Did my Doctor give me a placebo?

I’ve been avoiding my counselor and school psychologist for a long time and they’ve practically forgotten about me because I thought I could get better myself and not believe I had depression but recently it’s gotten a whole lot worse and when I finally had rational thinking I quickly made an appointment to my Doctor.

I talked to him about what was going on and he suggested I take Lexapro(escitalopram).
But the thing is, I didn’t have to pay for it and he just happened to have it in stock at the time and gave it to me. I didn’t question it at the time but now I’m just confused. Don’t we normally get a prescription and have to go see a chemist?