I found this interesting. A succinct way to understand OCD.

“Psychologists have identified three types of dysfunctional belief important in the development of OCD. The first is an inflated sense of threat and personal responsibility. The second is perfectionism and intolerance of uncertainty. The third is a belief in the over-importance of thoughts and the need to control them. To be clear, to have one of these dysfunctional beliefs is not to have OCD, but it does increase the chance that someone will develop OCD, because they will incorrectly process the intrusive thoughts that are common to most people.”

From “The Man Who Couldn’t Stop,” by David Adam