Researchers at Washington State University are developing a breath test for THC, the psychoactive ingredient in marijuana. The test could be used to determine if a person is driving under the influence of marijuana, according to The Seattle Times.

Drug-impaired driving has become an increasing concern since recreational marijuana use became legal in Washington in 2012. The Washington State Toxicology Laboratory reported 25 percent of tested blood samples taken from suspected impaired drivers tested positive for active THC in 2013, compared with 18.6 percent in 2012.

Currently there is no portable tool that allows law enforcement officers to test drivers for marijuana impairment using a breath sample, the article notes. Officers now use blood tests to determine how much THC is present in a driver's blood. Test results are not immediately available.

One-fifth of parents with children under age 18 have blacked out after drinking too much at a party, according to a new survey. One-third of adults who drink at parties admit to driving after consuming too much alcohol, according to the survey commissioned by Caron Treatment Centers.

The survey also found one-third of adults are comfortable with an 18-20 year old drinking at a family holiday party, as long as they have only one glass and are not driving.

The online survey, conducted by Harris Poll, revealed 59 percent of adults age 21 and older who attend holiday parties and drink too much alcohol have engaged in potentially serious and dangerous behavior.

The survey found the majority of those who attend parties have witnessed someone who was "under the influence" at a party arguing with others, using excessive profanity, flirting inappropriately or becoming physically aggressive.

"Alcohol is still one of the deadliest drugs in our society," said Doug Tieman, Caron's President and CEO. "Our culture has normalized substance abuse to the extent that many people don't perceive significant consequences as cause for concern even though they can indicate serious problems. Many of the unintended victims, of course, are our children. We all need to be accountable for our behavior. But if you are an alcoholic, it's unlikely that you can change your behavior without significant help. You will need support to develop the skills and tools to lead a happy and productive life without alcohol."

Reducing the number of bars, restaurants, liquor stores and other locations where alcohol is sold in a community may help reduce domestic violence, a new study suggests.The findings come from research by the Centers for Disease Control and Prevention (CDC), which reviewed 16 previous studies that examined the link between alcohol sales in communities and rates of domestic violence. The investigators evaluated many factors, including the number of hours and days alcohol was sold, alcohol pricing and taxes, and the number of locations where alcohol was sold.

Only the number of alcohol sales outlets was consistently associated with rates of domestic violence, HealthDay reports. Most of the studies found a link between a greater number of locations where alcohol was sold and higher rates of domestic violence. The link held even when factors such as local poverty and unemployment rates were taken into account.