complexA term used in medicine to
mean a group or combination of related
signs and symptoms that form a syn-
drome (as in Eisenmenger complex), or
a collection of substances of similar
structure or function (as in vitamin B
complex). In psychology, a complex (for
example, the Oedipus complex) is a
group of unconscious ideas and memo-
ries that have emotional importance.
complianceThe degree to which pat-
ients follow medical advice.
complicationA condition resulting from
a preceding disorder or from its treatment.
compos mentisLatin for “of sound mind’’.
compressA pad of lint or linen applied
under pressure to an area of skin. Cold
compresses soaked in ice-cold water or
wrapped around ice help to reduce pain,
swelling, and bleeding under the skin
after an injury (see ice pack). Hot com-
presses increase the circulation and
help to bring boils to a head. A dry com-
press may be used to stop bleeding
from a wound or may be coated with
medication to help treat infection.
compression syndromeA collection
of localized symptoms such numbness,
tingling, discomfort, and muscle weak-
ness caused by pressure on a nerve.
compulsive behaviourSee obsessive–
compulsive disorder.
computed tomographyAnother name
for CT scanning.
computer-aided diagnosisThe use
of computer technology in diagnostic
tests and procedures. Probability-based
computer systems store information on
thousands of cases of different disorders
detailing exact type, location, duration,
symptoms, medical history, and diagno-
sis. A patient’s symptoms and medical
history can be entered into a computer,
which then compares the details with
existing data and produces a list of the
most likely diagnoses. Such technology
is not currently in common use in hos-
pitals, but is of value for people isolated
from medical services, such as oil-rig
crews. Computers programmed to inter-
pret visual data, such as abnormal cells,
have potential use in certain types of
blood test and cervical smear tests. Com-
puters are also used in investigative
procedures such as CT scanningand MRI.conceptionThe fertilizationof a woman’s
ovumby a man’s sperm, followed by
implantation of the resultant blastocyst
in the lining of the uterusthus starting a
pregnancy. (See also contraception.)
concussionBrief unconsciousnessdue to
disturbance of the electrical activity in
the brain following a violent blow to the
head or neck. Common symptoms fol-
lowing concussion include confusion,
inability to remember events immedia-
tely before the injury, dizziness, blurred
vision, and vomiting. If symptoms persist,
or new ones develop, such as drowsiness,
difficulty breathing, repeated vomiting, or
visual disturbances, they could signify brain
damage or an extradural haemorrhage.
Repeated concussion can cause punch-
drunksyndrome. (See also head injury.)
conditioningThe formation of a speci-
fic response to a specific stimulus. In
classical conditioning, a stimulus that
consistently evokes a particular response
is paired repeatedly with a second stim-
ulus that would not normally produce the
response. Eventually, the second stimu-
lus begins to produce the response
whether the first stimulus is present or
not. In operant conditioning, attempts to
modify behaviour are made through a
system of rewards and/or punishments.
The theory that inappropriate behav-
iour patterns in some psychological
disorders are learned through condi-
tioning and can be modified by the
same process underlies behavioural
psychology (see behaviour therapy).
condomA barrier method of contracep-
tionin the form of a thin latex rubber or
plastic sheath placed over the penisbe-
fore sexual intercourse. Condoms also
offer some degree of protection against
sexually transmitted infections.
condom, femaleA barrier method of
contraceptionin the form of a sheath
inserted into the vaginabefore sexual
intercourse. It also offers some protection
against sexually transmitted infections.
conduct disordersRepetitive and per-
sistent patterns of aggressive and/or
antisocial behaviour, such as vandal-
ism, substance abuse, and persistent
lying, that occur in childhood or adoles-
cence. (See also behavioural problems
in children; adolescence.)COMPLEX CONDUCT DISORDERSC