[1] The traditional medical model of disease requires only an abnormal condition causing distress, discomfort or dysfunction to an affected individual.
The contemporary medical model partly attributes addiction to changes in the brain's mesolimbic pathway.
[2] The model also considers these diseases as a result of other biological, psychological or sociological entities, despite an incomplete understanding of their mechanisms.
As noted by harm reduction specialist Andrew Tatarsky: The essence of this model is the pragmatic recognition that treatment must meet active substance users ‘‘where they are’’ in terms of their needs and personal goals.
Thus, harm reduction approaches embrace the full range of harm-reducing goals including, but not limited to, abstinence.