This is one of those psychology books that leans heavily towards the theoretical side than self-help. O'Connor isn't just a psychologist, but someone who has suffered from depression and brings that personal element into the book. He breaks up the book into three parts: what we know about depression (the experience, the diagnoses, the causes), learning new skills (pertaining to emotions, thoughts, behaviors, socially, medication, psychotherapy, etc.), putting the skills into practice, and a summary of the book. It's a lot of info, so if you're depressed and looking for practical tools, you'll have to do some digging and of course reading something an applying it is easier said than done. If you're a therapist, this book is a helpful overview and I liked the Mindfulness-based CBT focus with some useful exercises to use with clients. That said, although this is the second edition, it reads a bit dated (and reading it was a slog), so be aware of any changes in the DSM or medication. Perhaps it was out of the scope of this book, but O'Connor didn't address the context of depression as much in terms of depression afflicting people of different identities, or how that might play a role in perpetuating their depression. I know he's from an older generation of mental health providers, but I hope he at least acknowledges how depression might play out in minority and marginalized groups. Overall, Undoing Depression is a dense, but informational read on a pervasive mental health issue.