There are five major classes of antidepressants, each with unique properties and intended uses.
Class 1 antidepressants are the most commonly prescribed antidepressants and work by increasing serotonin levels in the brain. They are usually effective in the short-term treatment of depression, but they may also have side effects, including headaches, nausea, and dizziness.
Class 2 antidepressants work by blocking the reabsorption of serotonin in the brain. They are more effective than class 1 antidepressants but can also have more side effects, including decreased appetite, insomnia, and weight gain.
Class 3 antidepressants are the newest type of antidepressant and are thought to work by modifying how the brain processes serotonin. They can be more effective than class 2 antidepressants but may also have more side effects, including sexual side effects and increased risk of suicidal thoughts and behavior.
Class 4 antidepressants are the least commonly prescribed antidepressants and are thought to work by altering how the brain processes norepinephrine. They can be more effective than class 3 antidepressants but may also have more side effects, including increased risk of suicidal thoughts and behavior and decreased libido.
Class 5 antidepressants are the oldest type of antidepressant and are thought to work by altering how the brain processes serotonin, norepinephrine, or both. They can be more effective than class 4 antidepressants but may also have more side effects, including decreased appetite, insomnia, and weight gain.
