(TNN) - A new study in the medical journal “The Lancet” highlights the five most addictive substances.
Their number one is heroin, an opiate that can cause the level of dopamine in the brain to increase as much as 200-percent.
Number two is cocaine, which prevents neurons in your brain from shutting off dopamine signals.
Number three is nicotine, which is rapidly absorbed in the lungs and sent to the brain.
Barbiturates, or downers, are number four. They interfere with signals in the brain, causing certain regions to shut down, and are often used to treat anxiety disorders.
Their number five is alcohol. According to the study, 23 percent of people who have tried it develop a dependence.