The start of a new year: a time for optimism, ambitious plans to improve the world, and the grim suspicion that the first couple of months may well be a miserable slog through the deepest of winter’s gloom. But for those who fear the cold and dark ahead, help is on the horizon. Researchers in Canada are investigating a simple trick they hope will boost flagging spirits even when the days are short and frost is in the air. “People really need something to help them get through the winter, especially after Christmas,” said Dr Holli-Anne Passmore, the psychologist leading