Never used drugs or alcohol. but if it was a psychosis episode as well (doc didn't say) , will lexapro (escitalopram) help steer that away?

Not by itself: Lexapro (escitalopram) alone will not steer away a psychotic episode. You might know if you were hallucinating or delusional at the time -- you might be very suspicious of others' motives, hearing voices, etc, you might also ask a close friend or family member who was with you during the episode, about your behavior if you don't remember it. Also you can ask your doctor, of course!

Not usually: Lexapro (escitalopram) is an anti depressant/anti anxiety medication. It is not generally used as an anti psychotic treatment. Speak to your doctor about other alternatives.