Parent to their teenage child:
'Now son/daughter, let's do a little cost-benefit analysis of smoking in case you're thinking of taking it up as your new hobby like your friends.
Costs- a cigarette is tobacco leaves (which are held sacred in their natural state in many ancient tribes and used in rituals) wrapped in paper and covered in around 600 approved chemicals, 70 of which have been found to cause cancer. Among the delightful chemicals that those lovely people at the tobacco company put in your expensive cancer sticks are those used in batteries, candle wax, industrial solvent, insecticide, toilet cleaner, rocket fuel, sewer gas, and just for added effect, arsenic! Smoking kills around 5 million people a year worldwide and is expensive and heavily taxed. Aside from the smell, which the smoker generally isn't exposed to because their sense of smell is affected, your teeth are going to turn yellow, you won;t be able to run a flight of stairs without wheezing, your lungs will go black, your blood pressure will be increased, the optic nerve in your eyes will be affected as will your reproductive system and numerous other internal systems, and you are going to face a vastly-increased chance of heart disease and heart-related chest pain.
Benefits- you'll look f***ing cool and everyone will think you're a true rebel!'
At the end of the day, we all self-medicate, but maybe a little investigation and analysis of the root causes of our suffering might be an idea.