Jane Kelley wrote in a message to Alex Vasauskas:
 JK>  Physiological research, including what I have presented
AV>to you here previously and that you have chosen to ignore, has
 JK> I've got too many books that are full of physiological research. 
I would be surprised if you have any reliable physiological research
conclusively demonstrating that marijuana has physiological effects
associated with addiction.
Some day there may be a reliable study conclusively demonstrating that
marijuana induces chemical changes in the human brain that are commonly
associated with proven drugs of dependence.  For example, if a study
demonstrated that marijuana stimulates the release of the neurochemical
dopamine in the so-called "reward pathways" of the brain and that
subjects suffered effects of physical withdrawal upon, for example, the
administration of a blocking agent directly into the brain, I would
agree that marijuana may be addictive rather than just habituative to
*some* people.
I would limit this to *some people* because decades of epidemiological
human research have failed to demonstrate that marijuana has the kind of
serious dependence liability of heroin, alcohol, or tobacco.  In fact,
the government study that I recently provided you a copy of here
determined that marijuana did not even come up to the level of
caffeinated coffee, let alone alcohol or cigarettes, in terms of
behavioral effects considered to demonstrate addiction.
Many substances have some dependence liability, including legal ones
like chocolate, sugar, and caffeine, and illegal ones, such as heroin.
The concern regarding addiction is *not* whether or not marijuana or
any other substance has any dependence liability, but its *relative
dependence liability* compared to other things.  The most telling
evidence available in this regard is that while animal studies
demonstrate that animals will self-administer opiates, they will not
under any circumstances self-administer THC, the major active
ingredient in marijuana.
So, please start putting things in proportion.  In terms of the
overall population, marijuana is either not addictive or its
addiction potential is insignificant.  If it is addictive to
some, they are a very small part of the population.  *This* is
the kind of information that can help people to make intelligent
decisions and to weigh the risks and benefits regarding the use
of this, among other, valuable herbs for medicinal and other
purposes.
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