The major classes of antidepressant medication are the selective serotonin re-uptake inhibitors (SSRIs), the tricyclic antidepressants (TCAs), the monoamine oxidase inhibitors (MAOIs), and the atypical antidepressants.

SSRI medications affect levels of serotonin in the brain. For many people, these medications are the first choice. Examples of these medications are listed here. The generic name is first, with the brand name in parentheses. These drugs are best known by their brand names.

• Fluoxetine (Prozac)
• Sertraline (Zoloft)
• Paroxetine (Paxil)
• Fluvoxamine (Luvox)
• Citalopram (Celexa)
• Escitalopram (Lexapro)

TCAs are often prescribed in severe cases of depression or when SSRI medications don’t work. Like the SSRIs, most of these are better known by their brand names.

• Amitriptyline (Elavil)
• Clomipramine (Anafranil)
• Desipramine (Norpramin)
• Doxepin (Adapin)
• Imipramine (Tofranil)
• Nortriptyline (Pamelor)
• Protriptyline (Vivactil)
• Trimipramine (Surmontil)

The MAOIs are not used as often since the introduction of the SSRIs. Because of interactions, the MAOIs may not be taken with many other types of medicines, and some types of foods that are high in tyramine (like aged cheeses, wines, and cured meats) must be avoided as well.

• Phenelzine (Nardil)
• Tranylcypromine (Parnate)

The atypical antidepressant medications work differently than the commonly used SSRIs. These medications may be prescribed when SSRIs have not worked.

• Bupropion (Wellbutrin)
• Mirtazapine (Remeron)
• Nefazodone (Serzone)
• Trazodone (Desyrel)
• Venlafaxine (Effexor)

One-half to two-thirds of people who take antidepressant medications get better.

• It may take anywhere from one to six weeks to start feeling better. Don’t give up taking the medication if you don’t feel better right away.
• Your health-care provider will see you again during this period to see if your body is tolerating the medication and if your symptoms are better. If they are not, he or she may adjust your dose or prescribe a different medication.

Even after you feel better, you should continue to take the medication for six to nine months.

• Stopping the medication too soon may cause your symptoms to return, or to get worse.
• Some people need to take the medication for longer periods of time to keep the depression from returning.

Do not stop taking the medication without talking to your health-care provider.

• Stopping abruptly may cause serious withdrawal effects.
• If you and your health-care provider agree it is time to stop the medication, the dose usually will be slowly tapered to prevent these effects.

The side effects of antidepressant medications vary considerably from drug to drug and from person to person.

• Common side effects include dry mouth, sexual dysfunction, nausea, tremor, insomnia, blurred vision, constipation, and dizziness.
• You may need to follow some dietary restrictions if you are taking MAOI medications.
• In very rare cases, some patients have been thought to have become acutely more depressed once on the medication, even attempting or completing suicide or homicide. Children and teenagers are thought to be particularly vulnerable to this rare possibility.
• If an antidepressant medication is prescribed for you, ask your health-care provider what kind of side effects you can expect.