|Image courtesy of Stuart Miles/
Some of these compulsions have a foundation in common sense, such as locking doors and windows. Others are completely irrational, like tapping objects or performing tasks a certain number of times.
Even if a check begins as sensible, though, OCD will render it irrational, as the condition compels sufferers to repeat it, over and over again, until it feels 'right'. Without that feeling of 'rightness', doubt remains as to whether the associated risk has been eliminated.
Reaction to the Germanwings air crash last month - apparently caused by the co-pilot deliberately flying the plane into a mountainside - reminded me that it's not just OCD sufferers who find it hard to tolerate doubt.
Within a day or so of the tragedy, a number of airlines and aviation authorities implemented regulations that banned sole occupancy of a cockpit, to prevent one person from locking themselves in and assuming control of a plane.
I immediately wondered how that could provide any kind of guarantee. While it's a wise precaution, it's hardly an infallible one. With a relatively small crew on most aircraft, what's to stop two like-minded individuals collaborating and then biding their time until they find themselves on a flight deck together?
I read numerous comments online in response to the crash, from people vowing never to fly again, in spite of the new security procedures. Perhaps they're right. Never mind the fact that these measures aren't infallible, they might actually lead to a different risk. After all, it only became standard to lock cockpits following the terrorist attacks of 9 September 2001, which is what enabled this latest tragedy.
Yet avoidance of flying isn't going to protect these worried passengers from harm forever; the world holds an infinite number of other, equally unpredictable hazards. We can't mitigate against every possible danger in air travel, but nor can we in any other walk of life.
Daily, the news reminds us that potential disaster lurks everywhere: a landslide engulfs a car, a sink hole opens up under one property, while a gas explosion demolishes another...and so on and so on. The joking reassurance, 'If you think about it too much, you'd never go out', is no reassurance at all - staying in is no safer!
A lot of people struggle to handle uncertainty, especially in relation to their own mortality. We all have to find a way to live with this, though, whether we have OCD or not; we really don't have any other choice.