Friday, August 16, 2013

Genetic Link to Maternal Depression Associated With Psychiatric Illness in Children, Study Finds


Variations in the allele of the oxytocin receptor gene (OXTR) may be a cause of long-term psychiatric disorders in children of women who suffer from postpartum and chronic depression, according to a study published July 12 in AJP in Advance. Researchers at the University Bar-Ilan in Israel and the National University of Singapore evaluated 46 chronically depressed mothers who reported depressive symptoms two days after giving birth and compared them with 103 mothers reporting no depression. Six years later, children from each group were assessed for psychiatric disorders, social engagement, and empathy.

Results showed that 61% of children of depressed mothers were diagnosed with Axis I disorders using DSM-IV criteria. Children of nondepressed mothers were four times less likely to develop psychopathologies and were more likely to be socially interactive and empathetic than those who mothers had depression.

The researchers then looked at the association between oxytocin levels and oxytocin-related genetic variations and depression. Previous research has shown that individuals with a single variant of the OXTR rs2254298 polymorphism (the G variant) are at greater risk for autism and major depressive disorder, and those possessing two copies (the GG variant) are more likely to have emotional detachment. However, the presence of the A variant is associated with heightened emotional security. AA homozygous trait carriers have been shown to exhibit social synchrony and physical affection because they have higher levels of oxytocin.

Data showed that depressed mothers and their children had significantly lower oxytocin levels and a greater incidence for the GG trait than families of nondepressed mothers. Among depressed mothers, the presence of the GG allele correlated with a 62% occurrence of child Axis I disorders, while the possession of a single A or AA allele, regardless of depression state, decreased the offsprings’ psychopathologies by at least half.

“What’s amazing is that this study is exquisitely sensitive to epigenetic effects,” Eric Hollander, M.D., director of the Compulsive, Impulsive and Autism Spectrum Disorder Program at Albert Einstein College of Medicine, who reviewed the report for Psychiatric News, said in an interview. “It’s seems that having the resilience [AA] allele, rather than the pathological [GG] allele, is more important, because the presence of A allele rescued children of depressed mothers from psychiatric disorders.”

For more about this study, see the Psychiatric News article "Genetic Link to Maternal Depression Associated With Psychiatric Illness in Children."

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