Ch 11 - Jeff Standen

- M
Models of abnormality
diathesis-stress model states that psychological disorders
result from an interaction between genes and the
environment. Diathesis means a condition which makes an
individual more susceptible to a disorder. When the
diathesis - in this case a genetic predisposition - combines
with certain life events such as stressors, the disorder is
more likely to develop. The diathesis-stress model suggests
that gene therapy, on its own, will not provide a 'magical
cure' for psychological disorders.
Electroconvulsive therapy (ECT) ECT involves passing an
electric current through the brain which causes a brain
seizure or convulsions. It is sometimes used in cases of
severe depression, though less so nowadays, partly because
of side effects such as memory loss. Although it appears to
reduce symptoms of depression in around 60-70% of cases,
it is not clear how ECT works. However, it is known to
release a variety of neurotransmitters in the brain (Comer,
1998).
Brain surgery This is the most extreme biological treatment
for psychological disorders. It has a long history starting
with trepanning in prehistoric times, though today it is only
used as a last resort.
Evaluation of the biological model
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Greater understanding In recent years, rapid advances in
biochemistry and genetics have increased our understanding
of the biological aspects of psychological disorders.
However, this understanding is far from complete. The
complexities of brain chemistry and human genetics have
yet to be unravelled.
Inconclusive evidence The evidence is inconclusive. To
what extent does neurotransmitter activity cause
psychological disorders? What contribution do genes make
to the onset of psychological disorders? The short answer is
we don't really know. As yet, no specific genes have been
identified that make major contributions to psychological
disorders. Available evidence suggests that many genes may
contribute to psychological disorders, each having a
relatively small effect. However, the picture is far from clear
(Barlow & Durand, 1999).
Reductionism This is the reduction of something to its most
basic elements or parts. Can psychological disorders be
reduced to biological factors, as extreme versions of the
biological model suggest? The answer is probably no.
Complex mental and emotional processes are unlikely to be
caused solely by genes and neurotransmitters. At most,
biological factors probably predispose people to
psychological disorders as the diathesis-stress model
suggests. In terms of this model, psychological disorders
result from an interplay between biology and the
environment.
Cause and effect As noted in the case of the role of
hormones in depression, some biological changes may
result from, rather than cause, psychological disorders. For
example, if someone jumps out at you in the dark, it is fear
that causes the adrenaline rush, not the adrenaline that
causes the fear. In certain cases, biochemical imbalances
may be caused by (rather than causing) psychological
disorders.
The classification system Classification systems of
psychological disorders are largely based on the biological
or medical model. Critics question their claim to be
objective and scientific for the following reasons. There are
frequent and sudden changes in classifications including the
appearance of new disorders, the re-classification of existing
disorders, and the removal of other disorders - as in the
case of homosexuality. At times these changes appear to
reflect changes in attitudes in the wider society rather than
the application of scientific knowledge.
Treatment Many of the treatments suggested by the
biological model have been criticised as unethical and
ineffective. Drug treatment can have negative side effects. It
can lead to physical and psychological dependence. In
addition, it may only treat the symptoms of a disorder rather
than its cause. For example, drugs may simply readjust
neurotransmitter levels and do nothing about the situation
which caused the disorder in the first place. Many
researchers would agree with Ronald Comer that 'drugs
alone do not provide a long-term solution' to most cases of
psychological disorders (Comer, 1998).
However, many psychiatrists and patients argue that drugs
can relieve extremely distressing symptoms and place
people in a better frame of mind to overcome their disorder
(see Activity 1, Item B).
A humane approach? Supporters of the biological model
claim that it is more humane than other models. It portrays
psychological disorder as illness - something that just
happens to a person. No blame is attached to the individual
for suffering from the disorder. This is in contrast to some
psychological models which imply that people cannot cope
with life or have brought their disorders upon themselves.
However, critics are doubtful that it really helps to see
disorders as illness, since this encourages the 'patient' to
depend on the 'doctor' and not to take any personal
responsibility for their own recovery.
r
Key terms
Biological or medical model A model which states that
psychological disorders are caused, at least in part, by
biological factors such as neurotransmitter imbalance and
genetic inheritance.
Diathesis-stress model A model which states that
psychological disorders are caused by an interaction between
the environment and a condition - the diathesis - which
makes people more susceptible to disorders.