Encyclopedia of Health and Medicine

378 Psychiatric Disorders and Psychologic Conditions
obsessive–compulsive disorder (OCD) A psychiatric
disorder in which the person engages in
ritualistic, often repetitive behaviors to an extent
that interferes with, and may prevent, normal
function in everyday activities. OCD is a type of
anxiety disorder in which unreasonable worry
crafts the ritualistic behaviors, which are dysfunctional
methods for accommodating the worry. For
example, washing the hands seven times each
after going to the bathroom may be an accommodation
for an unrealistic worry about, or fear of,
infectious disease. Walking three times up and
down the sidewalk before entering the house
when returning from work may be an accommodation
for the unfounded fear of an intruder being
in the house or to affirm the presence of someone
who is supposed to be there.
The person generally has no conscious desire to
engage in the behaviors and may instead consciously
desire not to engage in them but is unable
to stop. This desire may become so intense as to
cause the person to avoid circumstances that activate
the behavior—for example, not using public
bathrooms to avoid hand washing rituals or entering
the home from the garage or back door to
avoid entry rituals. OCD begins in childhood for
many people and often progresses in adulthood.
Other psychologic conditions, such as DEPRESSION
and PANIC DISORDER, are also common in people
who have OCD.
ANTIANXIETY MEDICATIONS and ANTIDEPRESSANT
MEDICATIONS, notably selective serotonin reuptake
inhibitors (SSRIs) and tricyclics, are often effective
in relieving symptoms. The tricyclic antidepressants
clomipramine and imipramine are especially
effective. BEHAVIORAL MODIFICATION THERAPY and
COGNITIVE THERAPY help the person gain control
over his or her thoughts and actions regarding
compulsive behaviors. OCD, like other psychologic
conditions, likely has genetic as well as environmental
foundations. For many people OCD is a
chronic condition that requires lifelong treatment,
though treatment successfully manages symptoms
to allow normal participation in daily life, work
situations, and social interactions.
See also GENERALIZED ANXIETY DISORDER (GAD);
NEUROSIS; PSYCHOSIS.
oppositional defiant disorder A behavior disorder
in which a child expresses open defiance and
constant challenge toward parents, teachers, and
other adult authority figures. The behaviors
appear intended to create irritation and annoyance
and consist of
• persistent arguing with adults
• questioning or refusing to follow rules
• deliberately hurtful comments
• perpetually angry demeanor
The expression of defiant behaviors commonly
occurs during two periods: around age three and
at ADOLESCENCE. Some researchers believe oppositional
defiant disorder reflects difficulty the child
experiences in the attempt to separate from parents
or primary caregivers to establish his or her
independent identity.
The diagnostic path begins with a comprehensive
medical examination to rule out physical
causes for symptoms and may include evaluation
for substance abuse. Treatment is often a combination
of BEHAVIOR MODIFICATION THERAPY and COGNI-
TIVE THERAPY for the child individually and
sometimes for the whole family. Most children
respond to treatment.
See also ATTENTION DEFICIT HYPERACTIVITY DISORDER
(ADHD); CONDUCT DISORDER.