GABAergenics in general are pretty much the sole class of popular recreational drug which have a very real possibility of lethal withdrawals.
In the case of alcohol, it often takes years for addicts to reach a point where withdrawal becomes lethal. In the case of short acting benzodiazepines/barbiturates, this point can be reached in less than a month.
Of course, benzodiazepines are in schedule IV, which means they are viewed as being rather benign with no/low potential for abuse. In the eyes of the federal government, alprazolam (xanax) is far less dangerous than marijuana/the traditional psychedelics.
Just another data point demonstrating the utter absurdity of US drug legislation and regulation.
