Diagnosis is, to me, one of the most difficult parts of being a therapist. On principle, I'm against diagnosing clients; however, as we are a managed-care driven society, I must. This book is incredibly helpful in giving key questions to ask to differentiate between similar disorders (I struggle with depressive disorder NOS and dysthymia). Also, the mnemonics are great. Some are incredibly useful, such as DIGFAST for bipolar disorder and SIEGCAPS for major depressive disorder. Some, however, are just silly; the one for panic disorder had me laughing out loud. This book is a real treasure that I will use time and again.