I'm a Steven Pinker fan...I really appreciate his optimism about the state of the world, and the future of the world, an optimism which he supports with a lot of engaging evidence.
So I encourage having a look at his book, Enlightenment Now. It is a sequel to another of his books (Better Angels of our Nature) which I have reviewed earlier on this blog.
I don't agree with everything he says, but I do also embrace a spirit of optimism about things, and an attitude that the many problems we have in our lives, or in the world, can be solved or at least improved with continued care and effort.
This type of book is a good accompaniment to a study of behavioural economics and social psychology (such as the works of Daniel Kahneman), as well as optimistic data analysts such as the late Hans Rosling.
The strongest section of his book is the middle part, in which the reader is barraged with many graphs showing positive changes in the world over time. I found the other sections, with a lot of philosophizing about the enlightenment, etc. less important and engaging.
As to this book's relevance to mental health? I hope we might all embrace a spirit of optimism about the pathways of our lives. Past adversity in life does not necessarily predict a guaranteed future life of suffering. There is work to be done, to build a better, happier life, regardless of the hardships of our origins.
In the cognitive theory of depression or anxiety, we understand that thoughts may specifically focus on pessimistic or even catastrophic interpretations of observations; much information in our modern world is distilled to emphasize catastrophe or adversity (non-catastrophes are less likely to become headlines), so this information is natural fuel to a depressive or anxious state. An optimistic but highly rational book such as Pinker's could be understood as a type of cognitive therapy for a modern consumer of news.
Progress in the world may also translate overall to improved mental health...but I suspect we would see the most robust improvements in those areas which have the least current services.
A peril of such a strongly optimistic text can be that it fails to empathize sufficiently with those who continue to suffer...or that it can seem insensitive when there continues to be horrible tragedy in the world. But I think that we are best able to help and heal from tragedy if we are not depleted, pessimistic, or even hopeless about the ongoing problems in our lives or in the world. So this book is a much-needed infusion of optimism into public debate.