Understanding Antidepressants (SSRIs & SNRIs)

What are SSRIs and SNRIs?

Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) are the most commonly prescribed antidepressant medications, used for depression, anxiety disorders, OCD, and panic disorder. They work by increasing the availability of serotonin (and, for SNRIs, norepinephrine) in the brain, which helps regulate mood over time.

What to expect

• Full effect usually takes 4-6 weeks, though some improvement in sleep or anxiety may be noticed earlier
• An initial period of mild side effects (nausea, jitteriness, headache) often settles within 1-2 weeks
• Your psychiatrist may adjust the dose based on your response and side effects
• Treatment is usually continued for 6-12 months after symptoms improve, to reduce relapse risk

Common side effects

• Nausea or stomach upset, usually early and temporary
• Headache or mild dizziness
• Sleep changes — some antidepressants are more activating, others more sedating
• Reduced sexual interest or response, which can persist and should be discussed with your psychiatrist
• Mild weight change over time

Important safety notes

• Do not stop abruptly — stopping suddenly can cause discontinuation symptoms (dizziness, flu-like feelings, irritability); doses should be tapered under medical guidance
• Tell your psychiatrist about all other medications and supplements, since some combinations increase serotonin syndrome risk
• Report any new or worsening suicidal thoughts immediately, especially in the first few weeks or after a dose change
• Avoid combining with alcohol or recreational drugs without discussing this with your psychiatrist