Mental disorders
are equivalent to
physical disorders
= illnesses.
All behaviour is governed
by the brain. Changes or
flaws in brain function lead
to disordered behaviours.
Phineas Gage had a spike through
his head which removed a large part
of his brain when he was working on
the train tracks and developed
aggressive behaviour post-accident.
Mental disorders are created by
biological causes: genes,
biochemical substances,
neuroanatomy, and/or
microorganisms.
EG'S OF HOW BIOLOGICAL FACTORS CAN CAUSE PSYCHOLOGICAL DISORDERS
GENES
A person's genes
heavily influence
the development of
their body.
Twin studies have shown high
concordance rates. EG KENDLER
ET AL (1991) found that MZ twins
are at 26% v DZ twins at 16%
concordance rate for bulimia
nervosa.
Genes are also instrumental in the production of
certain neurotransmitters and hormones such as
serotonin. A lack of serotonin is linked to
depression.
BIOCHEMICAL
SUBSTANCES
Neurotransmitters and hormones affect brain function.
A lack of noradreneline and serotonin has been linked to depression.
BUNNEY ET AL (1965) found that an excess of
serotonin has been linked to anxiety disorders.
NEUROANATOMY
Brain structure can cause
disordered behaviours.
Schizophrenia may be
caused by abnormal
neuroanatomy. Many
schizophrenics have
ventricles in their brains.
However not ALL
schizophrenics have
ventricles in their brains.
eg Phineas Gage.
MENZIES ET AL
(2007) found that
OCD patients had
abnormalities in
areas of their
brains that
regulate control.
MICROORGANISMS
Some
disorders are
caused by
biological
organisms
infecting the
brain.
General Paresis is an example of this - it
is also known as neural syphilis. (STI)
In the third stage of
syphilis the brain is
infected and tissue is
destroyed by the
bacteria.
EVALUATION
OF THE
BIOLOGICAL
APPROACH
STRENGTHS
Use of brain scanning
techniques has identified
biological aspects in many
psychopathologies.
Research into genetic tendencies
has revealed that hereditary does
affect the likelihood of developing a
disorder... though concordance
rates are never 100%.
It has lead to more
acceptance and
humane treatment of
those suffering.
Somatic treatments have
been shown to have had
great affect with some
suffers of mental
disorders.
WEAKNESSES
The biological approach is
reductionist. Only the physical
aspects are taken into account when
really a full picture of the causes of
the disorder should be considered.
Somatic treatments are never
effective for all suffers of
mental disorders. Drugs are
largely ineffective for
conditions such as phobias,
for eg.
Abnormal
biochemistry could
be an EFFECT rather
than a CAUSE of
mental illness. The
link is correlational.
WATSON ET AL
(1998) found that
when he isolated
monkeys from
their social ground
they had a
reduced
production of
serotonin.
SO environmental factors can affect brain
chemistry and may be the root of some disorders.