Genetic and environmental effects on self-reported depressive symptoms in a general population twin sample.
To determine the etiology of self-reported depressive symptoms and their co-occurrence in the general population, multivariate genetic models were fitted to the responses of 771 female twin pairs (463 MZ, 308 DZ) to a 20-item epidemiological depression inventory (CES-D scale). A model which contained one common genetic factor, one shared environmental factor, and four unique environmental factors provided a useful account of symptom covariation. Under this model, the four non-shared environmental factors explained the largest proportion of variance in response to the CES-D scale, whereas a single common genetic factor explained substantially less of the variation in symptomatology. Consistent with previous findings (Kendler, Heath, Martin, & Eaves, Archives of General Psychiatry 43, 213-221, 1986) shared environmental influences were found to play a relatively minor role in the report of depressive symptoms. These results suggest that while genetic factors do contribute to the covariation among symptoms of depression, it is the largely non-shared environmental factors that account for the co-occurrence of symptoms in the general population.
Silberg
J L
JL
Department of Human Genetics, Medical College of Virginia, Richmond 23298-0033.
Heath
A C
AC
Kessler
R
R
Neale
M C
MC
Meyer
J M
JM
Eaves
L J
LJ
Kendler
K S
KS
D000293:Adolescent; D000328:Adult; D003866:Depressive Disorder / Q000235:genetics* / Q000523:psychology; D004200:Diseases in Twins / Q000235:genetics* / Q000523:psychology; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D006801:Humans; D008875:Middle Aged; D008957:Models, Genetic; D010641:Phenotype; D012307:Risk Factors; D012931:Social Environment; D014429:Twins, Dizygotic / Q000235:genetics / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics / Q000523:psychology