Narcotic drugs
Narcotic drugs used to destroy many lives. It has many disadvantages. People who drug narcotic too much have symptoms of the nervous system. Someone see illusion, say alone or be crazy. And they are very addictive. For example several people addicted to coffee that consist of a few narcotic drug.
In the other hand, in medical, narcotic drugs can cure some symptom too such as doctor can use them to ease your pain after surgery, give opiates to women during early the stage of labor in order to relieve women’s pain etc.