Monthly Archives: June 2016

Risk for Early Psychosis

images-7Psychotic illness occurs significantly earlier among marijuana users, results of a meta-analysis suggest.

Data on more than 22,000 patients with psychosis showed an onset of symptoms almost three years earlier among users of cannabis compared with patients who had no history of substance use.

The age of onset also was earlier in cannabis users compared with patients in the more broadly characterized category of substance use, investigators reported online in Archives of General Psychiatry.

“The results of this study provide strong evidence that reducing cannabis use could delay or even prevent some cases of psychosis,” Dr. Matthew Large, of the University of New South Wales in Sydney, Australia, and co-authors wrote in conclusion.

“Reducing the use of cannabis could be one of the few ways of altering the outcome of the illness because earlier onset of schizophrenia is associated with a worse prognosis and because other factors associated with age at onset, such as family history and sex, cannot be changed.”

Psychosis has a strong association with substance use. Patients of mental health facilities have a high prevalence of substance use, which also is more common in patients with schizophrenia compared with the general population, the authors wrote.

Several birth cohort and population studies have suggested a potentially causal association between cannabis use and psychosis, and cannabis use has been linked to earlier onset of schizophrenia. However, researchers in the field remain divided over the issue of a causal association, the authors continued.

Attempts to confirm an earlier onset of psychosis among cannabis users have been complicated by individual studies’ variation in methods used to examine the association. The authors sought to resolve some of the uncertainty by means of meta-analysis.

A systematic search of multiple electronic databases yielded 443 potentially relevant publications. The authors whittled the list down to 83 that met their inclusion criteria: All the studies reported age at onset of psychosis among substance users and nonusers.

The studies comprised 8,167 substance-using patients and 14,352 patients who had no history of substance use. Although the studies had a wide range of definitions of substance use, the use was considered “clinically significant” in all 83 studies. None of the studies included tobacco in the definition of substance use.

The studies included a total of 131 patient samples.

Substance use included alcohol in 22 samples, cannabis in 41, and was simply defined as “substance use” in 68 samples.

Alcohol use was not significantly associated with earlier age at onset of psychosis.

On average, substance users were about 2 years younger than nonusers were. The effect of substance use on age at onset was greater in women than in men, but not significantly so. Heavy use was associated with earlier age at onset compared with light use and former use, but also not significantly different, the authors reported.

Substance users were two years younger at the onset of psychosis compared with nonusers. Age at onset was 2.7 years earlier among cannabis users compared with nonusers.

Amourous Mice

No pill should be digested before its time — or it’s proper location, which sounds simple, but is nonetheless a challenge for drug makers. But a solution may be at hand: a magnetic addition to glycerin capsules could eliminate the problem of undigested pills.

In rats, an external magnet could hold the magnetized pills where they would be best digested in the intestine, according to a study in the Proceedings of the National Academy of Sciences. Prolonging that “intimate contact” between dose and intestine, as the researchers put it, could boost absorption of oral vaccines and medicines, such as agents for inflammatory bowel disease or GI cancers. Many drugs are optimally absorbed at specific sites in the intestine. The study wasn’t the first to try magnetic control, but it stood out in trying to make the process safer.

The system actively controlled the force between the pill and the external magnet, and it monitored the pill’s location with real-time videofluoroscopy.

Although it was safe in the rats tested, the researchers said they ultimately want to hone their pills’ magnetic attraction for use in the outpatient setting.

— Crystal Phend

Playing the Field Pays Off for Mice

Mice that mated with multiple partners gave birth to more fertile male offspring, according to an Australian study that provided the most compelling evidence yet of a hypothesized benefit of promiscuity.

Litters produced during a study of sperm competition exhibited a “significant paternity bias” favoring fathers from a polygamous lineage. Previous studies had shown that the ejaculate of polygamous males had a significantly higher sperm count and greater motility compared with ejaculate from monogamous male mice, as reported online in BMC Evolutionary Biology.

The findings support the hypothesis that higher sperm quality translates into a competitive advantage in reproduction, according to Renee Firman, PhD, and Leigh Simmons, PhD, of the University of Western Australia in Nedlands.

The investigators examined the concept of sperm competition through 12 generations of house mice. The studies compared two groups of mice: one in which females had access to multiple male partners and one in which each female had access to a single male partner.

Previous studies showed that females from the polygamous environment had larger litters, even though females in both groups were releasing the same number of eggs per cycle. Subsequent studies revealed the superior sperm quality among males from the polygamous lineage.

The final test was a mating competition, whereby female mice mated with one polygamous male and one monogamous male during ovulation. Firman and Simmons found that more than twice as many litters were fathered exclusively by polygamous male mice versus monogamous males (33 percent versus 14 percent). The remaining litters exhibited mixed paternity.

Health Reform Law

A federal judge ruled Monday that the new U.S. health-care reform law is unconstitutional, saying the federal government has no authority to require citizens to buy health insurance.

That provision is a cornerstone of the new legislation, signed into law in March by President Barack Obama.

The judge’s decision was not unexpected, and both supports and opponents of the legislation anticipate the validity of the new health law ultimately will be decided by the U.S. Supreme Court.

The ruling was handed down by U.S. District Judge Henry E. Hudson, a Republican appointed by President George W. Bush who had seemed sympathetic to the state of Virginia’s case when oral arguments were heard in October, the Associated Press reported.

Last week, White House officials said a negative ruling would not affect the implementation of the law because its major provisions don’t take effect until 2014, the AP reported.

Virginia Attorney General Kenneth Cuccinelli, a Republican, had filed a lawsuit in defense of a new Virginia law barring the federal government from requiring state residents to buy health insurance. He argued that it is unconstitutional for the federal law to force citizens to buy health insurance and to assess a penalty if they don’t.

The U.S. Justice Department said the insurance mandate falls within the scope of the federal government’s authority under the Commerce Clause. But Cuccinelli said deciding not to buy insurance is an economic matter outside the government’s domain.

By 2019, the law will expand health insurance access to 94 percent of non-elderly Americans. Advocates say that between now and then, it will also provide Americans with many new rights and protections.

Spreads Outside Hospitals

C. difficile is a deadly diarrheal infection that poses a significant threat to U.S. health care patients,” Ileana Arias, principal deputy director at the U.S. Centers for Disease Control and Prevention, said during a morning news conference. “C. difficile is causing many Americans to suffer and die.”

The germ is linked to about 14,000 deaths in the United States every year. People most at risk from C. difficile are those who take antibiotics and also receive care in any medical facility.

“This failure is more difficult to accept because these are treatable, often preventable deaths,” Arias said. “We know what can be done to do a better job of protecting our patients.”

Much of the growth of this bacterial epidemic has been due to the overuse of antibiotics, the CDC noted in its March 6 report. Unlike healthy people, people in poor health are at high risk for C. difficile infection.

Almost 50 percent of infections are among people under 65, but more than 90 percent of deaths are among those aged 65 and older, according to the report.

Previous estimates found that about 337,000 people are hospitalized each year because of C. difficile infections. Those are historically high levels and add at least $1 billion in extra costs to the health care system, the CDC said.

However, these estimates might not completely reflect C. difficile’s overall impact.

According to the new report, 94 percent of C. difficile infections are related to medical care, with 25 percent among hospital patients and 75 percent among nursing home patients or people recently seen in doctors’ offices and clinics.

Although the proportion of infection is lowest in hospitals, they are at the core of prevention because many infected patients are transferred to hospitals for care, raising the risk of spreading the infection there, the CDC said.

Half of those with C. difficile infections were already infected when they were admitted to the hospital, often after getting care at another facility, the agency noted.

The other 50 percent of infections were related to care at the hospital where the infection was diagnosed.