Stress hormones during pregnancy can set girls up for nicotine addiction
Women whose mothers had high levels of stress hormones during pregnancy are more likely to become addicted to nicotine, reports a new study in the journal Biological Psychiatry.
This research is the first to provide evidence that exposure to stress hormones in utero can predict nicotine dependence later in life, but only for girls.
A 'double hit'
Lead study author Laura Stroud, Ph.D., from the Centers for Behavioral and Preventive Medicine at The Miriam Hospital, said that maternal smoking during pregnancy has been shown to be a risk factor for nicotine dependence, but researchers were unclear about what mechanisms were responsible for this – until now.
"Our study suggests that maternal smoking and high stress hormones – often linked to high stress and adverse social conditions – represent a 'double-hit' in terms of increasing an offspring's risk for nicotine addiction as an adult," Stroud said in a statement.
The research team studied both maternal smoking and cortisol levels to determine how these factors affected nicotine dependence later in life. Increased exposure to glucocorticoids (stress hormones), they found, was linked to a 13 percent increased risk of nicotine dependence in girls over a 40-year follow-up period.
Stroud and her team aren't sure why daughters were affected more than sons, but it may have to do with how cortisol affects developing organs.
"Possible mechanisms include sex differences in stress hormone regulation in the placenta and adaptation to prenatal environmental exposures," Stroud said. "Also, cortisol and nicotine may affect developing male and female brains differently."
Since mothers who smoke are usually more stressed – and living in adverse conditions – Stroud said, the findings represent a public health concern that should involve improving social conditions for low-income pregnant mothers.
"If daughters of smoking mothers are more likely to grow up nicotine dependent, the result is dangerous cycle of intergenerational transmission of nicotine addiction," she added.
Source: Science Daily