You should not discontinue medication until you speak with your healthcare provider.
Neuroanatomy and neurochemistry are complex systems. A high level symptom like depression could be coming from any one of a myriad of causes. A given medication works against specific causes, but will not work if your symptoms are being caused by something not targeted by that medication.
Until our technology and understand improves to the point that we can do some kind of neuroimaging to diagnose, the only thing we can do is to listen to your symptoms and make a best guess. If it doesn’t work, it means that guess was wrong, and you either need a dosage adjustment or a medication change. If it does work but has unmanageable side effects, that’s the same. Any continuing symptoms or side effects have diagnostic relevance, and you need to work with medical staff to dial it in.