A multidimensional model of psychobiological interactions in functional dyspepsia: a structural equation modelling approach.
OBJECTIVE
Gastric sensorimotor function, abuse history, 'trait' and 'state' psychological factors and 'somatisation' all play a role in functional dyspepsia (FD) and its associated impaired quality of life (QoL), but their interplay remains poorly understood. We aimed to test a comprehensive, a priori hypothesised model of interactions between these dimensions in FD.


METHODS
In 259 FD patients, we studied gastric sensitivity with a barostat. We measured abuse history (sexual/physical, childhood/adulthood), 'trait' (alexithymia, trait anxiety) and 'state' (positive/negative affect, depression, panic disorder) psychological factors, somatic symptom reporting (somatic symptom count, dyspepsia, irritable bowel syndrome and fatigue symptoms) and QoL (physical, mental) using validated questionnaires. Confirmatory factor analysis (CFA) was used to assess whether four a priori hypothesised latent variables ('abuse', 'trait affectivity', 'state affect' and 'somatic symptom reporting') were adequately supported by the data. Structural equation modelling (SEM) was used to test the a priori hypothesised relationships between these latent variables and the observed variables gastric sensitivity and QoL.


RESULTS
Both the CFA and SEM models fitted the data adequately. Abuse exerted its effect directly on 'somatic symptom reporting', rather than indirectly through psychological factors. A reciprocal relationship between 'somatic symptom reporting' and 'state affect' was found. Gastric sensitivity influences 'somatic symptom reporting' but not vice versa. 'Somatic symptom reporting' and 'trait affectivity' are the main determinants of physical and mental QoL, respectively.


CONCLUSIONS
We present the first comprehensive model elucidating the complex interactions between multiple dimensions (gastric sensitivity, abuse history, 'state' and 'trait' psychological factors, somatic symptom reporting and QoL) in FD.
Department of Psychology, Macquarie University, Sydney, Australia.
Michael P
MP
Jones
Eline
E
Coppens
Rita
R
Vos
Lieselot
L
Holvoet
Patrick
P
Luyten
Jan
J
Tack
Lukas
L
Van Oudenhove
D000328:Adult; D000342:Affective Symptoms / Q000523:psychology; D000368:Aged; D001007:Anxiety / Q000523:psychology; D003863:Depression / Q000523:psychology; D017579:Domestic Violence / Q000523:psychology; D004415:Dyspepsia / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D017288:Pain Threshold / Q000502:physiology; D016584:Panic Disorder / Q000523:psychology; D010812:Physical Stimulation / Q000379:methods; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D011788:Quality of Life; D012677:Sensation / Q000502:physiology; D013001:Somatoform Disorders / Q000503:physiopathology / Q000523:psychology*; D013270:Stomach / Q000503:physiopathology