JAMA Netw Open. 2020;3(8):e2013802. doi:10.1001/jamanetworkopen.2020.13802
Findings In this repeated cross-sectaional study of 16 216 adults, those with depression increased their rates of cannabis use significantly faster than those without depression. In 2005 to 2006, individuals with depression had 46% higher odds of any cannabis use and 37% higher odds of near-daily cannabis use, while in 2015 to 2016, individuals with depression had 130% higher odds of any cannabis use and 216% higher odds of daily cannabis use.
Meaning In this study, an increasing number of adults with depression used cannabis during the study period.
Importance Despite studies showing that repeated cannabis use may worsen depressive symptoms, the popular media increasingly presents cannabis as beneficial to mental health, and many members of the public view cannabis as beneficial for depression. Therefore, cannabis use among individuals with depression may be becoming more prevalent.
Conclusions and Relevance The findings of this study indicate that individuals with depression are at increasing risk of cannabis use, with a particularly strong increase in daily or near-daily cannabis use. Clinicians should be aware of these trends and the evidence that cannabis does not treat depression effectively when discussing cannabis use with patients.
The current article from the American Heart Association critically reviews the use of medicinal and recreational marijuana from a clinical, policy, and public health standpoint. While medical marijuana may play a therapeutic role in certain disease…data to date do not support its use as a therapy for cardiovascular disease. In fact, cannabis has been associated with adverse cardiovascular events, including myocardial infarction (especially in younger patients), arrhythmias, strokes, heart failure, and cardiovascular mortality. While it has been postulated that some components of marijuana may be cardioprotective (cannabidiol, or CBD), the THC (delta-9-tetrahydrocannabinol) component stimulates the sympathetic nervous system and is associated with endothelial dysfunction and oxidative stress... There is an urgent need for well-designed prospective studies to examine the effect of both the acute and long-term effects of marijuana on the cardiovascular system, especially since current forms of marijuana have higher doses of THC than in the past.
The authors of this American Heart Association scientific statement review the use of medicinal and recreational cannabis both for medicinal and recreational purposes, which has expanded over the last 2 decades. Cannabis has little benefit for the cardiovascular system but many of the adverse effects include cardiovascular disease. The authors review the safety and efficacy of cannabis for a variety of indications as well as for recreation while also considering the policy and public health perspective.
Further research is urgently needed to provide high-quality evidence regarding the risks and benefits of cannabis to inform both members of the public and policy.
— "Another piece of the puzzle" of how marijuana use affects childhood outcomes
Children exposed to marijuana in utero had a moderately elevated risk of developing autism spectrum disorder, according to a Canada-based retrospective study.
Mothers who used cannabis while pregnant had a 50% higher likelihood of having a child with autism (adjusted hazard ratio 1.51, 95% CI 1.17–1.96), reported Daniel Corsi, PhD, of Ottawa Hospital in Ontario, and colleagues.
Hints of increased risk of intellectual and learning disabilities and attention deficit hyperactivity disorder (ADHD) were also seen, according to their paper in Nature Medicine.
Nevertheless, said Corsi in an email to MedPage Today ,"[o]ur clinical recommendation based on these findings is for women who are pregnant or thinking of becoming pregnant to avoid the use of cannabis products."
Torri Metz, MD, a maternal-fetal medicine specialist at the University of Utah, commented that this study adds to previous concerns about prenatal marijuana exposure's potential effects on offspring.
"It is another piece of the puzzle," Metz, who was not involved in this research, told MedPage Today. "It makes us worry about cannabis exposure in utero and whether it is influencing fetal neurodevelopment." Metz also underscored the importance of interpreting these findings with caution, as this large population-based study was limited in its classification of substance use.
Lauren Jansson, MD, the director of pediatrics at the center for addiction and pregnancy at Johns Hopkins Bayview Medical Center, said that she hopes this study will further encourage clinicians to counsel patients to avoid marijuana use, not only during pregnancy, but while breastfeeding as well.
"We know that medical providers often tend to discount cannabis use as unimportant, and we know that counseling -- even during pregnancy -- is inconsistent," Jansson, who was not involved in this study, said in an interview. "With studies like this, it's more data that will support recommendations for women to at least stop using in pregnancy."
Using the Ontario Better Outcomes Registry & Network (BORN), researchers examined the association between cannabis exposure and risk of neurodevelopmental disabilities. They analyzed more than 500,000 births that occurred between 2007 and 2012, and followed children for up to 10 years. In this group were 3,148 mothers who used cannabis (0.6%).
The researchers also found trends toward increased incidence of intellectual and learning disabilities (HR 1.23, 95% CI 0.97–1.55), as well as ADHD (HR 1.11, 95% CI 0.99–1.25) in the matched cohort among children whose mothers used marijuana. These remained nonsignificant after further adjustment.
"We certainly need more information about marijuana use and downstream effects for offspring who are exposed in utero," Metz said. "It's exciting to see that people are evaluating this."
Primary Source: Nature Medicine - Source Reference: Corsi D, et al "Maternal cannabis use in pregnancy and child neurodevelopmental outcomes" Nature Medicine 2020; DOI: 10.1038/s41591-020-1002-5.
FDA strongly advises against the use of cannabidiol (CBD), tetrahydrocannabinol (THC), and marijuana in any form during pregnancy or while breastfeeding.
What do we know about the effects of marijuana use during pregnancy and while breastfeeding?
There are many potential negative health effects from using marijuana and other products containing THC during pregnancy and while breastfeeding. In fact, the U.S. Surgeon General recently advised consumers that marijuana use during pregnancy may affect fetal brain development, because THC can enter the fetal brain from the mother’s bloodstream. The Surgeon General also advised that marijuana may increase the risk of a newborn with low birth weight. Research also suggests increased risk for premature birth and potentially stillbirth1.
While breastfeeding, it is important to know that breastmilk can contain THC for up to six days after use. This THC may affect a newborn’s brain development and result in hyperactivity, poor cognitive function, and other long-term consequences.
Additionally, marijuana smoke contains many of the same harmful components as tobacco smoke. Neither marijuana nor tobacco products should be smoked around a baby or children.
What do we know about the effects of CBD use during pregnancy and while breastfeeding?
There is no comprehensive research studying the effects of CBD on the developing fetus, pregnant mother, or breastfed baby. FDA is continuing to collect and study the data on the possible harmful effects of CBD during pregnancy and while breastfeeding. However, based on what we do know, there is significant cause for concern.
High doses of CBD in pregnant test animals have caused problems with the reproductive system of developing male fetuses2 . In addition, based on what we already know about CBD, we expect that some amount of CBD will be transferred to babies through breast milk.
We also know that there is a potential for CBD products to be contaminated with substances that may pose a risk to the fetus or breastfed baby, including THC. We have also heard reports of CBD potentially containing other contaminants (e.g., pesticides, heavy metals, bacteria, and fungus); we are investigating this.
Moreover, CBD has known risks for people in general. Based on clinical studies in humans, risks can include the following:
FDA is studying the effects of CBD use from different angles, such as: (1) the use of CBD-containing products, like food, cosmetics, or supplements, over a person’s entire life; and (2) the effects of using these various products in combination. There are many unanswered questions about the science, safety, and quality of products containing CBD.
We especially want to learn more about the effects of CBD during pregnancy and while breastfeeding, including, for example, whether and to what extent the presence of CBD in human milk harms the breastfed baby or the mother’s milk production.
Has FDA approved any CBD products and are there any benefits?
FDA has not approved any CBD products except for one prescription drug to treat rare, severe forms of seizure disorders in children. It is still unclear whether CBD has any other benefits.
Other than the one approved prescription drug, CBD products have not been evaluated or approved by FDA for use as drug products. This means that we do not know:
The clinical studies that supported the approval of the one available CBD drug product identified risks related to the use of CBD, including liver toxicity (damage), extreme sleepiness, and harmful interactions with other drugs.