A twin study of depression and migraine: evidence for a shared genetic vulnerability.
OBJECTIVE
To determine if shared genetic or environmental vulnerabilities could underlie depression and migraine.


BACKGROUND
Depression and migraine headaches frequently coexist and their comorbidity may be due to shared etiologies.


METHODS
Female twins in the University of Washington Twin Registry responded to a mailed survey regarding their health history. Depression and migraine were determined by self-report of a physician's diagnosis. We used bivariate structural equation modeling to test for shared genetic, common environmental, and unique environmental components, and to estimate the magnitude of any shared component.


RESULTS
Among 758 monozygotic and 306 dizygotic female pairs, 23% reported depression and 20% reported migraine headaches. Heritability was estimated to be 58% (95% confidence interval: 48-67%) for depression and 44% (95% confidence interval: 32-56%) for migraine. Bivariate structural equation modeling estimated that 20% of the variability in depression and migraine headaches was due to shared genes and 4% was due to shared unique environmental factors.


CONCLUSIONS
The comorbidity of depression and migraine headache may be due in part to shared genetic risk factors. Research should focus attention on shared pathways, thereby making progress on 2 disease fronts simultaneously and perhaps providing clinicians with unified treatment strategies.
Schur
Ellen A
EA
Department of Medicine, University of Washington School of Medicine, Harborview Medical Center, 325 Ninth Avenue, Seattle, WA 98104, USA.
Noonan
Carolyn
C
Buchwald
Dedra
D
Goldberg
Jack
J
Afari
Niloofar
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003866:Depressive Disorder / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D004200:Diseases in Twins / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D012042:Registries; D014429:Twins, Dizygotic / Q000235:genetics / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics / Q000523:psychology; D055815:Young Adult