Because they are easier to obtain (i.e. you don't need a script from the doctor to get them, you can go and buy them freely) and in some cases can give you the same high as street and prescription drugs
I used to get those all the time and my parents just tell me to lay on the side that hurts. Or you can just roll your neck all around.
Obsessive–compulsive disorder (OCD) is amental disorder where people feel the need to check things repeatedly, perform certain routines repeatedly (called "rituals"), or havecertain thoughts repeatedly. People are unable to control either the thoughts or the activities for more than a short period of time.
