I once met a guy who encountered major emotional pain when his wife left him, and had to go to therapy because of a running addiction. It was also causing physical health problems like purple swollen feet. Anything can be addictive "compulsive engagement in rewarding stimuli, despite adverse consequences" is the definition. Lots of people have used drugs to propel their career and avoided addiction. For example, Steve Jobs said taking LSD was one of the most important things he had ever done in his life.... Although I've never heard of an LSD addiction, there's lots of profound people who used cannabis habitually.