Biological basis of (drug) addiction
Quote:
> Does anybody out there know anything about the biological basis
>of drug {*filter*}ion? I am more curious about substances that very quickly
>cause physical dependency.
Well, from a clinical perspective, there aren't any substances which
have the effect "very quickly". It takes a few weeks of administration
of any of the {*filter*} commonly classified as being "physically {*filter*}ive"
to produce a significant abstinence syndrome upon their withdrawal.
Interestingly enough, it *is* possible to discern the *process* of,
say, opiate dependence in experimental situations in both men and
animals after a single administration of a drug like morphine.
Which is to say that the body begins to adapt immediately, although
this doesn't become important from a clinical or behavi{*filter*}standpoint
until later.
Quote:
>What drastic change can take place in
>the body (brain? organs?) that make it impossible to live without
>the drug?
Sudden withdrawal of sedatives ({*filter*}, barbiturates, benzodiazepines
and related {*filter*}) can produce convulsions which may be life-threatening.
Opiate withdrawal ({*filter*}, morphine, etc.) ranges from mildly to very
uncomfortable, but isn't life-threatening unless the person is severely
debilitated from some other condition. So, your question isn't really
on the mark.
Quote:
>For that matter, how is the process reversed with drug
>treatment programs?
Acute detoxification is usually accomplished by administering the individual
an adequate dose of a drug pharmacologically equivalent to the one they were
dependent on, and then slowly reducing the dose over a period of days or
somewhat longer. The phrase "drug treatment program" usually involves
counseling and therapy along with detox.
The biochemical basis of dependence is not fully understood, even in
particular cases like opiate dependence. What is clear is that neural
systems are complex, with complex feedback loops, and the administration
of certain {*filter*} will cause a cascade of effects down the line. Over time,
the nervous system "adjusts" by modifying the sensitivity of certain
receptors or changing the release of certain neurotransmitters. Suddenly
removing the drug upsets the new equilibrium, and this may be manifested by
a withdrawal syndrome. In the case of opiate withdrawal, one of the
neurochemical effects seems to be an excess of noradrenergic activity;
alpha-2 adrenergic stimulants like clonidine seem to suppress some of the
uncomfortable symptoms of opiate withdrawal by reducing this activity
by stimulating pre-synaptic inhibitory neurons.
--
Steve Dyer
