Antidepressants: What to Know Before You Start

Antidepressants help many people feel better, but they work differently and come with trade-offs. If you or someone you care about is thinking about medication, this page lays out the basics in plain language—how the main types work, what side effects to expect, and simple safety steps you can use right away.

Types and how they work

Most antidepressants fit into a few groups. SSRIs (like sertraline or fluoxetine) increase serotonin and are usually first-line because they’re easier to tolerate. SNRIs (venlafaxine, duloxetine) boost serotonin and norepinephrine and can help pain as well as mood. Tricyclics and MAOIs are older drugs that still work for some people but need more monitoring. Then there are atypical antidepressants (bupropion, mirtazapine) that target other brain chemicals. Expect 4–6 weeks to notice real change; early effects (sleep, appetite) may show up sooner.

Side effects vary by drug: nausea, sleep changes, and sexual side effects are common with SSRIs. Bupropion is less likely to cause sexual problems but can raise anxiety or risk of seizures in certain cases. Weight gain shows up with some meds like mirtazapine. If side effects start, don’t stop abruptly—talk to your prescriber about dose changes or switching drugs.

Practical safety tips and when to call for help

Start low and go slow. Keep a short symptom diary for the first 8 weeks—note mood, sleep, appetite, and any odd thoughts. If you’re under 25, the risk of suicidal thoughts can briefly rise when a medicine first starts; check in with your prescriber and someone you trust. If you have heart disease, seizures, or are pregnant, say so—some antidepressants need caution.

Watch drug interactions. Don’t mix MAOIs with SSRIs or certain migraine drugs—this can cause serotonin syndrome (high heart rate, fever, confusion). St. John’s Wort can make SSRIs unsafe. Ask your pharmacist about interactions with blood thinners, heart meds, or over-the-counter supplements. If you buy meds online, stick to reputable pharmacies and keep prescriptions; our site covers safe pharmacy tips if you need guidance.

Stopping medication often causes withdrawal-like symptoms: dizziness, flu-like feelings, irritability, or return of mood symptoms. Taper gradually under medical supervision. Combine medication with therapy—CBT and regular exercise show strong, reliable benefits, especially for mild to moderate depression. Small lifestyle steps like consistent sleep, sunlight, and movement make a real difference alongside meds.

If you’re unsure what’s right, ask for a clear plan: expected timeline, how side effects will be managed, and a follow-up in 2–4 weeks. Good care is teamwork—you, your prescriber, and your pharmacist. Want more specific reads? We have guides on related meds, interactions, and safe online pharmacies to help you make informed choices.