Atypical antidepressants are not typical — they don't fit into other classes of antidepressants. They are each unique medications that work in different ways from one another.
How atypical antidepressants work
Atypical antidepressants ease depression by affecting chemical messengers (neurotransmitters) used to communicate between brain cells. Like most antidepressants, atypical antidepressants work by changing the levels of one or more of these naturally occurring brain chemicals.
Atypical antidepressants affect neurotransmitters including dopamine, serotonin and norepinephrine. Changing the balance of these chemicals seems to help brain cells send and receive messages, which in turn boosts mood.
Atypical antidepressants approved to treat depression
The Food and Drug Administration (FDA) has approved these atypical antidepressants to treat depression:
Side effects of atypical antidepressants
Common side effects with most antidepressants, including atypical antidepressants, include dry mouth, constipation, and dizziness or lightheadedness. For antidepressants that cause sleepiness, be careful about doing activities that require you to be alert, such as driving a car, until you know how the medication will affect you. Because of the different way atypical antidepressants work, each also has unique characteristics and side effects.
Bupropion may be a good choice if you have low energy caused by depression or if you're trying to quit smoking. It's sometimes prescribed to ease nicotine cravings under the brand name Zyban. Bupropion doesn't cause sexual side effects or weight gain as several other antidepressants do, and it's sometimes prescribed to counter the sexual side effects of another antidepressant. However, bupropion can cause or worsen anxiety in some people. Additional side effects, among others, may include:
Mirtazapine is generally taken before bed because it can make you sleepy. Additional side effects, among others, may include:
Nefazodone may help ease anxiety as well as depression, but it can make you sleepy. It seems less likely to cause sexual side effects than do some other antidepressants. Additional side effects, among others, may include:
Trazodone causes sleepiness and can help with anxiety. Like mirtazapine, it's usually taken at bedtime. It may be prescribed alone or along with other antidepressants to help with sleep. Additional side effects, among others, may include:
Atypical antidepressants are safe for most people. However, in some circumstances they can cause problems. For example:
Other issues to discuss with your doctor before you take an atypical antidepressant include:
Suicide risk and antidepressants
Most antidepressants are generally safe, but the FDA requires that all antidepressants carry black box warnings, the strictest warnings for prescriptions. In some cases, children, teenagers and young adults under 25 may have an increase in suicidal thoughts or behavior when taking antidepressants, especially in the first few weeks after starting or when the dose is changed.
Anyone taking an antidepressant should be watched closely for worsening depression or unusual behavior. If you or someone you know has suicidal thoughts when taking an antidepressant, immediately contact your doctor or get emergency help.
Keep in mind that antidepressants are more likely to reduce suicide risk in the long run by improving mood.
Stopping treatment with atypical antidepressants
Atypical antidepressants aren't considered addictive. However, stopping antidepressant treatment abruptly or missing several doses may cause withdrawal-like symptoms. Symptoms will vary depending on how the drug works. This is sometimes called discontinuation syndrome. Work with your doctor to gradually decrease your dose.
Finding the right antidepressant
Each person reacts differently to a particular antidepressant and may be more susceptible to certain side effects. Because of this, one antidepressant may work better for you than another, or they may be used in combination. When choosing an antidepressant, your doctor will take into account your symptoms, your health problems, other medications you take, and what has worked for you in the past.
Inherited traits play a role in how antidepressants affect you. In some cases, where available, results of special blood tests may offer clues about how your body may respond to a particular antidepressant. The study of how genes affect a person's response to drugs is called pharmacogenomics. However, other variables besides genetics can affect your response to medication.
Typically it takes several weeks or longer before an antidepressant is fully effective and for initial side effects to ease up. You may need to try several antidepressants before you find the right one, but hang in there. With patience, you and your doctor can find a medication that works well for you.
Last Updated: 2013-06-25
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