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Vol. LXV, No. 1
January 4, 2013
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Digest

Regular Marijuana Use by Teens Continues to Be a Concern

The Monitoring the Future survey showed that teens’ perception of marijuana’s harmfulness is down, which can signal future increases in use.
The Monitoring the Future survey showed that teens’ perception of marijuana’s harmfulness is down, which can signal future increases in use.

Continued elevated use of marijuana by the nation’s eighth, 10th and 12th graders was also combined with a drop in perceptions of its potential harms in this year’s Monitoring the Future survey, an annual survey of eighth, 10th and 12th-graders conducted by researchers at the University of Michigan. The survey was carried out in classrooms around the country under a grant from the National Institute on Drug Abuse.

The 2012 survey shows that 6.5 percent of high school seniors smoke marijuana daily, up from 5.1 percent 5 years ago. Nearly 23 percent say they smoked it in the month prior to the survey, and just over 36 percent say they smoked within the previous year. For 10th graders, 3.5 percent said they use marijuana daily, with 17 percent reporting past month use and 28 percent reporting use in the past year. The use escalates after eighth grade, when only 1.1 percent reported daily use, and 6.5 percent reported past month use. More than 11 percent of eighth graders said they used marijuana in the past year.

The Monitoring the Future survey also showed that teens’ perception of marijuana’s harmfulness is down, which can signal future increases in use. Only 41.7 percent of eighth graders see occasional use of marijuana as harmful; 66.9 percent see regular use as harmful. Both rates are at the lowest since the survey began tracking risk perception for this age group in 1991. As teens get older, their perception of risk diminishes. Only 20.6 percent of 12th graders see occasional use as harmful (the lowest since 1983), and 44.1 percent see regular use as harmful, the lowest since 1979.

Experimental Agent Briefly Eases Depression Rapidly in Test

A drug that works through the same brain mechanism as the fast-acting antidepressant ketamine briefly improved treatment-resistant patients’ depression symptoms in minutes, with minimal untoward side effects, in a clinical trial conducted by NIH. The experimental agent, called AZD6765, acts through the brain’s glutamate chemical messenger system.

Existing antidepressants available through prescription, which work through the brain’s serotonin system, take a few weeks to work, imperiling severely depressed patients, who can be at high risk for suicide. Ketamine also works in hours, but its usefulness is limited by its potential for dissociative side-effects, including hallucinations. It is being studied mostly for clues to how it works.

“Our findings serve as a proof of concept that we can tap into an important component of the glutamate pathway to develop a new generation of safe, rapid-acting practical treatments for depression,” said Dr. Carlos Zarate of the National Institute of Mental Health, which conducted the research. He and his colleagues reported on their results online Dec. 1, 2012, in the journal Biological Psychiatry.

New Test Offers More Information on Genetic Causes of Stillbirth

A more precise method for examining a fetus’ genetic material may help detect abnormalities in 40 percent more cases of stillbirth than does the traditional method, according to an NIH network study. A stillbirth occurs when a baby dies in the womb prior to delivery at or after 20 weeks of gestation. In the United States, stillbirth occurs in 1 of every 160 births.

When pregnancy ends in stillbirth, doctors may attempt to examine the baby’s chromosomes with a technique known as a karyotype. The karyotype is an image of an individual’s chromosomes and is used to look for an abnormal number of chromosomes or for abnormally shaped chromosomes. However, karyotyping requires cells to be grown in culture, which is often not possible in a stillbirth. So researchers sought a technique that would be more reliable.

They compared the results of karyotypes from more than 500 stillbirths to results from microarray analysis, a genetic method that detects small segments of missing parts of chromosomes (deletions) or additional sections of genetic material (duplications) that cannot be seen by karyotype.

The findings appeared in the New England Journal of Medicine.


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