In my opinion, kids at that age, with their still-developing brains, can benefit so much more from behavior therapy than from chemicals. That way they truly learn right behavior from wrong behavior, rather than stifling any hard-to-deal-with emotions.

Child psychiatry is very risky business nowadays. It's hard to find the right balance of medications for growing bodies, plus many psychiatric drugs are still very mysterious.

I definitely wouldn't jump into seeing a psychiatrist about your child's issues. But it's clear you need help. I'd suggest seeing a behavioral psychologist (quite different from a child psychiatrist).

I agree with Tishie as well. With kids that young, inconsistency can be frustrating and confusing. There are resources out there, like books or web sites, that can help you figure out ways to effectively discipline your child.

Super Nanny is a show I watch often, and they've come up with a very effective technique. While this isn't the whole of the technique, an integral part of the discipline is placing the child in a specific "naughty spot," and making sure they STAY there. The first time you place them down, you get down to their level and explain exactly why they're there, in a calm, low voice. They will be inclined to get up and run away, so the second time, you simply carry the child back. During these repeated times of carrying them back, it's important that you NOT say anything, and NOT buy into the fit.

Here is a good article from their site about reducing tantrum likelihood.

Let me know how everything goes!