Obsessive-Compulsive Disorder (OCD) Obsessive-compulsive
disorder is defined as the presence of recurrent obsessions
(persistent thoughts, impulses, or images) or compulsions
(repetitive behaviour or thought patterns induced in an attempt
to prevent anxiety) that are excessively time-consuming (taking
more than an hour a day) or cause marked distress or significant
impairment. The subject recognises that these patterns are
excessive. Differential diagnosis of obsessive-compulsive
disorder includes generalised anxiety disorder, panic disorder,
phobias, compulsive personality disorder, and hypochondriasis.
While many of these syndromes are characterised by intrusive
thoughts, few have associated rituals. The complex tics seen in
some patients with Tourette’s syndrome may be difficult to
distinguish from the compulsions seen in obsessive-compulsive
disorder, and, in fact, there is significant overlap in symptoms
between the two disorders (Rasmussen and Eisen, 1992). Although
the phenomenology of obsessive-compul