Pubdate: Tue, 12 Jan 2016
Source: Observer, The (CN ON)
Copyright: 2016, Sarnia Observer
Contact: http://www.theobserver.ca/letters
Website: http://www.theobserver.ca
Details: http://www.mapinc.org/media/1676
Author: Jonathan Sher
Page: A3

KEEP POT AWAY FROM TEENS, RESEARCHERS URGE

Western researchers found marijuana poses serious consequences for
teens, but not adults

Turns out getting stoned on marijuana carries much more dire
consequences for teenagers than for adults -- at least if you're a rat
and part of a new study released Monday by researchers in London.

Researchers at Western University's Schulich School of Medicine &
Dentistry have published a study that shows that the psychoactive
component of marijuana caused long-term harm on the adolescent brains
of rats, producing changes similar to what is found in
schizophrenia.

"Adolescence is a critical period of brain development and the
adolescent brain is particularly vulnerable," said Steven Laviolette,
a professor in the departments of anatomy and cell biology, and
psychiatry. "Health policy makers need to ensure that marijuana,
especially marijuana strains with high THC levels, stays out of the
hands of teenagers. In contrast, our findings suggest that adult use
of marijuana does not pose substantial risk."

After adolescent rodents were exposed to delta-9-tetrahydrocannabinol
(THC) - the psychoactive component in marijuana - researchers found
substantial and persistent behavioural, neuronal and molecular changes
that are identical to neuropsychiatric conditions, such as
schizophrenia.

Adolescent rodents with THC exposure were socially withdrawn, and had
increased anxiety, cognitive disorganization and abnormal levels of
dopamine - all factors present in clinical populations of
schizophrenia. These changes continued into early adulthood, well past
the initial exposure.

Adult rodents showed no harmful long-term effects, though both
adolescents and adults exposed to THC experienced deficits in social
cognition and memory.

With the common use of marijuana by teenagers and the federal
government's move toward legalizing marijuana, researchers say that
pot should be kept out of the hands of teens.

"Our research improves our knowledge of how adolescent exposure to THC
may lead to the onset of schizophrenia in adulthood," lead author
Justine Renard said. "With the current rise in adolescent cannabis use
and the increasing THC content in newer cannabis strains, it is
critically important to highlight the risk factors associated with
exposure to marijuana, particularly during adolescence."

Researchers identified and performed tests in areas of behaviour that
are commonly observed in schizophrenia and other neuropsychiatric
disorders, such as social interaction, motivation and cognition,
exploratory behaviours, levels of anxiety, cognitive disorganization
(the inability to filter out unnecessary information), and various
neuronal and molecular changes.
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MAP posted-by: Matt