“Cannabis sativa” by Manuel is licensed under CC BY 2.0

Prenatal Heavy Cannabis Exposure May Diminish Cognitive Functioning Into Adulthood

MedicalResearch.com Interview with:

Ryan J. McLaughlin, PhD Assistant Professor Department of Integrative Physiology & Neuroscience College of Veterinary Medicine Washington State University Pullman, WA 99164-7620

Dr. McLaughlin

Ryan J. McLaughlin, PhD
Assistant Professor
Department of Integrative Physiology & Neuroscience
College of Veterinary Medicine
Washington State University
Pullman, WA 99164-7620

MedicalResearch.com: What is the background for this study? What are the main findings? 

Response: The use of cannabis during pregnancy is a growing health concern, yet the long-term cognitive ramifications for developing offspring remain largely unknown. Human studies exploring the long-term effects of maternal cannabis use have been sparse for several reasons, including the length and cost of such studies, as well as the fact that experimentally assigning mothers to smoke cannabis during pregnancy is obviously ethically impractical. Animal models of maternal cannabis use have been advantageous in this respect, but they have been limited by the drugs used (synthetic cannabinoids vs. THC vs. cannabis plant) and the way that they are administered. In our study, we used a more translationally relevant animal model of maternal cannabis use that exposes pregnant rat dams to whole plant cannabis extracts using the intra-pulmonary route of administration that is most common to human users. Our preliminary data indicate that twice-daily exposure to a high-dose cannabis extract during pregnancy may produce deficits in cognitive flexibility in adult rat offspring. Importantly, these rats did not experience general learning deficits, as they performed comparably to non-exposed offspring when required to follow a cue in their environment that dictate reinforcer delivery. Instead, deficits were observed only when rats were required to disregard this previous cue-based strategy and adopt a new egocentric spatial strategy in order to continue receiving the sugar reinforcers.

MedicalResearch.com: What should readers take away from your report?

Response: Although these data are still preliminary, they indicate that prenatal exposure to high doses of cannabis may cause subtle, but meaningful changes in brain development that can negatively impact cognitive functioning into adulthood. With recreational cannabis legalization spreading rapidly throughout North America, there is valid concern that mainstream acceptance of cannabis will be met with reductions in perceived harm of cannabis use during sensitive developmental periods such as pregnancy. Although these data were generated using a rodent model, rather than with human cannabis-exposed offspring, I think that they underscore the importance of being informed of the possible risks associated with the use of cannabis during pregnancy. Hopefully this work will encourage other scientists to dedicate more resources to understanding how cannabis affects the developing brain.   

MedicalResearch.com: What recommendations do you have for future research as a result of this work? 

Response: We urgently need more research exploring putative effects of developmental cannabis exposure, both in humans and preclinical animal models. In regard to the latter, it will be important to consider the use of models that more closely approximate human cannabis use patterns. This will hopefully provide a more translationally-relevant understanding of the effects of prenatal cannabis exposure, which we can then use to interrogate the specific changes in the brain that may be contributing to these impairments in adulthood. 

Disclosures: This project was supported financially by funds provided by the Alcohol and Drug Abuse Research Program at Washington State University, which are derived from excised tax dollars generated from the sale of cannabis products in Washington State. The funders had no role in the study design, data analysis, data interpretation or writing of the abstract. We do not have any competing financial interests to declare.

Citation: Abstract presented at Neuroscience 2018 

Maternal cannabis vapor exposure dose-dependently impairs behavioral flexibility in adult offspring


Integrative Physiol. and Neurosci., Washington State Univ., Pullman, WA
November 4, 2018 Neuroscience 2018

 [wysija_form id=”3″]


The information on MedicalResearch.com is provided for educational purposes only, and is in no way intended to diagnose, cure, or treat any medical or other condition. Always seek the advice of your physician or other qualified health and ask your doctor any questions you may have regarding a medical condition. In addition to all other limitations and disclaimers in this agreement, service provider and its third party providers disclaim any liability or loss in connection with the content provided on this website.


Last Updated on November 5, 2018 by Marie Benz MD FAAD