Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: I was disappointed

This book was a disappointment to me. I have the 4th edition, and was hoping to find new information on tryptophan. Nope, same mistakes as the previous edition, and same dated material regarding it still being banned in the US. This book comes from the estate of Phyllis, and I suppose that explains why the info is incorrect about the tyrptophan - tryptophan is currently available at most vitamin shops.