Antidepressant Fatigue: Why It Happens and What You Can Do

When you start taking an antidepressant, a medication prescribed to treat depression and some anxiety disorders by balancing brain chemicals. Also known as antidepressant medication, it helps millions feel like themselves again. But for many, the relief comes with a heavy cost: persistent tiredness that doesn’t go away. This isn’t just regular exhaustion. It’s antidepressant fatigue, a side effect where energy levels drop significantly after starting or adjusting antidepressant treatment. It’s not laziness. It’s not your fault. And it’s not always temporary.

Most SSRIs, a class of antidepressants that increase serotonin levels in the brain. Also known as selective serotonin reuptake inhibitors, they like sertraline or fluoxetine, and SNRIs, a group of antidepressants that affect both serotonin and norepinephrine. Also known as serotonin-norepinephrine reuptake inhibitors, they like venlafaxine, can cause this kind of fatigue. Why? Because they change how your brain handles energy signals. Some people feel foggy, sluggish, or like they’re moving through syrup—even if their mood improves. It’s not the depression coming back. It’s the medicine itself wearing you down.

What makes it worse is that doctors rarely warn you about this. Many assume fatigue means the depression isn’t fully treated. But if you’re sleeping well, eating okay, and still feel drained, it’s likely the drug. The good news? This isn’t permanent for everyone. Some people adjust in 3–6 weeks. Others need a switch. There’s no one-size-fits-all fix. Some find relief by lowering the dose, switching to a different antidepressant, or adding a small stimulant under medical supervision. A few even report better energy after switching from an SSRI to bupropion, which is less likely to cause tiredness.

And it’s not just about pills. Fatigue from antidepressants can mix with sleep problems, low vitamin D, thyroid issues, or even stress from managing a chronic condition. That’s why so many people end up trying alternatives—like therapy, exercise, or even light therapy—to help balance things out without adding more meds. The posts below show real comparisons between antidepressants, what users actually experienced, and how others managed the fatigue without quitting treatment entirely. You’re not alone in this. And there are options.