That's exactly what it is. I almost died from eating too many hash brownies in Hong Kong a few years back. You eat a brownie, don't feel anything, after about 10 min you figure you better have another one, and it just goes on like that a couple more times and then BAM it all hits you at once. I puked for hours, took me about 3 days to recover. My friends found me straddling the rail on a balcony on the 6th floor and I remember convincing myself that I had permanent brain damage and was never coming down and wondering if it would just be better to die---but I don't think I was trying to kill myself.