Dissociating while driving, ending up somewhere unfamiliar... no recollection?

I started taking Lexapro recently for depression. Since starting it, this weird thing has happened twice. I'll get in the car on my way to go grocery shopping or to school, and I'll end up somewhere completely different. I have no recollection of driving there, how I got there, nothing. I just snap out of it and I say to myself "where the hell am i?". I told my therapist this and she told me that I was most likely dissociating and that I should go to the doctor to see if it was the medication. He told me to stay on it and referred me to a psychiatrist... and sent a social worker into the room to talk to me about abuse and my life, and it was very uncomfortable. But anyways, could this be from the medication, or is it just a symptom that just started due to depression?