I chose caffeine as an uncontroversial example, to demonstrate the breadth of the spectrum. I am not equating them; indeed it was chosen for maximum contrast.

Everyone on this planet does things to alter their mental state and status, from running, to masturbation, to coffee, to meditation, to SSRIs from the pharmacy, to drink, to cigarettes, to recreational illicit stimulants like cocaine, to intravenous heroin from the streetcorner. I could plot a continuous curve between the extremes, and it isn't any of our place to say where "therapy" ends and "addiction" starts for any other person, because of the wide range of procedures, practices, frequencies, dosages, and effects, both positive and negative.