Carl Sagan was a marijuana user:
US: Wire: Biographer: Sagan Smoked Marijuana

In Edison's time there were many types of drugs available, including extremely strong cannabis, hash and hash oil-type preparations available at drug stores OTC. There were also dens for the "other" smokable stuff, which he may have indulged in. It wouldn't surprise me if he experimented with or even regularly used a drug or combination of drugs during his lifetime.