Answer:
There are many kinds of appetite suppressants.
Acomplia (discontinued in the EU, maybe in the US also due to high risk of suicide) is contradicted officially to psychiatric disorders (for which you are taking the SSRIs) but if your psychiatrist prescribed it so, it's ok.
Meridia/Reductil is itself an SSRI, so co-administration is not a great idea. Discontinued in many countries due to risk of suicide.
Most probably you are referring to Ampetamine class, stick to doctors instructions. It is possible, but co-administration may have some risks.