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Twin, sister studies indicate similar estimated heritability of perinatal depression

According to analysis of a twin study and a sibling study, heritability of perinatal depression was estimated at 54% and 44%, respectively, and the heritability of nonperinatal depression was 32%.

“Given the uncertainty about the degree to which perinatal depression and nonperinatal depression are distinct and the limited literature on the genetic basis of depression during the perinatal period, there is a great need for an improved understanding of the genetic basis of perinatal depression and the extent of the genetic overlap between perinatal and nonperinatal depression,” Alexander Viktorin, MSc, of Karolinska Institutet in Stockholm, and colleagues wrote.

To determine significance of genetic and environmental influences on perinatal depression and genetic associations between perinatal and nonperinatal depression, researchers used structural equation modeling to assess data for 3,427 Swedish female twins and depression diagnoses between 580,006 Swedish sisters.

Heritability of perinatal depression was an estimated 54% (95% CI, 35-70) with remaining variance attributed to nonshared environment (46%; 95% CI, 31-65), according to the twin study.

Among sisters, heritability of perinatal depression was an estimated 44% (95% CI, 35-52) and heritability of nonperinatal depression was 32% (95% CI, 24-41).

According to bivariate analysis, 14% of the total variance and 33% of genetic variance in perinatal depression was unique for perinatal depression.

“This study highlights the critical need for clinicians providing obstetrical care to obtain detailed information regarding the patient’s personal and family history of any psychiatric illness that began in a perinatal period. Integration of genetic risk with environmental influences is vital for the appropriate tailoring of individual treatment and discussions of prognosis,” Viktorin and colleagues wrote. “We believe that perinatal depression represents a form of unipolar mood disorder that can be utilized by clinicians in discussions with their patients and could be prioritized for genomic discovery efforts.” – by Amanda Oldt

Disclosure: Viktorin reports no relevant financial disclosures. Please see the full study for a list of all authors’ relevant financial disclosures.