Can Zoloft (sertraline) affect your memory? I've been taking 100mg and I just seem to be very forgetful.

Maybe. Forgetfulness is also part of depression, . While it could be a medication side effect , I wonder how long you have been taking it at this dosage. You could still be experiencing distraction and forgetfulness related to your depression, or even breakthrough depression. If your mood is ok, it is probably medication related which can happen with SSRI's as other docs have said.
Yes . Zoloft (sertraline) works on the central nervous system and it stands to reason that it can cause some sedation snd forgetfulness if taken in the AM . It seems that the effect of forgetfulness and sedation maybe dose related . I prescribe it to be taken at night where the sedation side effects are less in the morning . . .