Conscientiousness is modified by genetic variation in catechol-O-methyltransferase to reduce symptom complaints in IBS patients.
BACKGROUND
Attention to and perception of physical sensations and somatic states can significantly influence reporting of complaints and symptoms in the context of clinical care and randomized trials. Although anxiety and high neuroticism are known to increase the frequency and severity of complaints, it is not known if other personality dimensions or genes associated with cognitive function or sympathetic tone can influence complaints. Genetic variation in catechol-O-methyltransferase (COMT) is associated with anxiety, personality, pain, and response to placebo treatment. We hypothesized that the association of complaint reporting with personality might be modified by variation in the COMT val158met genotype.


METHODS
We administered a standard 25-item complaint survey weekly over 3-weeks to a convenience sample of 187 irritable bowel syndrome patients enrolled in a placebo intervention trial and conducted a repeated measures analysis.


RESULTS
We found that complaint severity rating, our primary outcome, was negatively associated with the personality measures of conscientiousness (β = -0.31 SE 0.11, P = 0.003) and agreeableness (β = -0.38 SE 0.12, P = 0.002) and was positively associated with neuroticism (β = 0.24 SE 0.09, P = 0.005) and anxiety (β = 0.48 SE 0.09, P < 0.0001). We also found a significant interaction effect of COMT met alleles (β = -32.5 SE 14.1, P = 0.021). in patients genotyped for COMT val158met (N  = 87) specifically COMT × conscientiousness (β = 0.73 SE 0.26, P = 0.0042) and COMT × anxiety (β = -0.42 SE 0.16, P = 0.0078) interaction effects.


CONCLUSIONS
These findings potentially broaden our understanding of the factors underlying clinical complaints to include the personality dimension of conscientiousness and its modification by COMT.
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts.
Kathryn T
KT
Hall
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts.
Benjamin R
BR
Tolkin
Department of Medicine, Massachusetts General Hospital and Harvard Medical School Boston, Massachusetts.
Garrett M
GM
Chinn
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; School of Psychology, University of Plymouth Devon, UK.
Irving
I
Kirsch
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School Boston, Massachusetts ; Endicott College Beverly, Massachusetts.
John M
JM
Kelley
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; Department of Gastroenterology, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts.
Anthony J
AJ
Lembo
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts.
Ted J
TJ
Kaptchuk
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; Department of Gastroenterology, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts.
Efi
E
Kokkotou
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts.
Roger B
RB
Davis
Program in Placebo Studies, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts ; Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts.
Lisa A
LA
Conboy
D000328:Adult; D001007:Anxiety / Q000150:complications / Q000235:genetics; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications / Q000235:genetics / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D010551:Personality / Q000235:genetics; D010919:Placebos
D010919:Placebos; D002394:Catechol O-Methyltransferase
COMT; Catechol-O-methyltransferase; complaints; conscientiousness; personality