It turns out the gateway drug for amphetamine addiction is a substance provided by your own brain. The culprit protein is called DAT, so named because it is a dopamine transporter — and dopamine is the feel-good, get-motivated neurotransmitter that keeps you happy, hungry, and full of energy. Just as some people are born with the ability to grow larger muscle mass than others, some are born with the ability to squirt more dopamine into their brains because they have a greater-than-average helping of DAT. People with elevated DAT levels are quite literally better at getting high than people with average levels. How do we know? A group of researchers in North Carolina and Pennsylvania recently bred a group of mice to have DAT levels three times above normal and then gave them speed. Here's what happened.

According to the Proceedings of the National Academy of Sciences:

Ali Salahpour and colleagues explored the impact of DAT levels on the response to amphetamines—a group of addictive chemicals closely tied with dopamine sensitivity. Amphetamines are used legally to treat ADHD, narcolepsy, and to suppress appetite, but are well-known as illicit "club" drugs and performance enhancers. To investigate the consequence of high DAT levels, the researchers developed transgenic mice with three-fold higher levels of DAT compared with unmodified animals. The authors discovered that the drug was more powerful in animals with more DAT. The dopamine-enhanced animals were more sensitive to the effects of amphetamines, becoming hyperactive and more rewarded by the drug, according to the authors.


Tinkering with DAT levels is something that researchers are already trying in order to deal with things like hyperactivity and depression. Now it seems there might be a street value for DAT-enhancers. Take a hit of DAT, snort a line of speed, and you'll get more bang for your buck. Image via Paul De Koninck.

Increased Amphetamine-Induced Hyperactivity [PNAS]