The Nigerian militants who rely on drugs to fight their fears and the displaced people taking them to forget the violence. Kate Adie introduces correspondents' stories. Sally Hayden reports from Madhugiri where the battle against Boko Haram is creating a growing problem with drug abuse. Tom Stevenson is in Diyarbakir, the Turkish city which has for decades, been at the heart of the conflict between Kurdish rebels and the state. Caroline Eden explores the Brodsky synagogue in Odessa and sifts through its archive which tells of controversies old and new. Rahul Tandon finds out that what you wear, what you drive and how you speak can affect which shops and restaurants are willing to take your money in India. It is, he says, one of the most class-conscious societies in the world. And David Chazan once owned a work of art worth tens of thousands of pounds – not that he knew it – opting instead to replace it with a coat of blanc cassé on the walls of his Paris flat.