What will you get from this book? You will gain a better appreciation for why people break down, but you will also, perhaps as I did, come to realise the tenuous grip that even the most educated and wise individuals - even experts in a field in which they find themselves victim - have on their mental state. Hopefully it will inform, from a first-person perspective, on how you should tackle such issues. On the other hand, do not read this book to learn about the formalism regarding clinical psychology - find a more modern book.
I read this book a while ago, but it is split into two parts:
1. The autobiographical account. This is the most candid account that I have ever read someone give of themselves. He is brutally and openly honest about the causes of his mental breakdown and he does not fill the reader with blind optimism. I will give no spoilers away. In my opinion, this is must-read material.
2. This is the part of the book in which Sutherland attempts to give a 'breakdown' (terrible pun - I don't deserve to live) of clinical psychology. It is very, very outdated and I do not recommend that any of it be read.