Origin: Greek prefix anti-
Antidepressant has 3 different meanings across 1 category:
any of a class of drugs used to treat depression; often have undesirable side effects
"After taking his antidepressant for weeks, he finally felt less sadness but had to quit because the drug caused severe nausea and dizziness."
An agent that prevents or counteracts depression.
"After weeks of feeling hopeless, she finally started taking her new antidepressant and began to see a glimmer of joy return to her days."
Preventing or counteracting depression.
"After weeks of feeling overwhelmed and hopeless, Sarah finally started taking her new antidepressant to help prevent a full-blown episode of depression."