Inhaled nitrous oxide, a party drug more commonly known as laughing gas, whip-its and "hippie crack," provides relatively intense, brief highs, although few people realize it also can harm, or even kill.
Despite a benign reputation for reducing users to peals of laughter, the colorless, sweet-smelling gas deprives the heart and brain of oxygen and can cause damage. Nitrous oxide use is what reportedly landed actress Demi Moore in the hospital this week, according to the website TMZ.com, which posted statements from a friend who was at the 49-year-old actress's home when she lapsed into semi-consciousness.
Moore's publicist on Thursday declined to comment beyond the statement issued earlier in the week that the actress was receiving medical treatment.
"Because of the stresses in her life right now, Demi has chosen to seek professional assistance to treat her exhaustion and improve her overall health. She looks forward to getting well and is grateful for the support of her family and friends," her rep said in an email to ABCNews.com.
Nitrous oxide interacts with the brain's reward system to cause "out-of-body, mild, hallucinatory, euphoric-type stuff," said Dr. Terry Horton, chief of addiction medicine at Christiana Care Health System in Wilmington, Del. "To some folks, that's appealing."
The buzz is fleeting, lasting just a minute or two, while "the potential dangers are many," Horton told ABCNews.com. Although Horton wasn't involved in Moore's treatment and wasn't familiar with the specifics of her case, he said coverage of nitrous oxide's effects on Moore could underscore its dangers, or backfire "if there's a sense out there that whip-its are not going to cause problems, and this PR perpetuates that."
Nitrous oxide use can be particularly dangerous for someone who has a history of abusing drugs or alcohol, according to Denise Carise, chief clinical officer at the Phoenix House Foundation in New York. "Often, the use of one drug can lead to the use of the person's drug of choice and new problems," she said. "We don't often see fatalities or brain damage from the abuse of nitrous oxide in isolation, but it's use is often associated with drinking and other risky behavior that can cause serious problems."
Nitrous oxide has legitimate uses as a mild anesthetic and pain-reliever, an engine booster in auto racing and rocketry, and to dispense whipped cream from pressurized spray cans (which is the source of its nickname -- written whip-its, whippits or whippets). Easily accessible, relatively inexpensive and generally legal -- although many states restrict sales to minors -- nitrous oxide has escaped the bad rap of other mood-altering drugs. Sir Humphry Davy, the British chemist who discovered its anesthetic properties in 1799, reported becoming intoxicated after breathing 16 quarts of the gas for almost seven minutes. Through much of the 1800s, it remained a largely recreational drug among poets and aristocrats, and had another surge of popularity among beat generation writers and artists of the 1950s.
Today, however, nitrous oxide is largely used by teenagers and young adults who inhale it from balloons they either fill from large tanks or from pressurized cans and cylinders. Law enforcement agencies, such as the Anaheim, Calif., Police Department, have been warning parents of increasing abuse, including two cases of suicide linked to the gas in September 2010. Mental health professionals worry about its effects on youngsters' developing brains, and indications that it can be a gateway to other drugs for them. The Massachusetts Department of Public Health has sought to reduce its availability by asking wholesale distributors to limit sales to legitimate users and asking retail sellers to monitor sales of canned whipped cream and whipped cream chargers, the small cylinders of nitrous oxide used in whipped cream dispensers.
Horton said that nitrous oxide's potential long-term effects include interference with vitamin B-12, which can lead to a type of anemia, as well as damage to many parts of the nervous system.
"You can hypothesize that if someone was using this chronically, and they kept doing it, they could end up with some permanent nerve damage that might affect them all the way up to their ability to think," he said.
The jury remains out about whether nitrous oxide is truly addictive. "Those who inhale the Gas once are always anxious to inhale it the second time," reads a line in an 1845 handbill promoting a "Grand Exhibition" of laughing gas effects.
Anecdotal reports indicate people "develop dependence and behavioral changes that are suggestive of addiction," Horton said.