Autism and antidepressants

What are the reasons for the more than six-fold increase in reported cases of autism in the past 20 years? Changes in diagnostic criteria are thought to account for up to 25% of the increased number of cases. Increased awareness of the condition may also mean that more autistic children are being diagnosed as having the condition; some of these children that might have been missed in the past. And there is some evidence that parents of advanced age are more likely to have an autistic child, accounting for some of the cases. Finally, some parents continue to believe (against an overwhelming body of scientific literature) that autism may be caused by something related to childhood vaccinations, and so they refuse to have their children vaccinated. It’s as if lacking an adequate explanation, they’d rather clutch at straws rather than admit that we just don’t know yet.

Two recent studies suggest that some cases of autism may (and I stress may) be related to the mother’s use of certain antidepressant medications during pregnancy. The most recent study is out of Sweden, where national health statistics make large population studies feasible.

The results should be interpreted with caution, however. It will prove difficult to separate out whether it’s the mother’s clinical depression itself, or the drugs used to treat it, that may be increasing the risk of autism. After all, women generally don’t take antidepressants unless they’re clinically depressed. It will be some time before we have a definitive answer, if ever. In the meantime, women who are clinically depressed should discuss the risks and benefits of antidepressant drugs with their physician if they anticipate becoming pregnant.

One final note: the use of antidepressants can’t account for much of the overall rise of autism, because so few pregnant women actually need and use antidepressants. The Swedish study points out that although any woman who uses antidepressants during pregnancy may be doubling the risk of autism in her child, the use of antidepressants during pregnancy probably accounts for less than 1% of all cases of autism in the whole population.

FDA Blocks Generic Oxycontin

When a drug’s original patent expires, the FDA usually approves generic versions of the drug.  There are winners and losers when this happens.  Patients win because generics cost less than the patented drug.   Generic drug manufacturers win too.  The only loser is the original patent-holder, whose profits usually fall dramatically when a blockbuster drug’s patent expires.  But don’t feel too bad for them; they’ve made plenty of profit from the drug already.  The high profit they make while the drug is under patent protection (up to 20 years) is supposed to compensate them for the high costs of drug development and testing, which the generic drug companies don’t need to do.

That’s how it usually works.   But this week the Food and Drug Administration (FDA) refused to approve a generic version of the popular pain-killing drug OxyContin, on the very day that the drug’s patent was set to expire.   Why?   OxyContin (a narcotic) has become an abused prescription drug, in part because the pills could be crushed and then injected or snorted, releasing high levels of narcotic all at once.   The FDA feared that widespread availability of generic OxyContin would lead to even more abuse of the drug.  So in an unusual move, the FDA chose instead to approve a newly-patented, reformulated version of OxyContin that is harder to abuse.   When crushed, the new OxyContin becomes a jelly-like mass that can’t be injected or snorted.  The potential safety benefits of the newer version were so compelling that the FDA was willing to phase out the old version.

But don't expect the old version of OxyContin to disappear just yet.  It turns out that generic OxyContin has been approved for sale in Canada.   Canadian pharmacies are likely to have it for sale within a month.

Workout Supplement Ingredient Banned

The Food and Drug Administration (FDA) issued a warning last week that several workout-booster and fat-burning products should be pulled from the market immediately because they contain an ingredient called DMAA (dimethylamylamine). The products, Jack3D (pronounced Jacked) and OxyElite Pro, are both marketed by USPlabs.

Back in 2011 the FDA sent letters to all 10 marketers of DMAA products, asking them to voluntarily stop marketing such products. All but USPlabs complied. The company continues to claim that the products are safe and legal.

According to the FDA, there have been 86 reports of health problems, including 5 deaths, among persons taking products containing DMAA. That does not prove that DMAA is dangerous, of course, and its not even the primary reason the FDA is asking that the products be removed from shelves. The FDA simply argues that DMAA does not fit the legal definition of a dietary supplement, and therefore it cannot be sold without prior FDA approval. I would agree; it's a drug. DMAA was actually developed by a pharmaceutical company in the 1940s and sold as a nasal decongestant until the 1980s. It stretches credulity a bit to suggest that it is a natural “supplement to the diet” when added to a workout-boosting product.

Judge Rules the Morning-After Pill Must be Made Available

What happens when politics and science clash? You may recall that back in 2011 the Food and Drug Administration (FDA) recommended that the morning-after pill known as Plan B be made available without a prescription to all women, including those under the age of 17. The FDA’s recommendation was based on good scientific evidence that the pill was both safe and effective. But then the Secretary of the Department of Health and Human Services (DHSS) nixed the idea for what appeared to be political reasons (see this blog, Dec. 11, 2011). The FDA is a government agency within DHSS, so the secretary of DHSS effectively overruled the FDA.

The decision pleased conservatives and pro-life groups. But it didn’t end there. The Center for Reproductive Rights filed a lawsuit against the 17-and-older age restriction, and the whole issue went to court. Finally, just last week a U.S. District Court judge ruled that the morning-after pill must be made available to women of all ages. Judge Edward Korman wrote in his opinion that the pill is being withheld from younger women due to “political pressure emanating from the White House.”

The morning-after pill could become made available to women of all ages within a month, unless the decision is appealed - first to the U.S. Court of Appeals and then perhaps the U.S. Supreme Court. This may not be over yet.

New Bird Flu Virus, H7N9

A second strain of bird flu virus, called H7N9, has now made the jump from birds to humans. According to the World Health Organization (WHO), there have been 18 reported cases of human infection so far, all in China. Six people have died.

Like the other bird flu virus (H5N1), the H7N9 virus is not capable of being transmitted from human to humans.  But unlike H5N1, the new H7N9 virus is not very virulent in birds. That makes it more difficult to detect than H5N1 (which kills most infected birds), because birds infected with H7N9 may not even appear to be sick. In humans, however, six deaths out of 18 infections is pretty virulent!

Authorities in China are handling this new outbreak better than they did the original outbreak of H5N1. The Chinese authorities are informing Chinese citizens, working with health officials around the world, closing bird markets in infected areas and slaughtering birds when it is deemed advisable. 

The U.S. is monitoring the situation and is working on a vaccine. In the meantime, the virus seems to be treatable with Tamiflu.

By the way, have you ever wondered how flu viruses get their unique names of letters and numbers? All Type A influenza viruses have two types of proteins on their surface, called hemagglutinin (H) and neuraminidase (N). Each of these proteins comes in multiple forms (16 different forms of H and 9 different forms of N are known in birds). So every flu virus's name reflects its unique combination of H and N protein forms. That’s probably more than you wanted to know, but at least it will make their names less mystifying to you.

Soot Contributes to Global Warming

According to recent research, the second-most significant contributor to global warming (after carbon dioxide), is not methane, as previously thought.  It’s carbon-black, also known as soot.  Black soot contributes to global temperature by absorbing sunlight and converting it to heat.  Soot is especially damaging when it falls on frozen and snow-covered regions of the Earth, because it causes snow and ice to melt more rapidly than they would otherwise.  Soot may be the reason why arctic ice is melting much faster than most climate models had predicted, based on elevations of greenhouse gases alone.

The good news is that correcting the climate problem caused by soot would be easier than dealing with methane and carbon dioxide.  Soot is a solid, so it is removed from the atmosphere much more quickly than either methane or carbon dioxide.  Within weeks of soot’s emission, it simply falls to the surface of the earth, whereas carbon dioxide and methane may hang around in the atmosphere for years.  In addition, most of the soot comes from diesel engines, inefficient stoves, and dirty diesel fuel; all problems that could be dealt with fairly easily if we had the will to do so.  Improving the efficiency of diesel engines to reduce soot emissions would have a significant impact within weeks.

You can read the entire comprehensive study of soot and its role in climate change in the Journal of Geophysical Research: Atmospheres.  But I warn you; it’s 286 pages long!  For a quick look, read the abstract.