Antidepressants: Selecting one that's right for you

Medication is often the first treatment choice for adults with moderate or severe depression. Although antidepressant medications don't cure depression, they can help you achieve remission — the disappearance or nearly complete reduction of symptoms. Sadness, anxiety, depression-related sleep and appetite problems, concentration, and energy levels all can improve with antidepressant medications.

For many people, combining medication use with psychotherapy, such as cognitive-behavioral therapy, proves most effective. With scores of antidepressants available, though, finding the right one for your situation can be challenging. Understanding what a treatment plan entails and what goes into determining the right medication for you will help you sort through your options.

How antidepressants work

Precisely how antidepressants work to treat depression remains speculative. Scientists do know that antidepressants can influence brain activity through the effects they have on mood-related brain chemicals called neurotransmitters and certain nerve cell receptors. Nerve cells release neurotransmitters to communicate with other nerve cells in the brain. Neurotransmitters transmit signals across a gap (synapse) between the nerve cells.

Neurotransmitters associated with depression are serotonin (ser-oh-TOE-nin), norepinephrine (nor-ep-ih-NEF-rin) and possibly dopamine (DOE-puh-mene). Research suggests that people with depression have lower levels of one or more of these neurotransmitters.

Nerve cells send a signal and then reabsorb (reuptake) the neurotransmitters after they've communicated with other nerve cells. Antidepressants interfere with this reuptake. This results in a greater quantity of a particular neurotransmitter remaining in the synapse. This can change the activity of certain nerve cells and influence brain activity. Maintaining a higher level of neurotransmitters improves neurotransmission — the sending of those nerve impulses — which, in turn, improves your mood.

In addition, a type of antidepressant called alpha-2 receptor blockers is thought to work by preventing neurotransmitters from binding with the nerve cell receptors called alpha-2 receptors. This indirectly increases the levels of norepinephrine and serotonin in your brain.

Numerous types of antidepressants available

Dozens of antidepressants are available, each affecting neurotransmitters in a different way. Antidepressants are typically grouped into categories, either based on when the medications came into use, their chemical structure or how they affect brain chemistry.

Here are the antidepressants that have been approved by the Food and Drug Administration (FDA) specifically to treat depression, with their generic names followed by available brand names in parentheses, and grouped by how they affect brain chemistry.

Selective serotonin reuptake inhibitors (SSRIs)

• Citalopram (Celexa)
• Escitalopram (Lexapro)
• Fluoxetine (Prozac, Prozac Weekly)
• Paroxetine (Paxil, Paxil CR)
• Sertraline (Zoloft)

Off-label use of drugs

The FDA normally approves a drug to treat a specific condition in a particular population. Many drugs used to treat depression in adults have been FDA approved specifically for that use.

But doctors may also prescribe drugs to treat depression that haven't actually been approved to treat depression — a practice known as off-label use. For instance, doctors often prescribe clomipramine (Anafranil) because it may improve depression even though it's FDA approved for obsessive-compulsive disorder. The same may be true of other psychiatric drugs, as well.

Finding the right medication for you

So among the dozens available, which antidepressant should you take?

Finding the right one might take time. Each medication has its own pros and cons, and until you try one, you won't know how it'll affect you or how well it'll work. You may need to try several antidepressants before finding the one, or the combination, that's most effective for you with the fewest side effects.

Consider your health profile
Your family doctor or psychiatrist will take into account your symptoms and their severity, your health history, other illnesses you have and lifestyle factors when determining which antidepressant to prescribe.

Your doctor will also consider your age, sex, weight and diet, mostly because of concerns about side effects. Older adults, for instance, generally tolerate the side effects of the newer antidepressants better than the side effects of the older tricyclic antidepressants. However, for some people, the older medications are more effective in treating depression.

Pregnancy is also an issue. Some psychiatric medications may pose a risk to the developing baby. Other medications may be excreted in breast milk to infants.

If any close relatives, such as a brother or sister, have taken antidepressants, their experiences could predict how well a medication will work for you or what side effects you may experience. Tell your doctor if any of your close relatives have taken antidepressants.

Make your personal preferences known
How you take an antidepressant may also influence your medication choice. Some medications come in pill form, while others come as solutions or injections. You may not be comfortable taking an antidepressant that must be injected, for instance. Or you may prefer a once-a-week medication, while someone else doesn't mind taking several doses a day.

Cost is also a consideration. Some antidepressants are available in a generic form, which is generally cheaper than a brand-name version. Newer versions of a drug are sometimes more expensive than the original. But watch out — those newer versions aren't necessarily more effective.

Trying the medications

Once you and your doctor have selected an antidepressant for you to try, it may take four to eight weeks to determine its full effectiveness. With some medications, you can take the full dosage immediately. With others, you may need to gradually increase your dose.

If you have no improvement at all in your symptoms after six weeks, it may be time to try a different antidepressant or add a second medication to augment your treatment. You may have to taper off of one medication before starting another, because potentially dangerous drug interactions and withdrawal-like symptoms can occur from an abrupt switch.

In rare cases, antidepressants simply might not work for you. You may need to consider other forms of treatment, such as psychotherapy to help cope with social or other life stressors, or electroconvulsive therapy if your depression is severe or life-threatening.

Common side effects of antidepressants

All antidepressants cause some degree of side effects. Most side effects are mild and temporary. In general, the most common are:

• Nausea
• Sexual dysfunction
• Constipation
• Bladder problems
• Dizziness
• Drowsiness
• Dry mouth
• Changes in sleep patterns
• Restlessness

Side effects vary by medication and by person. Your side effects might be more severe or less severe than what someone else taking the same medication experiences.

New cautions about suicidal thoughts

In some cases, antidepressants may be associated with worsening symptoms of depression or suicidal thoughts or behavior, particularly early in treatment or when you change your dosage.

In October 2004, the FDA began requiring that all antidepressants carry a "black box" warning — the strongest warning it can issue — alerting doctors and the public to a link between antidepressants and suicidal thoughts and behavior in children and adolescents. Each prescription must also provide a medication guide that advises parents and caregivers about risks and precautions.

Length of treatment varies by situation

How long will you have to take antidepressants? It can range from several months to a lifetime.

Treatment of depression with medications is often divided into two stages. The initial focus on getting better is called acute therapy. Later, the focus turns to staying well, called maintenance or continuation therapy. In general, your doctor will probably suggest that you continue taking antidepressants for at least six months — and more likely 12 months — even after remission of your symptoms and you feel better. This will help prevent a return of your symptoms.

If your depression is chronic or recurrent, you'll probably have to take medication for years or even for the rest of your life to help control your symptoms and prevent a relapse.

Deciding how long to continue medication treatment includes consideration of:

• The length and severity of your depression before treatment started
• How difficult the depression was to treat
• Whether you've previously had depression
• Your family's history of depression
• Your stress levels before, during and after treatment

Don't stop taking a medication without consulting your doctor even if you're feeling better. Stopping a medication too soon can make you more vulnerable to a relapse. It can also cause withdrawal-like symptoms if done suddenly.

If you do stop a medication and your symptoms return, talk to your doctor about starting medication again. But be aware that in some cases, if you stop a medication and then restart it, it may no longer be effective.

Although the choices may seem daunting, with some persistence, you have a good chance of finding an antidepressant that works well for you and that has only mild side effects that won't disrupt your lifestyle. The payoff is your ability to enjoy life more fully again.