February 11, 2010

Scientists Discover Cause Of Prescription Drug Addiction

Scientists announced Wednesday they have solved the mystery behind why people become addicted to a class of prescription drugs that includes some anti-depressants, muscle relaxants and sleeping pills, reported AFP.

Reported in the British science journal Nature, researchers hope the findings will pave the way for the development of new treatments that can alleviate symptoms without resulting in addiction.

Scientists know that drugs like opium, heroin and cannabinoids are addictive because they trigger a neural circuit that causes a surge in levels of a brain chemical called dopamine. The molecular path the drugs take to unleash this chemical is well understood.

Benzodiazepines such as Valium, Xanax, Librium, Ambien and other well-known drugs also stimulate the dopamine system, but scientists are just now discovering how they accomplish this.

The team of researchers led by Christian Luscher at the University of Geneva claim to have figured how such drugs work after a series of experiments performed on mice.

They found that Benzodiazepines turn on an intermediary neurotransmitter called gamma-aminobutyric acid, or GABA, and increase dopamine levels, leading to the strong craving associated with addiction.

The uncovered pathway does not have an impact on the therapeutic effects of benzodiazepines.

Therefore, it should be possible to make new drugs that offer the same benefits without getting the user hooked, said the researchers.

Arthur Riegel and Peter Kalivas of the Medical University of South Carolina in Charleston referred to the work as "a landmark for the field."

"These authors are the first to identify a molecular mechanism contributing to benzodiazepine abuse," they wrote in a commentary in Nature.


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