The dopamine-4 receptor gene associated with binge eating and weight gain in women with seasonal affective disorder: an evolutionary perspective.
BACKGROUND
We recently described a preliminary association between the hypofunctional seven-repeat allele of the dopamine-4 receptor gene (DRD4) and increased maximal lifetime body mass index in women with seasonal affective disorder (SAD). In this study, we examined whether binge eating behavior mediated this putative association.


METHODS
The study sample consisted of 131 women with winter SAD who reported increased intake of high-carbohydrate/high-fat foods during depressive episodes. We compared rates of binge eating behavior in the two genotypic groups defined by the presence or absence of the seven-repeat allele of DRD4.


RESULTS
Consistent with our working hypothesis, the proportion of binge eaters was significantly greater in probands with the seven-repeat allele (18 of 46, 39.1%) than in probands without this allele (14 of 85, 16.5%) [chi(2)(1)= 8.32, p = .004; odds ratio = 3.25, 95% confidence interval 1.43, 7.41].


CONCLUSIONS
Pending replication in other samples, these results point to a genetic factor that could help in the early identification and treatment of women at higher risk for seasonal weight gain associated with binge eating behavior. At a theoretic level, the current results suggest a novel link between evolutionary models of seasonal weight gain on the one hand and the DRD4 gene on the other.
Levitan
Robert D
RD
Mood and Anxiety Division, Centre for Addiction and Mental Health, University of Toronto, Department of Psychiatry, 250 College Street, Room 1126, Toronto, Ontario M5T 1R8, Canada. robert_levitan@camh.net
Masellis
Mario
M
Basile
Vincenzo S
VS
Lam
Raymond W
RW
Kaplan
Allan S
AS
Davis
Caroline
C
Muglia
Pierandrea
P
Mackenzie
Bronwyn
B
Tharmalingam
Subi
S
Kennedy
Sidney H
SH
Macciardi
Fabio
F
Kennedy
James L
JL
D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D015992:Body Mass Index; D002032:Bulimia / Q000097:blood / Q000209:etiology / Q000235:genetics*; D016009:Chi-Square Distribution; D005260:Female; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D008875:Middle Aged; D016017:Odds Ratio; D011569:Psychiatric Status Rating Scales; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050638:Receptors, Dopamine D4; D016574:Seasonal Affective Disorder / Q000097:blood / Q000150:complications / Q000235:genetics*; D020080:Tandem Repeat Sequences / Q000235:genetics; D015430:Weight Gain / Q000235:genetics*
C493599:DRD4 protein, human; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4