Antidepressant Side Effects: What You Need to Know Before You Start

When you start an antidepressant, a medication prescribed to treat depression, anxiety, and sometimes chronic pain or insomnia. Also known as SSRIs, SNRIs, or TCAs, it can change how your brain chemistry works—but it doesn’t always feel like an improvement at first. Many people stop taking them within the first few weeks because of side effects. Not because the drug isn’t working, but because the initial discomfort feels worse than the depression itself.

Antidepressant side effects, unwanted physical or mental reactions that happen after starting the medication are real, predictable, and often temporary. Nausea, drowsiness, dry mouth, weight gain, and sexual dysfunction are among the most common. For some, these fade after 2–4 weeks as the body adjusts. But for others, they stick around—and that’s when you need to talk to your doctor. Not to quit, but to switch, adjust, or add something that helps. Medication adherence, the act of taking your drug exactly as prescribed isn’t about willpower. It’s about matching the right drug to your body, not forcing your body to fit the drug.

Some side effects are warning signs. If you feel worse after starting an antidepressant—more anxious, agitated, or having thoughts of self-harm—don’t wait. Call your provider. These aren’t normal adjustments. They’re red flags. And if you’ve been on an antidepressant for months or years, suddenly stopping can cause antidepressant withdrawal, a set of physical and emotional symptoms that occur when you stop the drug too quickly. Dizziness, brain zaps, flu-like symptoms, and mood swings can follow. Tapering off slowly, under supervision, makes all the difference.

You’re not alone in this. Nearly half of people on antidepressants experience side effects that make them question whether the trade-off is worth it. But the goal isn’t to feel perfect—it’s to feel better than you did before. Some people find relief with a different pill. Others need therapy, lifestyle changes, or a combination. The key is staying in the conversation with your doctor, not dropping out because the first version didn’t feel right.

Below, you’ll find real stories and science-backed advice on how to handle the tough first weeks, what side effects to ignore versus what to act on, how to talk to your doctor without sounding like you’re giving up, and what alternatives exist when one drug just doesn’t fit. These aren’t theoretical tips. They’re from people who’ve been there—and lived to tell the story.