A class of antidepressants called selective serotonin re-uptake inhibitors (SSRIs) are the most commonly prescribed medication for depression today. Prozac (fluoxetine), Paxil (paroxetine), Zoloft (sertraline) and Luvox (fluvoxamine) are the most commonly prescribed brand names. SSRI medications should not be prescribed in conjunction with the older MAOIs (more popular in Europe than in the U.S.). SSRIs work on increasing the amount of serotonin in the brain. Researchers are not sure why an increase in serotonin helps relieve depression (there’s little evidence of support for the serotonin theory of depression), but decades’ worth of studies suggest such medications nonetheless help improve mood.
SSRI antidepressant medications were once thought to have lesser side effects than other antidepressants, but research in the past decade suggests differently. While SSRI antidepressants appear to be safe, most people will experience side effects while taking them, such as nausea, diarrhea, agitation, insomnia, or headache. For most people, these initial side effects will go away within 3 to 4 weeks.
Many people taking an SSRI complain of sexual side effects, such as decreased sexual desire (decreased libido), delayed orgasm, or an inability to have an orgasm. Some people also experience tremors with SSRIs. Serotonin syndrome is a rare but serious neurological condition associated with the use of SSRIs. It is characterized by high fevers, seizures, and heart-rhythm disturbances.
Long-term side effects of taking SSRI medications for more than a year include sleep disturbance, sexual dysfunction, and weight gain.
Depression treatment takes time and patience is needed. The large-scale, multi-clinic government research study called STAR*D found that people with depression and who take a medication often need to try different brands and be patient before they find one that works for them. The effects of medications will usually be felt within 6 to 8 weeks of taking an antidepressant, but not everyone feels better on the first medication tried. You may have to try 2 or 3 different medications before finding the one that works for you.
Results from one of the findings of the study apply to those who do not get better after two medication treatment steps. At this stage, by switching to a different antidepressant medication, about one in seven people will get better and by adding a new medication to the existing one, about one in five people will get better. Finally, for patients with the most treatment-resistant depression, additional results suggest that tranylcypromine is limited in its tolerability and that up to 10 percent may benefit from the combination of venlafaxine-XR/mirtazapine.
An overall analysis of the STAR*D results indicates that patients with difficult-to-treat depression can get well after trying several treatment strategies, but the odds of beating the depression diminish with every additional treatment strategy needed. In addition, those who become symptom-free have a better chance of remaining well than those who experience only symptom improvement. And those who need to undergo several treatment steps before they become symptom-free are more likely to relapse during the follow-up period. Those who required more treatment levels tended to have more severe depressive symptoms and more co-existing psychiatric and general medical problems at the beginning of the study than those who became well after just one treatment level.
Other medications may also be of help. Atypical antidepressants are often prescribed when a person hasn’t improved with a common SSRI. Such medications include nefazodone (Serzone), trazodone (Desyrel), and bupropion (Wellbutrin). Abilify (aripiprazole) is also an aytpical antipsychotic that is approved for the use in the treatment of depression. It is the first medication approved by the U.S. Food and Drug Administration for “add-on treatment.” That is, your doctor can prescribe it to you even if you’re already taking an antidepressant. In clinical studies, when Abilify was added to an antidepressant treatment, many people experienced significant improvement of their depressive symptoms.