According to a new longitudinal study published in the journal Drug and Alcohol Dependence, there is some initial evidence that preconception cannabis use is associated with an increased risk of postpartum depression.
The research team out of Australia wanted to see whether marijuana use was a risk factor for postpartum depression, given that almost one in five new months may experience the symptoms.
“The legalization of cannabis use in many regions worldwide witnessed increased use and decreased perception of associated harms. Recent studies from the United States and Canada even reported significant increases in cannabis use during the preconception period in states that had legalized recreational cannabis,” explained Sifan Cao, a PhD candidate at The University of Queensland and the corresponding author of the study.
“The Australian Capital Territory legalized personal cannabis use on January 31, 2020, so it would not be surprising to see an increase in preconception cannabis use here in the future. About 21% of young women in this study had used cannabis, despite it being illegal in Australia at the time of the surveys.”
“Previous evidence has linked cannabis use with an increased risk of depression,” Cao added.
“Therefore, preconception cannabis use may be associated with a higher risk for postpartum depression; however, no previous studies have examined this. Given that postpartum depression affects about 1 in 5 women in their first year after delivery and has harmful impacts on the woman, her child, and the family, investigation of preconception cannabis use and its associations with postpartum depression will help inform possible prevention strategies.”
The team had examined data from a cohort of 17,011 young women who were recruited for the Australian Longitudinal Study on Women’s Health in 2012 and 2013. As part of the annual survey, participants were asked if they had used cannabis in the past year.
“In Australia, women in their 20s are the most likely to use cannabis across all age groups; they also make up the most significant proportion (36.9%) of mothers,” Cao stated. “Therefore, it is of greatest priority to determine whether preconception cannabis use is associated with a higher risk of postpartum depression in this age group.”
The study revealed that approximately 22% of the women who gave birth during the course of the study reported that they had used cannabis 3 to 15 months before their pregnancy.
“Cannabis use before pregnancy was associated with an increased risk of postpartum depression, and the level of increased risk was dependent on the extent of cannabis exposure. Chronic use before pregnancy was associated with a higher risk of subsequent postpartum depression. The closer the cannabis use was relative to pregnancy, the higher the risk for postpartum depression,” said Cao.
“Our study was the first of its kind that investigated the links between preconception cannabis use and postpartum depression,” Cao also added. “The major limitation of our study is that we had no details about the dose, frequency, or duration of preconception cannabis use. That means even one-off experimental use, if reported, would classify as having used cannabis. Also, the preconception period ranged from 3 to 15 months before pregnancy. Therefore, future studies considering the dose, frequency, and duration of cannabis use are needed to confirm our findings.”
“Current clinical recommendations encourage pregnant women or those contemplating pregnancy to discontinue cannabis use, mainly because of the adverse health consequences of continued use during pregnancy,” Cao noted. “Our findings extend the harms of cannabis use to preconception use and provide evidence for the benefits of quitting cannabis use at least 15 months before pregnancy.”
“If other studies confirmed our results, we would expect clinical recommendations to encourage cannabis cessation in the preconception period. By then, health providers could consider educating women who use cannabis during preconception consultancies on the harmful effects of cannabis use and the health benefits of quitting.”