Author Interviews, Cannabis, Cognitive Issues, OBGYNE / 05.11.2018
Prenatal Heavy Cannabis Exposure May Diminish Cognitive Functioning Into Adulthood
MedicalResearch.com Interview with:
[caption id="attachment_45711" align="alignleft" width="133"]
Dr. McLaughlin[/caption]
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.
Dr. McLaughlin[/caption]
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.
Sean C. Rose, MD
Pediatric sports neurologist and co-director
Complex Concussion Clinic
Nationwide Children’s Hospital
Assistant professor of Pediatrics
The Ohio State University
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: The link between sub-concussive head impacts and declines in neurocognitive function has been reported by some studies, yet refuted by others. There is very little evidence that has been collected in children as they are sustaining these head impacts.
We initiated a multi-year study of youth football players to provide a more in-depth look at the question. We measured head impacts using helmet sensors during the 2016 football season. 112 players age 9-18 completed a battery of neurocognitive tests before and after the football season.
We found that neither the total burden of head impacts nor the intensity of individual impacts were associated with changes in testing performance from pre to post-season.
Dr. Nicole Karcher, PhD
Post-doctoral scholar with the NIMH Training in Clinical Sciences fellowship
Department of Psychiatry
Washington University School of Medicine
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: For over fifteen years, researchers have debated the role that cannabis use plays in the development of both psychotic disorders as well as subthreshold psychotic symptoms, such as psychotic-like experiences (PLEs). There is still a lack of consensus regarding the nature of the association between cannabis use and psychosis risk, with some research finding evidence for genetic overlap, while other research finds evidence for potentially causal pathways.
The current study examined data from twins and siblings from two different samples, the U.S.-based Human Connectome Project and the Australian Twin Registry, with a total of 4,674 participants. Overall, psychotic-like experiences were associated with three separate cannabis use variables [frequent (≥100 times) use, a Cannabis Use Disorder diagnosis, and current cannabis use]. Furthermore, the current research found evidence for both shared genetic and individual-specific contributions to the association between PLEs and these three cannabis use variables. More specifically, while the association between cannabis use and psychotic-like experiences was largely attributable to shared genetic factors, cannabis users were more likely to endorse PLEs in comparison to the relative who used cannabis less.









