Well, perhaps this fell under the auspices of "tolerance," but what the article was really talking about was very long-term use over decades and changes to the CB1 and CB2 receptors, neurotransmitters, and neurochemistry that occur over long periods of time, not just familiarity and frequent use of the substance leading to simple tolerance. A good many knowledgeable folks believe "tolerance" where cannabis is concerned is actually a myth.