Chronic cannabis use by mothers heightens risk of their young adult offspring using marijuana and tobacco: study

Women were interviewed 10 times over the course of study, while offspring were surveyed at age 22 to measure any drug dependence.

A new U.S. study suggests that women who regularly use cannabis during and after pregnancy may increase the likelihood that their adult offspring smoke cannabis and tobacco.

Chronic maternal use is a concern, authors of the latest study suggest, since the findings show this may predict adult cannabis use and cannabis use disorder (CUD) in their adult offspring.

Per information from Alberta’s health department, CUD occurs when people have become dependent on cannabis. Among others, they may experience extreme changes in mood, trouble concentrating and memory problems.

To find out if maternal weed use affected offspring substance use at age 22, they reviewed information from a year pre-pregnancy to 16 years postpartum.

Recruited from a prenatal clinic between 1982 and 1984, the women were surveyed by trained interviewers twice during pregnancy, at delivery, eight and 18 months following birth and at three, six, 10, 14 and 16 years postpartum. Offspring were measured for substance use and dependence at age 22.

Investigators identified some distinct patterns of maternal cannabis use, including that the offspring of chronic weed users were more likely to use cannabis and develop CUD than the offspring of mothers who did not partake.

But the influence of maternal chronic cannabis use extended beyond weed. The offspring of chronic cannabis users were more likely to be nicotine dependent by age 22 than the children of mothers who did not use cannabis and mothers who were “decreasingly likely to use over time.”

Separate study showed earlier weed use by offspring of ever-use mothers

Although the current study does not note when use and dependence among offspring began, research released in 2018 explored whether or not cannabis use among mothers is associated with earlier cannabis initiation by their children.

Researchers found that the median age of cannabis initiation for children of maternal ever-users was 16 compared to 18 for children of maternal never-users. “Children of one-year and multiple-year users were at increased risk of cannabis initiation between ages six and 16 years,” the authors reported.

Given that maternal cannabis use may be a risk factor for early initiation among their offspring, they recommended “preventive interventions should consider strategies to delay initiation among children of cannabis users.”

That said, another study published in 2018 delved into what investigators called intergenerational transmission of cannabis use. “Results showed that parental CUD was associated with adolescent cannabis use, but parental cannabis use without CUD was not.”