In 2007 Michael Maitland left home for university and in the years that followed he developed depression, OCD and, almost fatally, anorexia.

It was only when Michael was taken to hospital in 2012, his body shutting down and his organs failing, that the family realised exactly what was happening. Later, Iain was given a bundle of letters that had been carefully saved and tucked away in a drawer - the letters he had written to Michael regularly from the autumn of 2007 when he went to university.