Although legal in the US and UK, alcohol was scored by Nutt et al.’s experts 1.9 out of a maximum of 3. Alcohol has many effects on the brain, but in laboratory experiments on animals it increased dopamine levels in the brain’s reward system by 40% to 360% — and the more the animals drank the more dopamine levels increased.
Some 22% of people who have taken a drink will develop dependence on alcohol at some point during their life. The WHO has estimated that 2 billion people used alcohol in 2002 and more than 3 million people died in 2012 due to damage to the body caused by drinking. Alcohol has been ranked as the most damaging drug by other experts, too.