Drugs of dependence come in a variety of forms. Opiates are the most commonly associated with overdose deaths. Nicotine addiction is one of the most difficult to overcome. Sedatives like Xanax, Ativan, Valium, and Klonopin become easily habit-forming. Then there are the sleep aids Ambien, Lunesta and Sonata that initially may appear beneficial, often losing effectiveness over the long term.

Cocaine use is also ubiquitous as is marijuana. Use of the latter has always been controversial. Only recently has the FDA finally begun studies, trying to evaluate whether it might have health benefits without safety concerns. At this time, however, it is still considered illegal on the federal level, though many states have individually legalized it.