Kids' asthma linked to mothers' depression

2019-03-02 05:13:03

By Gaia Vince Mothers who suffer from major depression or anxiety disorders are more likely to have children with asthma and other allergy-based conditions, according to a US study. The association was only found for biological children, supporting a “shared genetic liability” theory. Ramin Mojtabai, a psychiatrist from Columbia University in New York, US, assessed the relationship between parental psychopathology and childhood allergy in more than 9000 parent-child pairs from the 1999 US National Health Interview Survey. Most of the parents were biologically related to their children, but 554 of the pairs were non-biological. The survey found that 6% of the parents had major depression, 3% had panic attacks and 3% had generalised anxiety disorder. In total, 31% of the children had allergic disorders including hay fever, eczema, wheezing, asthma and food allergies. Mojtabai’s analysis revealed that mothers who had major depression were 67% more likely to have biological children with allergic disorders, and the increased risk was 46% for mothers who had panic attacks. His study showed no statistically significant link between the psychopathology of parents and allergy in their non-biological children, or between fathers and their biological children. “The fact that adoptive parents with depression didn’t show a higher level of asthma in their children provides good evidence for the possibility of common genes for depression and panic disorder on the one hand, and allergic disorders on the other hand,” Mojtabai told New Scientist. He points out that previous studies had shown an increased risk of depression in children of parents with allergic disorders. Mojtabai says it is unclear why the children of mothers with depression had a higher risk of allergic disorders, but he speculates that it might be related to mitochondria – which are inherited through the maternal line – as mutations in mitochondrial DNA have been reported in both atopic and other skin disorders and in bipolar mood disorder. “Or it could be to do with genetic imprinting – how some genes are expressed when received from one gender, but not the other,” he says. “Other studies have shown a shared genetic risk for allergy and mood disorders in twins, and that people with depression are themselves more likely to suffer from asthma, although we didn’t find any strong evidence for that,” Mojtabai adds. As expected, the study also showed a clear association between parents of either gender with allergies in both biological and non-biological offspring, in common with other studies. “Manifestly, anxiety and asthma reinforce each other, but what this study suggests is that they may also share a common cause,” says Martin Dockrell from Asthma UK. But he adds: “The correlation does not imply causation. It would be wrong to say simply that a parent’s anxiety causes a child’s asthma in the same way that it would be wrong to say simply that a parent’s asthma causes a child’s anxiety. Journal reference: Psychosomatic Medicine (vol 67,