OCD: it’s like having a bully inside your head – People | Popular Stories, Obituaries & More | The Irish Times – Fri, Apr 25, 2014.

“..the disorder is not always outwardly evident, as sufferers often keep the thoughts they grapple with a secret…

Nicknamed “the doubting disease”, the disorder is associated with hyperactivity in the part of the brain responsible for regulating distress. It also sets off compulsive behaviour, such as repeatedly checking locks and switches, which temporarily quells this sense of alarm…”