Is there any correlation between the mother taking depression drugs and autism?
Not that I know of.
I have not looked at the studies supporting the FDA approval of the various depression drugs, so I do not know whether they have been tested in pregnant subjects (even pregnant rats).
In an intuitive way, it would make sense that these drugs could have an effect on the developing brain. They certainly have the ability to penetrate the blood-brain barrier. But whether they would interact with growth factors or DNA or some other physiological component that would affect brain growth--I just do not know.
I do know, however, that autism existed long before any psychoactive drugs were invented.