Buzzed is a decent book, with interesting information about psychoactive molecules found in, oh, chocolate, for example (The library where I work runs on chocolate.):
... caffeine and theobromine may not be the only psychoactive compounds in (chocolate). A recent report has indicated that one component of chocolate is very similar to the natural chemical in the brain that interacts with our THC receptors -- the receptors to which the psychoactive compound in marijuana binds. Although the concentration of this compound is quite low in chocolate (it was estimated that one would have to eat twenty-five pounds of chocolate to stimulate the receptors as much as a typical dose of marijuana), it is possible that its presence could supplement the natural THC-like compound in the brain enough to produce a subtle effect. These results have led some to speculate that the vague sense of well-being and happiness that some people report in response to chocolate may be related to the interaction of the subtle drug effects associated with low-dose caffeine with those associated with activating the natural THC receptors in the brain.I think the reader is cheated by this report. "the natural chemical in the brain" is anandamide. It is also produced in the womb.
And why did the authors not name the other psychoactive molecule in chocolate? Phenylethylamine, or PEA, is an amphetamine-like substance. THC and PEA bind to the same receptors that anandamides in the womb bind to.
Like I said, this is a decent book. But not as good as From Chocolate to Morphine, by Andrew Weil, M.D. and Winifred Rosen. That one is highly recommended.