Memory disturbance of ECT recovers in -
Amnesia after ECT is almost always reversible within few weeks to 2 months.

Remember

Amnesia for the memory of 6 months before ECT → Retrograde amnesia for 6 months.
Amnesia for 2 months after ECT → Antegrade amnesia for 2 months.
Few days to few weeks
Few weeks to few months
Few months to few year
Permanent