SSRIs and Depression: How Do They Work?

By: Dr. Chelsea Slyker, PharmD, MPH

Depression is a mood disorder that can result in long-term feelings of sadness and a loss of interest in normal activities. To be clinically diagnosed with depression, symptoms must last for at least 2 weeks and affect your daily activities. Depression can result in weight loss, thoughts of death or suicide, decreased energy, and difficulty sleeping. While the exact cause of depression is unknown, there are a number of different treatments to help control your mood and stress levels. Selective serotonin reuptake inhibitors (SSRIs) are a common treatment for depression and can provide a number of benefits to those suffering.

SSRIs are the most commonly prescribed class among antidepressants and include drugs such as escitalopram (Lexapro), fluoxetine (Prozac), and sertraline (Zoloft).

They work by preventing the reuptake of the neurotransmitter serotonin, making more available in your brain and helping to control symptoms of depression. Because of the mechanism of the medication it can take 2-4 weeks to see some symptom improvement and up to 8 weeks to see the full benefit.

SSRIs and Depression

SSRIs are typically well tolerated but may have a few side effects.

Common side effects include nausea, drowsiness, dry mouth, insomnia, diarrhea, and sexual problems. Some of these can be managed by how and when you take the medication, such as with food if it causes nausea or at night if it causes drowsiness. If side effects on one SSRI are not manageable, your doctor can help you change your dose or choose another option. You should try at least 2 different SSRIs before switching to a different class.

SSRIs can cause withdrawal symptoms if a dose is missed, so good adherence is important. While withdrawal symptoms are not life threatening, they can be unpleasant and should always be avoided if possible. They can also interact with other medications, so be sure to tell your provider what you are currently taking. Talk to your doctor about any concerns you have about SSRIs and/or your depression.

For more information on depression, visit: https://www.nimh.nih.gov/health/topics/depression/index.shtml