Seven out of 10 college students say it is somewhat or very easy to obtain controlled stimulants without a prescription, according to a new survey conducted on eight US campuses.

Nicotine use over time increases the speed that codeine is converted into morphine within the brain, by increasing the amount of a specific enzyme, according to new research in rat models. It appears smokers’ brains are being primed for a bigger buzz from this common pain killer — which could put them at a higher risk for addiction, and possibly even overdose. These findings are part a new way of seeing the brain’s role when it comes to drugs and toxins.

A few minutes of counseling in a primary care setting could be an effective tool in steering people away from risky drug use, and possibly full-fledged addiction, a new report suggests. The researchers found that this sort of intervention helped patients reduce their risky drug use by one-third.

Excessive alcohol use continues to be a drain on the American economy, according to a study. Excessive drinking cost the U.S. $249 billion in 2010, or $2.05 per drink, a significant increase from $223.5 billion, or $1.90 per drink, in 2006. Most of these costs were due to reduced workplace productivity, crime, and the cost of treating people for health problems caused by excessive drinking.