Heritability of Perinatal Depression and Genetic Overlap With Nonperinatal Depression.
OBJECTIVE
The authors investigated the relative importance of genetic and environmental influences on perinatal depression, and the genetic overlap between perinatal depression and nonperinatal depression.


METHODS
Analyses were conducted using structural equation modeling for 1) the lifetime version of the Edinburgh Postnatal Depression Scale in 3,427 Swedish female twins and 2) clinical diagnoses of depression separated into perinatal depression and nonperinatal depression in a Swedish population-based cohort of 580,006 sisters.


RESULTS
In the twin study, the heritability of perinatal depression was estimated at 54% (95% CI=35%-70%), with the remaining variance attributable to nonshared environment (46%; 95% CI=31%-65%). In the sibling design, the heritability of perinatal depression was estimated at 44% (95% CI=35%-52%) and the heritability of nonperinatal depression at 32% (95% CI=24%-41%). Bivariate analysis showed that 14% of the total variance (or 33% of the genetic variance) in perinatal depression was unique for perinatal depression.


CONCLUSIONS
The heritability of perinatal depression was estimated at 54% and 44%, respectively, in separate samples, and the heritability of nonperinatal depression at 32%. One-third of the genetic contribution was unique to perinatal depression and not shared with nonperinatal depression, suggesting only partially overlapping genetic etiologies for perinatal depression and nonperinatal depression. The authors suggest that perinatal depression constitutes a subset of depression that could be prioritized for genomic discovery efforts. The study findings have direct translational impact that can assist clinicians in the counseling of their patients regarding risk and prognosis of perinatal depression.
From the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm; the Departments of Psychiatry and Genetics, University of North Carolina School of Medicine, Chapel Hill; and the Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Alexander
A
Viktorin
From the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm; the Departments of Psychiatry and Genetics, University of North Carolina School of Medicine, Chapel Hill; and the Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Samantha
S
Meltzer-Brody
From the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm; the Departments of Psychiatry and Genetics, University of North Carolina School of Medicine, Chapel Hill; and the Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Ralf
R
Kuja-Halkola
From the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm; the Departments of Psychiatry and Genetics, University of North Carolina School of Medicine, Chapel Hill; and the Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Patrick F
PF
Sullivan
From the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm; the Departments of Psychiatry and Genetics, University of North Carolina School of Medicine, Chapel Hill; and the Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Mikael
M
Landén
From the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm; the Departments of Psychiatry and Genetics, University of North Carolina School of Medicine, Chapel Hill; and the Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Paul
P
Lichtenstein
From the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm; the Departments of Psychiatry and Genetics, University of North Carolina School of Medicine, Chapel Hill; and the Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Patrik K E
PK
Magnusson
D000328:Adult; D019052:Depression, Postpartum / Q000235:genetics* / Q000523:psychology; D003866:Depressive Disorder / Q000235:genetics* / Q000523:psychology; D005260:Female; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000235:genetics* / Q000523:psychology; D035781:Siblings; D013548:Sweden; D014429:Twins, Dizygotic / Q000235:genetics* / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics* / Q000523:psychology