Although chemicals have long been used throughout history to alter cognition, mood, and behavior, the so-called “psychopharmaceutical era” originated in the late 19th and mid-20 centuries.
	The Food and Drug Administration is the U.S. governmental agency which approves and regulates medications.  Currently, there are more than 100 different pharmaceuticals which have received FDA “approval” for the treatment of psychiatric conditions.
	Excluding the chemicals which are specifically used to treat nicotine (varenicline), alcohol (disulfiram, acamprosate) and opioid dependence (naltrexone, methadone, buprenorphine), there are five major categories of psychotropic drugs:
	antidepressants
	antipsychotics   (sometimes called “major” tranquilizers)
	mood stabilizers   (anticonvulsants and lithium)
	sedatives/anxiolytics   (sometimes called “minor” tranquilizers)
	stimulants