Introduction
Obsessive-compulsive disorder is characterised by the
occurrence of either obsessions, compulsive rituals or,
most commonly, both.1
Obsessions have four essential
features: they are recurrent and persistent thoughts,
impulses, or images that are experienced as intrusive and
cause great anxiety; they are not simply excessive worries
about real life issues; the aff ected individual attempts to
ignore, suppress, or neutralise them with some other
thought or action; and the aff ected individual recognises
that these thoughts are a product of his or her mind.1
Examples of obsessions include unwanted thoughts or
images of harming loved ones, persistent doubts that one
has not locked doors or switched off electrical appliances,
intrusive thoughts of being contaminated, and morally or
sexually repugnant thoughts (eg, intrusive thoughts of
behaving in a way that violates one’s morals or runs
counter to one’s sexual preferences).
Compulsions are repetitive behaviours (eg, repetitive
hand washing, ordering, or checking) or mental acts (eg,
repetitive praying, counting, or thinking good thoughts
to undo or replace bad thoughts) that the aff ected
individual feels compelled to do in response to an
obsession, or according to rigid rules (eg, checking that a
light switch is turned off by switching it on and off
exactly ten times). Compulsions are aimed at preventing
or reducing distress, or preventing some dreaded event.1
However, they are excessive or not realistically connected
to what they are intended to prevent.
Obsessive-compulsive disorder is a symptomatically
hetero geneous condition, in which various diff erent kinds
of obsessions and compulsions exist. However, research
indicates that certain obsessions and compulsions tend to
co-occur to form fi ve main dimensions:2
• obsessions about being responsible for causing or
failing to prevent harm; checking compulsions and
reassurance-seeking;
• symmetry obsessions, and ordering and counting
rituals;
• contamination obsessions, and washing and cleaning
rituals;