Obsessive-Compulsive Disorders by Ronan S. Estoque, DPA (January, 2008)

Obsession in Oxford Interactive Encyclopedia is defined as an idea/image that repeatedly intrudes on the mind of a person against his will. Compulsion on the other hand is an irresistible impulse to behave in a certain way. A combination of the two words denotes a fixated ritual where a deviation is difficult (if not impossible) for the subject experiencing the disorder.

Obsessive-compulsive disorder takes many forms, including excessive hand washing, fear of creating hazards for others, a need for order, anxiety over germs or contamination, repetitive checking of irons, ovens and door locks, and fear of harming others with knives or similar sharp objects.

The Most Common Expressions of OCD are:


Relationship Substantiation. A compulsive search for tiny but disqualifying flaws in a partner or spouse. Romances and marriages often do not survive the scrutiny.
Fear of Injuring Other People. A preoccupation with the idea of losing control and injuring or even killing others, it often results in a terrified avoidance of knives, scissors or other sharp objects.
Responsibility Anxiety. A broader fear of negligently hurting others. Sufferers will smooth out throw out rugs or pick up trash from sidewalks so strangers won’t trip.
Scrupulosity. An intolerance of disorder or asymmetry, this is a fastidiousness that goes beyond mere tidiness.
Contamination Anxiety. The hand washing compulsion. Fears contamination can spread from hands to other objects, leading to clothes, belongings and even walls being washed.
Sexual-Orientation Fears. A person who may have no moral or social objections to homosexuality becomes fixated with discovering (homosexuality) in themselves.
Obsessive Hypochondria. This can be a tricky one, often confused with ordinary hypochondria. OCD sufferers tend to disqualify reassurances from doctors with what – if worries, misdiagnoses and other medical errors. Behavior therapy (i.e. exposure and response prevention) is one of the clinical success stories that have been reported. Meaning, constant exposure tends to rewire the brain, reinforcing the perception that such is not that bad, and that whatever it is, such is not a big deal.

The random firing of neurons will correct itself where underestimating things would be much preferable as opposed to overestimating things.

References

Oxford Interactive Encyclopedia, 2000.
Kluger, Jeffrey. When Worry Hijacks the Brain. Time, Vol. 170, No. 7, 2007.