For most people, the side effects of antidepressants start right away but the positive effects you're looking for usually take 4-6 weeks to notice. Now, the truth about these meds is, everyone has their own experience, and you might very well notice positive effects right away, but antidepressants really vary by the individual. It might not work at all. It might work great. If you see a good psychiatrist, they will often taper you up on the drug slowly to minimize side effects, so you don't even get to a therapeutic dose for awhile (most general docs don't know how to do this very well as they don't specialize in this). I'd be very surprised if you notice anything that quickly. If you're looking for a quick relaxation effect, they usually use benzos for that, although they can make you tired and they wear off. I would personally say that if you have an anxiety problem, but your life is still doing okay, the place to start is therapy with a psychologist who specializes in treating anxiety. But that does take time. Medication won't cure you, but therapy might. Medication can help with the symptoms but again, doesn't cure. Medication also has its problems -- all meds do -- and antidepressants can take a while to find the one that works for you and they have a lot of side effects, which are hard for some and really easy for others. Any antidepressant can cause start-up anxiety, although Lexapro is less likely to do that than more stimulating ones. So we don't know how you're going to feel when you start. How we felt might not be anything like how you feel. They're that variable. When I took it, my problem was a different one than you have, and it didn't work much for me. The main side effects I had were sweating and a very odd head pressure. I've been on several different ones and every one has been a very different experience from every other one. If you're able to do the presentation, I'd wait if it were me because one side effect more likely than increased anxiety is sedation. A lot of side effects are just when you start, and others stay around as long as you take it. Also, if it were me, again, I'd see if therapy helped first so I didn't have to take a medication that can be hard to take and hard to stop taking, but when my life got out of hand, I took them because at that point it was necessary. And if I was going to take them, I'd consult with a psychiatrist, the specialists in these meds rather than a general doc who does a thousand different things every day and is therefore a master of none of them. That's how I approach it. You do what seems right to you. But your question can't be answered; only taking it will answer your questions about how it will make you feel or it will work.