Doctors don't fully understand what causes the so-called "poop-out" effect or antidepressant tolerance — known as tachyphylaxis — or why it occurs in some people and not in others. There also can be other reasons an antidepressant is no longer working for you, such as: Worsening depression. read more
Even just a single dose of an antidepressant can cause these changes and trigger withdrawal after discontinuing or reducing the dose. Some people do experience tolerance from taking antidepressants, and it can occur from any class of antidepressant. read more
There also can be other reasons an antidepressant is no longer working for you, such as: Worsening depression. It's common for depression symptoms to return or worsen at some point, despite treatment. Called breakthrough depression, symptoms may be triggered by stress or appear with no apparent cause. read more