There's no shortage of addictive substances, but some are more dangerous than others.

Here are the five most addictive substances, according to a study in the medical journal 'The Lancet.'

1) Heroin: It's an opiate that can cause the level of dopamine in the brain to increase as much as 200-percent.

If you take a dose five times bigger than the amount you need to get high, it can kill you.

2) Cocaine: Cocaine prevents neurons in your brain from shutting off dopamine signals.

About 21-percent of people who try it become addicted to it.

3) Nicotine: Nicotine is rapidly absorbed in the lungs and sent to the brain.

It is so addictive, more than two-thirds of Americans who try smoking become dependent at some point.

4) Barbiturates, also called "Downers"

Initially used to treat anxiety disorders, barbiturates interfere with signals in the brain, causing certain regions to shut down. 

While low doses can cause euphoria, higher doses can suppress your breathing, with lethal consequences.

5) Alcohol: It's not only legal, it's socially acceptable. 

Like harder drugs, alcohol also raises dopamine levels in the brain. 

About 23-percent of people who have tried alcohol will develop a dependence on it.

According to the World Health Organization, more than 3 million people died in 2012  due to damage to the body caused by alcohol.