The central nervous system (CNS) is composed of the brain and the spinal cord in humans. This is the primary processing system for the entire body. All other organ systems rely on this single system to govern and work the rest of the body. The peripheral nervous system works with the CNS to transmit messages to and from the other parts of the body.

The CNS is subject to a wide range of diseases, disorders, or injuries. These range from slight tremors diagnosed as essential tremor to more debilitating diseases such as multiple sclerosis. An also seemingly mild injury, such as a concussion, leads to debilitating conditions if the injury is repeated. Many times, different types of depressants and stimulants are prescribed by medical practitioners in ...