Read your research carefully! In a brand new study to be published in 2019, researchers once again based their research assumptions on reefer madness myths. They wanted to investigate if "cannabis consumption may affect cognitive performance" in cancer patients because "the use of medical cannabis has increased significantly during the recent years".
They found only cognitive ("executive functioning") improvements NOT deficits in the group of patients who use cannabis. Although they claimed cannabis did not affect cognition, they mean negatively of course, because that's the assumption. In reality, cannabis treats many types of brain damage, like chemo fog or chemo brain.
RESULTS: Improvement in executive functioning was demonstrated in the [cannabis] group. In aspects of symptoms, improvement in fatigue, appetite and sleep disorder was demonstrated after cannabis consumption. Patients consuming cannabis did not differ from the control group in cognitive functioning over 3 months of use. No significant cognitive decline was observed in either group over time.
CONCLUSION: These preliminary findings suggest that the short-term use of cannabis during chemotherapy treatment improved disease-related symptoms and did not affect cognitive skills in patients with cancer.
It's strange how things that are scientifically proven to cause brain damage (chemo, concussions, alcohol, etc) are rarely discussed. Meanwhile, people obsessively grasp at straws trying to find the research or make the claim that cannabis might cause "changes" in the brain....changes which they hope the reader will take to mean brain damage.
It's ironic that researchers would try to make this claim with cannabis of all things - a substance scientifically proven to treat many types of brain damage and disease including chemo brain fog. People have the right to know that cannabis can help protect them against chemo's toxic short-term and long-term side effects.
Bar-Sela G et al (Jan 2019). "Cannabis-related cognitive impairment: a prospective evaluation of possible influences on patients with cancer during chemotherapy treatment as a pilot study". Anticancer Drugs. Vol. 30(1), Pp. 91-97. doi: 10.1097/CAD.0000000000000685. https://www.ncbi.nlm.nih.gov/pubmed/30540595