Dishonest Science meets Irresponsible Journalism

One of the things that really worried me about the ridiculous gateway assertions in the rat study below was how some of the more gullible (or outright corrupt) media outlets would play the story.
And I was right to worry. Take a look at these headlines:

• Cannabis ‘can lead to harder drugs’
• Early cannabis abuse ‘does lead to heroin addiction’
• Study: Marijuana may lead to other drugs
• Adolescent Drug Users Turn Compulsive Addicts
• Cannabis Use May Lead To Heroin Addiction
• CANNABIS IS LINKED TO HEROIN Dope kids at risk
• ‘Dope Smokers More Likely To Use Hard Drugs’
• Study: Marijuana may lead to other drugs
• Early cannabis abuse ‘leads to heroin addiction’

Remember that the study found, at most, that rats pre-treated with THC are prone to self-administer heroin more frequently than control rats after both they and the control groups are forcibly addicted to heroin by the scientists. There was no indication that the THC-pretreated group was more likely to “use” hard drugs.
Yet these media morons manage headlines like “Dope Smokers More Likely To Use Hard Drugs.”
Interestingly, it’s possible that the study may not even show what the scientists claim. Drug WarRant commenter J speculates…

First of all, as Pete pointed out, the experimenters found no evidence that rats exposed to THC in adolescence became addicted to heroin more easily than controls [“vehicle”]. They did show that THC exposure did cause the rats to use more heroin. They also showed that when the lever used for self administering heroin was disconnected, the controls pushed the lever more than the THC exposed.

This may mean that the controls were “more addicted” and did not as easily give up on getting their fix as did the THC exposed.
So why would one group use more heroin, but give up more easily when they can no longer self administer? It seems to me that being less sensitive to heroin would explain both of these. The THC exposed need to use higher doses of heroin to get the same effect as the controls, but have an easier time giving up since the heroin isn’t as potent to them. This is exactly the opposite of the conclusion of the authors:

Heightened opiate sensitivity in THC animals was also evidenced by higher heroin consumption during the maintenance phase (30 and 60 mug/kg/infusion) and greater responding for moderate-low heroin doses (dose-response curve: 7.5, 15, 30, 60, and 100 mug/kg/injection).

It doesn’t make sense to me that heightened sensitivity would lead to more use, it should lead to less use. Tolerance leads to more use.
So this may actually be evidence of a counter-gateway theory. Either way, one thing is clear: rats that do heroin get decapitated.

Interesting points.
Anyone else care to chime in on this one?
… and that last point is a good one. Regardless of whether I had cannabis as a juvenile, if I was a rat in a cage being subjected to scientific experiments that end with my decapitation, I’d be pressing that heroin lever like crazy.