Psychopharmacology: Definition & History

Instructor: Gina Mitchell
The field of psychopharmacology helps us understand how prescription drugs, legal drugs, and illegal drugs change behavior in predictable ways. This lesson will give you an overview and history the field of psychopharmacology.

Psychopharmacology: Definition & History

Psychopharmacology is a combination of psychology, the scientific study of behavior, and pharmacology, the scientific study of drug action on biology. As a result, the primary goal of the field of psychopharmacology is to examine the effects of drug on behavior. The field examines how different drugs, man-made, naturally occurring, legal or illegal, change our biological responses and thus our behavior. Researchers looking at psychopharmacology might be interested in how different drugs change mood, sensations, cognition (our thoughts), or motor behaviors.


How Drugs Affect Behavior

In order for a drug to have an effect on behavior, it must have a target site within the body. Most drugs produce responses in the body by modifying the way that neurotransmitters work. Neurotransmitters are chemical messages that are sent in the nervous system. They allow for communication between cells of the nervous system. When their communication is altered, behavior changes. For example, when you use alcohol it causes changes within the neurotransmitter GABA. These changes then lead to altered behavior such as an increase in relaxation.

In examining drugs and their effects on behaviors, psychopharmacologists are most interested in two different principles about the drug. First, they want to look at the pharmacokinetics of the drug. This means that they examine how the drug is absorbed by the body, distributed throughout bodily systems, and how the body metabolizes and excretes the substance.

Secondly, researchers are concerned with pharmacodynamics, which is an examination of how the drug interacts with various neurotransmitters, receptors and other sites of action in the body. Examining these two areas allows scientists to see how the drug works and predict what effect the drug will have on behavior.

Individuals in the field of psychopharmacology have discovered that drugs can interact with neurotransmission in a number of ways. First a drug can act as an agonist, or it can act as a neurotransmitter. This is the case with heroin. Heroin has the same chemical shape as opioid neurotransmitters that are found in the body. Thus, when heroin is used it binds to opioid receptors in the body and produces changes in behavior including feelings of euphoria.

Another way that drugs can affect behavior is by blocking the receptor site. For example, certain antipsychotic drugs, block dopamine receptors to decrease the effects of dopamine at the receptor cites. These types of drugs are classified as antagonist drugs because the work in opposition to the neurotransmitter.

Other drugs affect neurotransmitters by altering their production, release or deactivation. Probably one of the most well known class of drugs are selective serotonin re-uptake inhibitors (SSRIs). These drugs work by inhibiting the re-uptake of serotonin. This process is an alteration of the deactivation of serotonin. As a result higher levels of serotonin are found in the body.


To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create An Account