1 cigarette a week If you want to quit smoking, here's something to motivate you. : r The Effect of 12-Week e-Cigarette

Tolerance Building: Needing to use more cannabis over time to achieve the same effects

An additional 23 states allow for medical marijuana prescriptions and use

-If you have oral and tactile cravings, you can keep your hands busy playing with squeeze balls or pencils, chew sugar-free gums, drink water, or eat fruits when you want to have a smoke

Penalties are broadly similar in Scotland, Wales and Northern Ireland

Nicotine constricts the flow of blood and oxygen to the gums and acts as a stimulant, both of which can cause issues with dental health

Electronic cigarettes may also be partly responsible for the decline, Healton says