Depression is a kind of chronic psychic pain; there is no getting used to it. This distilled misery will afflict one in five of us at some point in our lifetimes. Philip Gold, a senior researcher at the US National Institutes of Health, knows this all too well – he has been researching it for around fifty years and has suffered it himself. In his new book, he summarises the findings of his work, in particular the dramatic progress that he and his colleagues have recently made. As he says towards the end, ‘it is difficult for me to express how excited and pleased I am by these breakthroughs after so many years of not getting to the core … of depressive illness’.

And it is an illness, he argues. Depression, Gold believes, is the normal human stress response gone horribly wrong, distorted and extended well beyond its usual duration, wreaking havoc on both the brain and the body. Owing to genetics and adverse experiences, some of us are sensitised to developing this chronic overactivation of the stress response, which not only generates feelings of fear and self-hatred but also damages the cells and tissues of the body, leading to premature coronary artery disease, diabetes, osteoporosis and strokes. Help, though, is at hand: researchers are currently developing and testing more than thirty new drugs, together with other interventions, from psychedelics and ketamine to magnetic stimulation of the brain and compounds designed to inoculate vulnerable individuals before they get depressed. Many of these will take effect within hours, instead of the weeks that traditional antidepressants take to work.

There will be those who are aggravated by this medical understanding of depression. For decades, psychiatry has squared off against its critics, successors to the ‘anti-psychiatry’ movement of the 1960s. They argue that depression (and other mental-health problems) are best thought of not as illnesses but as ‘problems