Generalized anxiety disorder in women. A population-based twin study.
Little is known about the role of familial and genetic factors in the etiology of generalized anxiety disorder (GAD), a new disorder first proposed in DSM-III. We examine this question in 1033 female-female twin pairs from a population-based registry. Both members in each twin pair were "blindly" assessed by structured psychiatric interview. Our results suggest the following: (1) GAD is a moderately familial disorder; (2) the tendency for GAD to run in families seems to be due largely or entirely to genetic factors shared between relatives rather than to the effects of the familial environment; (3) the heritability of GAD, estimated at around 30%, is modest, with the remainder of the variance in liability resulting from environmental factors not shared by adult twins; (4) the heritability of GAD cannot be explained solely by the occurrence of GAD only during episodes of major depression or panic disorder; and (5) the etiologic role of genetic factors is probably similar in GAD with a 1- vs a 6-month minimum duration of illness.
Kendler
K S
KS
Department of Psychiatry, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298-0710.
Neale
M C
MC
Kessler
R C
RC
Heath
A C
AC
Eaves
L J
LJ
D000328:Adult; D000367:Age Factors; D001008:Anxiety Disorders / Q000453:epidemiology / Q000209:etiology / Q000235:genetics*; D015897:Comorbidity; D003866:Depressive Disorder / Q000453:epidemiology / Q000209:etiology / Q000235:genetics; D004200:Diseases in Twins / Q000453:epidemiology / Q000209:etiology / Q000235:genetics*; D005190:Family; D005260:Female; D006801:Humans; D008957:Models, Genetic; D016584:Panic Disorder / Q000453:epidemiology / Q000209:etiology / Q000235:genetics; D011247:Pregnancy; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012107:Research Design / Q000592:standards; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic