Some do become ineffective. Then the doctor will usually up the dosage of them until it's at the maximum dosage. If that becomes ineffective they'll change it to something else. I've been on the max of Paxil for a couple of years now and it still seems to be working. I take Abilify with it but I'm not at the maximum dosage of that yet.

I am currently taking Prozac it helps. In the past I have stop taking my depression meds because I felt better. Unfortunately this did not last to long. So yes it is true that once your body gets used to a medication the dosage would have to be increased. Which is why they do blood test to determine if the level needs to be changed.

Over a period of time even if meds are changed...side-effects can be too difficult to deal with...eventually
side-effects add to suffering and in the long run...despite the meds being changed...there's the limit that's reached and meds become ineffective

I’ve been on all different kinds of meds for 30 years now . Sometimes they do “ Peter out “
I was on just Prozac for 10 years and worked great but the last 20 years hv been hit or miss . I wish u luck In finding something that works for you

I have been on antidepressants before and I have had the experience of becoming amune to them and that causes them not to work properly. Once I feel like they stop working I always end up back at the dr to get prescribed a new medicine until my body gets used to it then back again for something new.