Evidence "Reefer Madness" was right?

A study published this month in the Archives of General Psychiatry concludes that "early cannabis use is associated with psychosis-related outcomes in young adults".

Compared with those who had never used cannabis, young adults who had 6 or more years since first use of cannabis (ie, who commenced use when around 15 years or younger) were twice as likely to develop a nonaffective psychosis and were 4 times as likely to have high scores on the PDI.
(Note: PDI refers to the Peters et al Delusions Inventory)

This study used sibling pairs to reduce the likelihood that unmeasured genetic and environmental factors explained the findings, a criticism that had been made of previous studies which also found a link between marijuana use and psuychosis.The seven previous studies finding this effect and referenced by the study are:

1. Andréasson S, Allebeck P, Engstrom A, Rydberg U. Cannabis and schizophrenia: a longitudinal study of Swedish conscripts. Lancet. 1987;2(8574):1483-1486.

2. Zammit S, Allebeck P, Andreasson S, Lundberg I, Lewis G. Self reported cannabis use as a risk factor for schizophrenia in Swedish conscripts of 1969: historical cohort study. BMJ. 2002;325(7374):1199.

3. van Os J, Bak M, Hanssen M, Bijl RV, de Graaf R, Verdoux H. Cannabis use and psychosis: a longitudinal population-based study. Am J Epidemiol. 2002;156(4):319-327.

4. Henquet C, Krabbendam L, Spauwen J, Kaplan C, Lieb R, Wittchen HU, van Os J. Prospective cohort study of cannabis use, predisposition for psychosis, and psychotic symptoms in young people. BMJ. 2005;330(7481):11.

5. Weiser M, Reichenberg A, Rabinowitz J, Kaplan Z, Caspi A, Yasvizky R, Mark M, Knobler HY, Nahon D, Davidson M. Self-reported drug abuse in male adolescents with behavioral disturbances, and follow-up for future schizophrenia. Biol Psychiatry. 2003;54(6):655-660.

6. Arseneault L, Cannon M, Poulton R, Murray R, Caspi A, Moffitt TE. Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study. BMJ. 2002;325(7374):1212-1213.

7. Fergusson DM, Horwood LJ, Swain-Campbell NR. Cannabis dependence and psychotic symptoms in young people. Psychol Med. 2003;33(1):15-21.

The popular culture seems to have embraced the idea that making an association between marijuana use and psychosis is ludicrous, as exemplified by the ridiculing of the 1930's film Reefer Madness. But now it seems contemporary medical studies confirm that film's eponymous claim.

USA: 1 in 110 children diagnosed on autism spectrum

A new CDC study of American eight year olds in 2006 found that about 1% had been diagnosed on the Autism spectrum (ranging from full autism to Asberger's disease). The prevalence in boys is 4 to 5 times the prevalence in girls. In Missouri, almost 2% of eight year old boys have been diagnosed on the autism specturm.

TIME magazine's article reporting on the study distinguishes between increases due to increased awareness and diagnoses versus increases due to an underlying increase in the condition.

Previous studies looking at a narrower population of youngsters have suggested that as much as 40% of the rise in autism cases might be explained by broader diagnostic definitions and by heightened awareness of the condition. But that still leaves 60% of the increase unaccounted for. "Most scientists believe there is something more than just awareness and a broadening definition that is responsible for the rise," says Dr. Gary Goldstein, president of the Kennedy Krieger Institute in Baltimore. "We are seeing some fraction of the increase that is probably due to more cases of autism."

TIME goes on to provide to specify some of the possible causes, focussing on the mother:

Since autism is generally diagnosed before age two, most scientists believe the factors that contribute to ASD occur during pregnancy, or in the months immediately following birth. A pregnant mother's advanced age might be one such influence, along with certain behavioral and environmental exposures she or her newborn baby may experience — any combination of which could be interacting with their particular genetic makeup to promote ASD. Isolating the most causative culprits will be a challenge, say autism experts. "There is so much stuff out there, whether it is diet or infection," says Goldstein. "We could make a list but it's got thousands of things on it."

The Wall Street Street Journal cites Catherine Rice, the CDC scientist who is the study's lead author, on the possible environmental factors leading to the increase:

Dr. Rice also said she couldn't rule out an actual increase in the number of autistic children. Research is under way into possible environmental factors, including vaccinations, household products and diet, as well as genetics, for potential causes, she said.

The Wall Street Journal also cites a source for the possibility that the age of the fathers may be a factor :

Philip Levy, president of YAI Network, a New York-based nonprofit that serves people with disabilities, including autism disorders, said the report confirmed that autism is "a continuing national health crisis." He added that some societal factors were helping to increase the risk of diagnosis. "With fathers in particular, there's a stronger correlation that has been made between older fathers and autistic children," Mr. Levy said.

San Francisco: Constant Battle Against Bedbugs

In addition to concerns about old diseases coming back, we have insects I thought were "myths" turning out to exist. The San Francisco Chronicle reports that bedbugs are real, and they are real hard to get rid of:

When she and her husband moved into an upscale apartment in an "emerging" neighborhood near Civic Center, Katie Beckheyer may have had some concerns about crime, gritty streets and panhandlers. But she never expected what would be the real nightmare.

Bedbugs.

"I am covered in itchy red welts," she said in an e-mail, "and drained to the core from six months of insomnia, paranoia (I wake up every morning at 3 a.m., searching my sheets for signs of them feeding on me) and incessant itching."

Beckheyer had their apartment sprayed six times. But they were still getting bitten, so they finally paid for one last treatment to make sure their belongings were clean, and then moved out.

Before you extend sympathetic wishes to the poor folks who are infested with bedbugs, here's a piece of advice - better check your mattress.

Like the rest of the country, San Francisco is experiencing a bedbug boom. Dr. Johnson Ojo of the Department of Public Health said bedbugs are popping up everywhere, from "low-income housing to high-priced hotels."

It's an all-out war on the tiny, creepy, blood-sucking predators. And the bugs are winning.

Read it all.

Shared Genetic Variation for 65% of People with Autism

The Los Angeles Times is reporting on a new study published in the journal Nature:

The first of two Nature studies released Tuesday found that 65% of autistic participants shared a variation between cadherin 10 and cadherin 9, a region of the genome that controls cell-adhesion molecules in the brain. Those molecules help brain cells connect, and autism researchers have long suspected that trouble there may be linked to the disorder.

However, as Science News reports on the study, the variation is also shared by more than half of of people without autism:

One of the new studies encompasses more than 14,000 people and has uncovered a variant found in about 65 percent of people with autism. More than half of people without autism or related disorders also have the variant, indicating that other genes and environmental factors are necessary to trigger autism. Still, the variant may account for up to 15 percent of autism cases, a team led by researchers at the Children’s Hospital of Philadelphia and the University of Pennsylvania School of Medicine, also in Philadelphia, reports online April 28 in Nature.

Some people have suspected that the mercury was used as a preservative in some children's vaccines was the environmental factor triggering the increase in the number of autistic children. This theory has been discredited, but no competing theory has been provided. What explains the high incidence of autism among Somali children in Minnesota?

Swine Flu from Cancun

I've been noticing that the cases of swine flu in Sacramento, New York and Nova Scotia seem to have been contracted from Cancun and the Yucatan Peninsula. Cancun is the large tourist destination of the Yucatan Peninsula.
UPDATE: Add the cases in Vancouver and Scotland to those contracted in Cancun.

As the San Jose Mercury News reports:

Dawn and Iain Askham became ill over the weekend, a few days after returning from Cancun.

And from the Vancouver Sun:

Ryan said he flew to Cancun on April 14 with a friend, but began feeling sick before his return flight last Wednesday.

The cases of swine flu in New York are associated with a trip to Cancun, according to the Sun Times:

Some of the Queens students had recently traveled to Cancun.

And from this San Francisco Chronicle article:

A seventh-grader at St. Mel who recently returned from a family vacation to Cancun, Mexico, felt ill last Monday and went home. On Wednesday, a classmate also missed school with flulike symptoms, and by Friday seven students were out, including four who complained of flulike symptoms, said Kevin Eckery, a spokesman for the Catholic Diocese of Sacramento.

Note that it is not yet confirmed that this Sacramento case is swine flu

The Nova Scotia cases are also associated with the Yucatan Peninsula although the city of Cancun is not specifically mentioned:

Earlier, Nova Scotia's chief public health officer, Dr. Robert Strang, said the National Microbiology Laboratory in Winnipeg confirmed late Saturday that four young people in the province are recovering from "relatively mild" cases of the H1N1 virus.
Strang said the four are between the ages of 12 and 18 and all attend King's-Edgehill School in Windsor, N.S. However, only one of those students had been on a recent school trip to Mexico's Yucatan Peninsula, headmaster Joe Seagram later told reporters.

More Cases of Measles in US Capitol

Are you as surprised as I am to see these old childhood diseases are not eradicated in our nation's capitol? The Washington Post is reporting that there have been five cases of measles in the region this year:

Health officials said today that a D.C. man was diagnosed with measles late last week, prompting authorities to retrace the his steps throughout the area to identify anyone else who may have exposed to the highly infectious disease and prevent it from spreading further.

This is the fifth case of measles in the region this year, but it is not related to the other cases. Still, the rare outbreak has prompted health officials in the District, Virginia and Maryland to focus on the small pockets of unimmunized individuals: Mostly, babies who have not yet been vaccinated and people who were born outside the U.S.

The District man contracted the virus during a three-week trip to India but did not show symptoms until after he returned home, said D.C. Department of Health Director Pierre Vigilance. Doctors believe the man's wife also has measles but they are still awaiting test results. Vigilance said the man had never been immunized, but wouldn't comment on his citizenship or why he had not been immunized.

Over at Little Green Footballs, Charles Johnson has been posting stories about people who don't get there children vaccinated because of concerns that the mercury in the vaccinations may cause autism. Some of the commenters have noted that in some Islamic communities, people are also suspicious of vaccinations.

This Washington Post article indicates that there is a problem of adults who have not been vaccinated because they are from countries where vaccinations are not normative. The Washington Post article does say that vaccinations are required to get citizenship and for children entering public school. I think most private schools also require the vaccinations.