According to an article in Medscape Psychiatry today there is a new and better system to classify psychotropic medicine. It uses a system of 4 different point. In the first point there is a description of biological target of the drug and the way it works. The second point would contain the reason the medication is used. The third point is the effectiveness and side effects while the fourth point is a description of the biology of the medicine in the brain. 

For example, take a drug like Celexa. Using the system it would be described as possible.

1) Targets Serotonin – making it more available in between nerve cells.

2) Treatment of Major Depressive Disorder (the reason for its use).

3) Generally improves symptoms of depression. Can cause drowsiness.

4) Works on neurotransmitters, the chemicals that help transit information from one neuron to another neuron.