Pryde's book is just this side of very good. The two drawbacks I found include that it is relatively short, which is a net negative when discussing a complicated subject, and that the writing style is (probably deliberately) textbook rather than compelling. It reads like she is transferring notes from a teaching course into paragraphs of a short book, which she probably did.
Having said that, what she does write is scriptural, compassionate, balanced, well-reasoned, well-illustrated, and well-explained. And those six things together in a book are most rare, in my experience. She defines depression, discusses a handful of specific reasons for depression, and gives the biblical medicine for the cure. Nor is it just "trust God more." It is rather specific guidance using Bible passages and examples in a detailed way. The second half of the work attempts to put all of this into practical form by discussing a number of real life cases and how the principles discussed in the first half of the book apply.
Rather good book, one I think I will find myself using as a resource and handing to people both.