Regarding psychotropic drugs, which of the following statements is FALSE?

Regarding psychotropic drugs, which of the following statements is FALSE?
 
  a. Scientists have developed drugs that work on neurotransmitter irregularities that are involved in a wide range of psychological disorders.
  b. There are four major groupings of psychotropic drugsantianxiety, antidepressant, antipsychotic, andantisomatic.
 c. Psychotropic drugs work as either agonists or antagonists.
  d. Limitations of psychotropic drugs include side effects and potential for abuse.
  e. Compared to other biomedical therapies, psychotropic drugs are less controversial.