Smoking ‘leaves you vulnerable to effects of cocaine’

It could help explain why so many drug-using teenagers tend to start with cigarettes and alcohol before moving on to more illegal substances,the researchers said.

The idea that taking legal drugs could make a person more vulnerable to illegal drugs was first suggested in 1975. This is the first study to find a biological mechanism which could prove such a causal link does exist,the Daily Mail reported.

In the latest study on mice,researchers at the Columbia University in New York found the rodents exposed to nicotine through their drinking water for one week showed an increased response to cocaine.

This priming effect depend on the previously unrecognised impact that nicotine made on gene expression. It was found to reprogramme specific genes linked to addiction making the brain more responsive to harder drugs,the researchers said.

The results parallelled findings in humans after the team re-examined statistics from the 2003 National Epidemiological Study of Alcohol Related Consequences. It was found that the rate of cocaine dependence was higher among cocaine users who smoked earlier than those who tried cocaine prior to smoking.

The new findings suggest quitting smoking would not only prevent its damaging effects but could also decrease the risk of progression and addiction to cocaine and other drugs. “Now that we have a mouse model of the actions of nicotine as a gateway drug this will allow us to explore the molecular mechanisms by which alcohol and marijuana might act as gateway drugs,” said study author Dr Eric Kandel.

“In particular,we would be interested in knowing if there is a single,common mechanism for all gateway drugs or if each drug utilises a distinct mechanism.”