Our best friends, gal-pals, bromances, Twitter followers, Facebook friends, long distance buddies and WhatsApp threads define us in ways we rarely openly acknowledge. There is so much about friendship we either don't know or don't articulate: why do some friendships last a lifetime, while others are only temporary? How do you 'break up' with a toxic friend? Can men and women really be platonic? And maybe the most important question: how can we live in the most interconnected age and still find ourselves stuck in the greatest loneliness epidemic of our time? It's killing us, making us miserable and causing a public health crisis. What if meaningful friendships are the solution, not a distraction?

Kate Leaver's much anticipated manifesto argues that friendship can cure the modern malaise of solitude, ignorance, ill health and angst. She looks at what friendship means, how it can survive, why we need it and what we can do to get the most from it. From behavioural scientists to best mates, Kate finds extraordinary stories and research, drawing on her own experiences to create a fascinating blend of accessible 'smart thinking', investigative journalism, pop culture and memoir.