Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Very insightful

Having dealt with depression for six years, I found this book to be a very useful eye-opener; I don't think anything I've read has helped me heal as much as Dr. Gregg's. It will enable you to find and deal with the root causes of many of the issues that worry or upset you and to raise your self-esteem. There were a couple ideas in the book I didn't entirely agree with, but then it's also a question of interpretation. Highly recommend.