BBC HomeExplore the BBC
This page has been archived and is no longer updated. Find out more about page archiving.

17 September 2014
Accessibility help
Human Body & MindScience & Nature

BBC Homepage

In Human Body & Mind:

Contact Us

You are here: BBC Science > Human Body & Mind > The Mind > Mental disorders

Overriding obsession

Thought control

All of us can think of an occasion when an idea or mental image has popped into our head without warning. These might be completely senseless, or they might be things we know we shouldn't do. But most of us are never bothered by these thoughts and we can easily forget them.

A distressed OCD sufferer
Obsessive-compulsives are tortured by distressing mental images


Intrusive thoughts, or obsessions as psychologists call them, affect everyone. But some people can't get rid of them as easily as the rest of us. People who suffer from obsessive-compulsive disorder (OCD) are plagued by intrusive thoughts that they can't banish from their mind, no matter how hard they try.

Obsessive-compulsives are tortured by these thoughts, which they find profoundly disgusting and distressing. The obsessions experienced by OCD sufferers can be grouped along several common themes.

Common obsessions

  • Fears of contamination by germs, dirt or chemicals
  • Fears of flooding the house, causing a fire, or being burgled
  • Aggressive thoughts about physically harming a loved one
  • Concerns about exactness or symmetry
  • Intrusive sexual thoughts or urges
  • Excessively doubting own morals or religious convictions
  • A need to tell, ask or confess
Running tap
Washing your hands again and again is one of the many symptoms of OCD

Daily rituals

Many of us carry out daily rituals consisting of a series of tasks that we might otherwise forget. For example, checking that all the doors and windows are locked before we go to bed at night is a routine that guards against burglary. But in OCD, these rituals spiral out of control.

OCD sufferers are driven to carry out complex rituals known as compulsions, which are triggered by obsessions. An obsessive-compulsive might check their doors and windows 50 to 100 times when an obsession about security gets stuck in their head. Obsessive-compulsives are completely powerless to control their compulsions.

Most OCD compulsions are logically related to their obsession. For instance, sufferers carry out cleaning rituals in order to rid themselves of contaminants.

Common compulsions

  • Cleaning - repeatedly washing hands or wiping household surfaces for hours on end
  • Checking - repeatedly questioning whether lights switches are turned off, or appliances are unplugged
  • Counting strings of numbers for hours on end
  • Arranging - needing cutlery or furniture ordered in a certain way
  • Repeating words or sentences
  • Completing - performing a task in exact order again and again, until it is done perfectly (if they are interrupted, they often need to start all over again)
  • Hoarding - collecting useless objects
people in the street
OCD could be much more common than we currently think

More common than we thought

Until the 1980s, about 2 in every 1,000 people were thought to be affected by OCD. Recent studies have revised this figure to 2 out of every 100 people. But it could be even more common, because sufferers often conceal the disorder from other people.

Some OCD sufferers are so afraid of being misunderstood by others that they become very skilful at hiding their symptoms, and can appear entirely normal. In other cases, symptoms can be so severe that sufferers receive disability compensation.

Obsessive personality

Researchers have found that people with OCD often score very highly for particular personality traits. These include:

  • Neuroticism - anxious and keen to avoid dangerous situations
  • Impulsivity - a tendency to engage in activities that bring instant gratification
  • Responsibility - an exaggerated sense of responsibility for their actions
  • Indecisiveness - a tendency to take time in making decisions
  • Perfectionism - a need to get everything to feel right

Perfectionism is one of the most common personality traits in OCD. Indeed, some researchers have described obsessive-compulsives as the ultimate perfectionists.

Related Links

Science Homepage | Nature Homepage
Wildlife Finder | Prehistoric Life | Human Body & Mind | Space
Go to top

About the BBC | Help | Terms of Use | Privacy & Cookies Policy