T hree months before our friend took his own life, a group of us took him on holiday for a fortnight. He was 17 and had finally let us talk him into taking him away. He’d been diagnosed with severe depression and for months we had watched helplessly as the person we knew crumbled from the inside. Naively, we thought a holiday might help. I’d first met Simon* when a schoolteacher made us lab partners in human biology in our first year of sixth form college.