Research has shown that the faster a drug reaches the brain, the more likely it is to be addicting. Different methods of delivery smoking, injecting, or snorting largely influence how quickly a drug reaches the brain. Delivery methods, genetics, and environment all influence the potential of a drug to cause addiction.

The Fastest Way to the Brain

The fastest way to get a drug to the brain is by smoking it. When a drug like tobacco smoke is taken into the lungs, nicotine (the addictive chemical in tobacco) seeps into lung blood where it can quickly travel to the brain. This fast delivery is one reason smoking cigarettes is so addicting. Injecting a drug directly into a blood vessel is the second fastest way to get a drug to the brain, followed by snorting or sniffing it through the nose. A slow mode of delivery is ingestion, such as drinking alcohol. The effects of alcohol take many minutes rather than a few seconds to cause behavioral and biological changes in the brain.