DEFINITION:
The phrase “obsessive-compulsive disorder (OCD)” (also known as “anankastic personality disorder”) refers to a mental disorder characterized by intrusive thoughts or preoccupations (the “obsessive” component), together with an irresistible impulses to perform certain routine actions repeatedly (the “compulsive” element).
ETYMOLOGY:
The English phrase OCDis attested from the mid-1920s. It is basically a translation of earlier terms current in the German medical literature, notably, Zwangneurose [compulsion neurosis] employed by Sigmund Freud (1856–1939), and before that, Zwangvorstellungen [compulsive ideas] used by Richard von Krafft-Ebing (1840–1902).
The adjective “obsessive” is attested from only the turn of the twentieth century; however, the related noun “obsession” is much older, dating from the late seventeenth century. Both terms are derived from the Latin past participle obsessus of the verb obsideo, obsidēre, meaning “to besiege” or “to beset.”
The English adjective “compulsive” is attested from the sixteenth century, while the related noun “compulsion” is roughly a century older. Both words derive, via Middle English and Middle French, from the Late Latin noun, compulsio, compulsionis, which in turn was derived from the Classical Latin past participle, compulsus, of the verb, compello, compellere, meaning “to drive,” “to bring together,” “to coerce,” or “to compel.”
For the etymology of the term “disorder,” see the Glossary entry, borderline personality disorder.
DISCUSSION:
Obsessions, or obsessive thoughts or preoccupations, are persistent and unwanted thoughts, urges, or mental images that the patient finds it impossible not to dwell upon.
Such thoughts may lead to feelings of anxiety, disgust, or contamination. Obsessive preoccupations are frequently of a sexual nature.
Compulsions are repetitive, routine actions that are irrational in the sense that the patient may simultaneously harbor a belief that renders the action futile or pointless. The classic example is a patient’s inability to prevent himself from checking and rechecking that a door is locked or a light switched off, despite knowing full well that he has already locked the door or switched off the light.
Other common compulsive behaviors include hand-washing, house-cleaning, counting, symmetric arranging, hoarding, and seeking reassurance.
Although there are domains of activity—such as cleanliness and symmetry—that are typical of OCD, there is no single action or combination of actions that is present in all cases.
Compulsive behavior occurs along a wide spectrum of severity. For there to be a formal diagnosis of OCD, the activity must rise to the level of impairing the patient’s ordinary daily functioning or personal relationships. In full-blown instances of OCD, compulsive behaviors may occupy an hour or more per day.
Many investigators interpret compulsive behavior as an attempt to relieve the distress caused by obsessive ideation. Compulsive acts may provide the patient with momentary psychic relief, but like other reward-seeking behaviors, they tend to increase in frequency over time.
The etiology of OCD is basically unknown, though twin studies suggest there may be a moderate degree of heritability.