E-mail sent in by Dr Jim.
Well, sure - nobody said people
with mental problems should smoke pot.
The study was published in the November issue of the British Journal of Psychiatry.
Highly Significant Volume Reduction
In the current study, Dr. Welch and colleagues compared structural changes in the thalamus
and amygdala-hippocampal complex over time in 57 people aged between 16 and 25 years
who were well but who had a strong family history of schizophrenia.
Again, people with a history of mental problems shouldn't smoke pot.
Aren't we debating the 99% who don't have mental problems?
Each person had a full assessment, including a magnetic resonance imaging scan.
Two years later, each person returned for another scan and were also asked about
their use of illicit drugs, including marijuana, as well as their use of alcohol and tobacco
in the period between the scans.
Of the 57 participants, 25 had used marijuana between the 2 assessments.
The researchers found that those participants who had used marijuana showed a reduction
in their thalamic volume that was significant on the left side of the thalamus (F = 4.47; P = .04),
and highly significant on the right (F = 7.66; P = .008). However, no loss of thalamic volume
was noted in those who did not use marijuana during the 2-year period.
I have a question:
What is the effect of a daily bottle of Jack Daniels on the thalamus?
Assuming the effect is negative, should whiskey be illegal in America?
Some of the participants who used marijuana also used other drugs such as ecstasy and amphetamines.
After controlling for the use of these other drugs, the results remained significant.
Potentially Devastating Consequences
"This is the first longitudinal study to show that cannabis use by individuals at increased
risk of schizophrenia is resulting in their brain developing in a different way from the way
it develops if they do not use the drug," Dr. Welch noted.
"These are people who are currently well, not psychotic, and their use of the drug is associated
with volume loss in a critical brain structure. By far the most likely explanation for this is that it is
the cannabis exposure which is causing these abnormalities of brain development," he said.
The thalamus is a very important brain structure that acts as an information processing and relay
station for the brain, he added. "Given this role in interconnecting diverse brain regions, anything
that affects its structure, and consequently, one assumes, its function, would be expected to have
widespread and potentially devastating consequences."
So, if drinking vodka was deemed "harmful to patients with a family history of schizophrenia,"
would these doctors lobby for the prohibition of alcohol?
Blinking lights can cause seizures in people with a family history of epilepsy.
Should we move to ban blinking lights?
Dr. Welch warned that these findings should not be misconstrued to suggest that marijuana use is safe
if one has no such family history. However, "it seems safe to say that if you do have such a background
you should be particularly wary of the drug," he said.
Nobody is debating "safe."
All drugs can kill, even aspirin.
Hell, water and electricity and forks can kill - do we ban everything?
We are debating the relative harm pot does when compared to more dangerous
drugs that are legal and sold in the United States such as liquor and cigarettes.
To use fancy doctor-talk, it's contraindicated.
It's like saying you can board an aircraft with a knife with a foot-long blade,
but we don't allow knives with four inch blades or smaller.
Obviously, the foot-long blade has the potential to do much more damage,
just as booze and cigarettes are much more dangerous than pot.
Jean Bidlack, PhD, Paul Stark Professor of Pharmacology at the University of Rochester School
of Medicine and Dentistry in New York, told Medscape Medical News that the study by Dr. Welch
and colleagues adds something useful to what is already known on the subject.
"This is the first study to show an association between a decrease in the volume of the thalamus
and the use of marijuana in currently unaffected people who are at a high risk of developing
schizophrenia due to family history," Dr. Bidlack said.
But that's not the debate we're having.
"A decrease in the volume of the thalamus has been associated with psychosis and schizophrenia.
The thalamus has a high level of cannabinoid receptors, which bind the active ingredient in marijuana
and may contribute to the decrease in the volume of the thalamus," she explained.
This research begins to explain the link between marijuana use and the development
of schizophrenia in this high-risk group, she said.
Dr. Welch and Dr. Bidlack have disclosed no relevant financial relationships.
This is like debating whether school bus drivers should be allowed to drink on the job.
Nobody is suggesting that - so why would we waste time with that debate?
We can't allow those with mental problems to dictate the availability and legality of recreational drugs.