How antidepressants treat depression

Regulating brain chemistry often plays a key role in treating major depressive disorder (MDD), or clinical depression. To understand how antidepressant medications reduce symptoms, it's important to know how the brain works to govern mood.

Basics of neurotransmitters

Brain cells (neurons) communicate with each other using chemicals called neurotransmitters, which they manufacture and release into the space between brain cells. Once the neurotransmitters are released, they are broken down by enzymes, get reabsorbed into neurons (reuptake), or connect with another neuron on a neurotransmitter receptor molecule.

When a neurotransmitter binds to a receptor molecule, it sets off a complex series of changes that can increase or reduce the chance that a brain cell will electrochemically fire. The firing of multiple brain cells in various areas of the brain affects what we experience as sensations, thoughts, and feelings—including feelings of depression.

Dozens of chemicals may serve as neurotransmitters. Many are involved in mood, including norepinephrine (NE), dopamine (DA), gamma-aminobutyric acid (GABA), and serotonin (5-HT). Depending on the neurotransmitter involved, they can excite, inhibit, or otherwise affect neurons.

Each neurotransmitter’s interaction with its potential receptor sites is extremely complex. This is why understanding how the brain works is so challenging and why it's a key area of research, with new chemical treatment approaches, including new antidepressant medications, emerging all the time to help treat clinical depression.

Neurotransmitters and antidepressants

Antidepressant medications work in several different ways, on different neurotransmitters, in different parts of the brain. This offers a variety of drug options to treat major depression.

Some commonly prescribed classes of antidepressants include:

• Serotonin norepinephrine reuptake inhibitors (SNRIs)
• Selective serotonin reuptake inhibitors (SSRIs)
• Monoamine oxidase inhibitors (MAOIs)

Your healthcare provider can discuss the specific benefits and potential side effects of each.