier this cou d simp y renect the expression of an inheritab e predispositon to genera distress.
There is a so some eiidence that certain types of ear y chi dhood eniironment increase the risk of
deie oping MUS. Hotopf (2003) reported that chi dhood experience of paterna i ness cou d be a risk
factor, and high ights the possibi ity that iicarious y earned i ness behaiior cou d ater serie to
perpetuate symptoms. A number of researchers haie reported eiidence that chi dhood adiersity in
the form of physica or sexua abuse is a risk factor for MUS in genera .
Neuroticism and somatops chic distress: Neurotcism (N) as a persona ity trait refers to a stab e
, ife ong tendency to experience negatie afect. Watson and Pennebaker (1989) suggested it be seen
not just as psycho ogica trait but as a more genera predispositon to experience “somatopsychic
distress.” There is a so good eiidence re atng N to both anxiety and depression; to heightened
reactiity to stressors; to increased incidence of objectie y measured negatie ife eients; and to
poor prognosis in depression. It is a so associated with increased incidence of physica i nesses such
as Asthma; poorer prognosis fo owing Coronary Heart Disease (CHD) and increased risk of cardiac
eients. N emerges from this data as being an important predictor not of specifc patho ogies, but of a
generic iu nerabi ity to physica i ness and psycho ogica distress. Giien the aboie it is hard y
surprising to fnd that high N is a so associated with MUS.
Perpetuating factors (factors that maintain or aggraiate symptoms)
The CBT mode proposes that cognitie and behaiiora factors interact with physica factors to
produce symptoms .
Sensitisation: refers to the tendency to haie a heightened response to stmu i because of prior
experience of them. For instance, in anima s the prior experience of stressfu stmu i ead to
increased physio ogica and behaiiora responses to future stressors, and to increased incidence of
physica patho ogy, partcu ar y if the inita stressors were uncontro ab e and unpredictab e.
Attention — cognitive activation and behavioral inhibition: Rief and Barsky (2005) noted that whi st
there is some eiidence that immune changes can induce behaiior change, it is “unc ear whether this
causa ity can a so be bi-directona and whether it contributes especia y to the deie opment and
maintenance of somatoform symptoms in humans.” Rief and Barsky (2005) proposed a more generic
mode in which symptoms arise through a two stage process of generaton and se ecton. At the frst
stage, bodi y symptoms may be generated by mu tp e determinants inc uding oier-arousa , chronic
stressors, HPA actiity, sensitsaton etc. At the second stage a hypothetca f ter system se ects
symptoms for conscious atenton. Brown (2004) has suggested a simi ar mode which emphasizes
the ro es of atenton, mis-atributon and mis-interpretaton in the maintenance of MUS.
It is to this “filter s stem” that we now turn. It is a notab e obseriaton that of a the sensatons
constant y processed by our bodies, iery few reach our conscious atenton. Most of the actiity of
our body is monitored and orchestrated unconscious y by more or ess automatc mechanisms. These
form the so-ca ed “cigiitve uiciisciius” which is the focus of the rapid y growing body of
psycho ogica research and theory known as embodied cognition. One of the key hypotheses of this
perspectie is that conscious awareness p ays iery it e part in our dai y actiites. Most y our body
and its processes run on automatc and remain experienta y transparent, passing be ow the radar of
atenton. Howeier occasiona y physio ogica or cognitie changes can bring to the foreground
processes and sensatons that wou d norma y escape notce. “Such hyper-renecton can generate a
body image that exaggerates proprioceptie and kinesthetc sensatons, and interferes with the
norma functoning of the norma y tacit body schema”.
Ursin (2005) noted that “cognitie bias is a higher form of sensitzaton… anxious peop e detect
fear re ated stmu i at a ower thresho d than norma contro s.” Ursin's mode is based on his noton
of a Cognitive Activation S stem (CAS)m which, in response to threat or stress, produces a state of
arousa “which is sustained unt the source of stress is e iminated” i.e. unt some instrumenta acton
is taken to dea with the stressor. This mode is simi ar to Gray's (1991) Behavioral Inhibition S stem
(BIS)m which was proposed to be specifca y oriented to aiersiie, fearfu and noie stmu i, producing
arousa , behaiiora inhibiton and se ectie atenton to the stmu i. In both mode s the frst functon
of the system is to stop other ongoing actiity and to reorganize atenton to the
threat/stressor/symptom. Pro onged actiaton of the CAT/BIS cou d serie to generate symptoms
through the physio ogica processes described aboie.
