Positive Marijuana Research Database
Prohibition of cannabis (marijuana) for the last 70 or so years led to many unfounded claims about it’s damaging effects. Claiming that it would “shrink your brain” was one that some of you may have heard. In yet another study, that shrinking brain concept has again been proven to be completely false. Seventy-nine daily users […]
As part of the Philadelphia Neurodevelopmental Cohort, high-resolution T1-weighted MRIs were obtained from 781 youth aged 14–22 years. This sample included 147 cannabis (marijuana) users (109 used 1–2 times per week and 38 used 3 or more times per week) and 634 cannabis non-users. Several structural neuroimaging measures were examined, established procedures for stringent quality […]
For decades misconceptions have persisted about cannabis (marijuana) due to poor studies and the propaganda of prohibition. Good science is eliminating many of those misconceptions. This study set out to determine the association of alcohol use with gray matter volume and white matter integrity; and of cannabis use and gray matter volume and white matter […]
Studying older adults offers an opportunity to explore associations among cannabis use, brain structure, and cognitive function and to observe any potential harm or benefit from the use of cannabis (marijuana). This pilot study used structural MRI to compare brain volume and function between users and non-users of marijuana. On average, the users had 23.5 […]
Magnetic Resonance Imaging (MRI) was used to search for any effects on the hippocampus, which is a region of the brain especially involved in memory as well as motion. A group of 22 older, long-term cannabis (marijuana) users with an average lifetime of 20,100 smoking episodes were compared to 26 comparison subjects with no history […]
During the several recent decades of cannabis (marijuana) prohibition, usage of the plant was often associated with negative brain effects in the propaganda pushed forth by those who profited from making the plant illegal. “Frying your brain” is one phrase that comes to mind. At the extreme end of the spectrum are those who will […]
The hippocampus is a component of the brain associated with long term memory and spatial navigation. There has been ongoing debate regarding the effect of cannabis (marijuana) on hippocampal volume, and whether or not earlier age initiation of use, or higher doses of marijuana have any effect on its size. This study matched 20 heavy […]
This study may very well represent the first neuroimaging investigation of patients using marijuana for medical purposes, and the results are both astounding and exciting! This is distinctly different from past evidence regarding recreational use showing potential cognitive deficits. The difference between medical and recreational use will be described further in a moment. At the […]
It is very likely that anyone who has heard the term “marijuana” has also heard of its supposed negative effects on brain development. One manner of evaluating brain development is the measurement of volume or size of various individual regions. The authors of this study set out to evaluate the reputed impact of cannabis (marijuana) […]