Long-term use of opioids can be dangerous. It can cause changes to the brain that affect your mood, impulse control, motivation, and feelings of reward or pleasure. 

Over time, the opioid receptors in the brain change. They need more and more opioids to achieve the same effect. The opioid receptors become dependent on the drug to function correctly. If you stop taking the drug, you may become physically sick, also known as withdrawal.