Today You Can advocates the disease model of addiction. According to MentalHelp.net, The disease and biological theories of addiction are very similar. However, the disease model of addiction highlights the differences between people with the disease and those without it. In contrast, the biological model focuses on the genetic risk for developing the “disease” of addiction. According to the disease model, addiction is a brain disease. It is characterized by altered brain structure and functioning. These brain abnormalities cause persons with this disease to become addicted to substances or activities, once exposure to these substances or activities occurs. This model considers addiction irreversible once acquired.
I hope this helped you understand if addiction is a disease.