Addictive behaviors worsen overtime for many different reasons. Some people experience co-occurring disorders in which treating the addiction is not treating the root cause. Addiction changes the structure of the brain overtime so in many cases it only gets worse. Another reason that addictive behaviors worsen overtime is because of tolerance and the lifestyle that is involved such as stealing and lying.
Addiction in general is extremely difficult to treat and many people are resistant to treatment. My first example was about people who experience other mental health disorders at the same time as their addiction therefore, these individuals may be okay with treatment as a short term option but long term, if the other disorders are not treated then their addiction will likely return. Next, addiction, especially drug addiction, changes the structure of the brain so oftentimes; people will not be able to cognitively make good decisions especially in regards to treatment which may cause resistance. Lastly, people who develop a high tolerance will likely get mingled into the lifestyle that accompanies addiction. This is likely to involve legal situation. Many people who suffer from addiction are forced to get treatment to avoid jail time. These individuals may still be in denial and will resist treatment.