The medications used to treat depression are called antidepressants. The commonly used antidepressants are selective 5-hydroxytryptamine reuptake inhibitors (SSRIs), including Prozac (fluoxetine), paroxetine (paroxetine), Zoloft (sertraline), and Lanxess (fluvoxamine). SSRIs increase the amount of 5-hydroxytryptamine in the brain, and the increase in 5-hydroxytryptamine helps relieve depression. Medications prescribed by an internist or psychiatrist are generally safe and effective, but it is important to remember that SSRI medications should not be used at the same time as monoamine oxidase inhibitors. SSRI antidepressants have fewer side effects than other antidepressants, but taking SSRI antidepressants can also cause side effects such as nausea, diarrhea, moodiness, insomnia and dreaminess, and headaches, most of which disappear after 3 to 4 weeks of treatment. The most serious side effect of SSRIs is 5-hydroxytryptamine syndrome, but it is very rare, mainly manifesting as high fever, convulsions, and heart rhythm disturbances. Common side effects of SSRI drugs taken continuously for more than a year are sleep disturbances, sexual dysfunction and weight gain. Treatment of depression requires time and patience. The STAR* D, a large sample of U.S. multicenter clinical studies, found that antidepressants take 6-8 weeks to work, but not all people are effective on the first antidepressant, and depressed patients usually need to switch to 2-3 medications before they finally work. results from the STAR* D study showed that if treatment with the first SSRI did not work, a quarter of people would get better after switching to another one. If another antidepressant is added to the existing medication one third of the people get better. If the second medication is a different type of medication, such as bupropion for patients taking an SSRI, or if an SSRI is added to an SSRI to enhance the pharmacological effects of the SSRI, such as bupropion, the outcome is even better. In addition, the combination of venlafaxine extended-release and mirtazapine was 10% effective in treating patients with refractory depression. STAR* D results suggest that refractory depression can mostly improve after several systematic adjustments of the treatment regimen. However, effectiveness decreases with increasing dosing regimens. Patients with complete symptom remission had good long-term outcomes, while those with residual symptoms had much poorer long-term outcomes. Patients with multiple treatment regimens that are effective are prone to relapse; those with severe symptoms, psychiatric symptoms, and physical illness usually require multiple treatment regimen changes to be effective. If these approaches are not effective, other medications may be considered. Atypical antidepressants, such as nefazodone, trazodone, and bupropion, may be tried if SSRIs are ineffective. Aripiprazole is an atypical antipsychotic that is also approved for the treatment of depression. This means that your doctor may also prescribe you some atypical antipsychotics to assist in your treatment when you are not doing well with antidepressants. This article is not intended to be a specific treatment plan for any individual, and individualized treatment will have to be done in consultation with your doctor.