I read an article summarizing studies of addiction a number of years ago that was quite interesting in this regard. Researchers scanned the brains of addicts while they were presented with pictures of the source of their addiction. Certain areas of the brain lit up (or whatever--the science was beyond me), showing the intensity of the addiction. Interestingly, the pattern of brain response was the same for all addictions. More interestingly, it was true for things we have jokingly called addictions as well--like shopping. Apparently anything we obsess over in a manner similar to what we call addiction stimulates the brain in the same way as addiction. We can indeed become essentially addicted to anything. Maybe even diving.You can develop an addiction to marijuana, or the THC it contains. You can also become habituated, requiring a higher dose to get the same effect.
The author of the article was a recovering alcoholic who had been sober for 25 years. He was tested, and when shown pictures of his former favorite alcoholic beverage, his brain had no response--the same as a non-drinker. He was essentially cured, but he was not going to take any chances.