Transcript Psychopathology

Psychopathology
Introduction
• http://vle.ccs.northants.sch.uk/mod/res
ource/view.php?id=6874
• Some explanations are more
appropriate for explaining certain
disorders than others.
• No single explanation accounts for all of
the complex and diverse aspects of
particular mental disorders
• There is a complex interaction of
biological, psychological and
environmental factors.
• Each model (or approach) has particular
treatment associated with it.
• Some therapies are more suited to
particular disorders than others.
• Researchers use various methods to
investigate the effectiveness of
therapies.
• Results can be difficult to interpret due
to methodological, practical and ethical
issues.
In order to be scientific, consider:
• Does the research compare like with
like?
• E.g. one group in treatment compared
with one group receiving a different
treatment.
• But
• Individual differences make it difficult to
compare accurately.
2.
• Investigator effects
• Treatments are sometimes effective
during the clinical trials but not so
effective when delivered by a different
practitioner.
3.
• The effects of previous treatment.
• Ideally, patients on a research
programme should stop any other
treatments well before the trial begins.
This doesn’t always happen.
4.
• Are improvements really due to the
therapy being trialled?
• Patients often show improvements in
trials, but not necessarily due to the
treatment.
• Double-blind trials can be helpful in
medical trials. They are usually
impossible when using psychological
therapies.
5.
• Measuring effectiveness
• What do we mean by ‘cure’?
• Does ‘coping better’ mean someone is
‘cured’? If someone is ‘less afraid’ of spiders
are they ‘cured’ of spider phobia or do they
have to be able to handle them freely in
order to be ‘cured’?
• Passage of time is important too. Some
therapies take longer to take effect than
others. At what point should the measure
take place?
Classification and diagnosis
• Central to the biological model is the idea
that mental disorders can be classified and
diagnosed.
• A diagnostic system has certain
characteristics:
• Categories are mutually exclusive – they don’t
overlap
• Categories are jointly exhaustive – they cover
everything between them
• Features of a disorder are either present or
absent
• The system must be reliable and valid.
Advantages of classification
• 1.Helps communication with the patient
and mental health professionals
•.
Advantages of classifying
• 2. Aetiology: no obvious single cause
for most mental disorder, but certain
disorders are more reliably associated
with particular causes or aetiologies.
Knowing the diagnosis can help inform
research into the underlying cause
Advantages of classifying
• 3. Treatments are often specific to
certain disorders, e.g. symptoms of
schizophrenia often respond well to
anti-psychotic drugs but not to antianxiety drugs.
• Reliable diagnosis helps to identify
which treatment to use.
Advantages of classifying
• 4. An accurate diagnosis provides
valuable information about the likely
development of the disorder
(prognosis).
• This helps for forward planning of
treatment and management.
Disadvantages of classification
• 1. Misdiagnosis
• Leads to inappropriate treatment and
management
• 2. Assumption of separate categories
• In real life, there are grey areas and there
are also degrees of depression, anxiety etc.
• 3. Labelling
• Can be helpful, but can also be stigmatising
• 4. Historical and cultural context
• Clinicians may incorrectly diagnose if they are
unfamiliar with the culture of the patient.
Reliability and validity
• Classification is only useful if those using it are in
agreement.
• Lack of objective tests for mental disorders make
certainty more of a problem.
• DSM IV –R tries to deal with these, but problems still
exist
• Low reliability undermines validity.
• Descriptive validity = ability of diagnostic systems to
describe syndromes accurately and differentiate
between categories
• Predictive validity = ability of the systems to predict
the course of the disorder and the outcome of any
treatment.
• Both descriptive and predictive validity are high for
certain disorders, but not for others.
The classification systems
• ICD – The international Classifications System
for Diseases
• Developed by the world health organisation
(WHO).
• DSM IV R – The Diagnostic and Statistical
Manual of Mental Disorders
• Developed by American Psychiatric
Association (APA).
• Both categorise disorders on basis of signs
and symptoms
• Do not contain causal explanations.
• Both need regular updating
ICD
• Identifies 11 general categories of
mental disorders
• Main function – to enable the collection
of general health statistics
• Mental disorders form only one small
section of the manual.
• 11th version planned for 2011
• APA and WHO are working to make the
ICD and DSM more consistent
DSM
• Used mainly for diagnosis and research
purposes
• Categories consist of groups of symptoms
• For nearly half of the disorders, symptoms
must be sufficient to cause ‘clinically
significant distress or impairment in social,
occupational, or other important areas of
functioning.
• The ICD -10 does not include the social
consequences of disorders.
Important difference between ICD and DSM
• DSM has 5 different axes (levels) of
different aspects of disorder or disability
Axis 1
• clinical disorders, including major
mental disorders, as well as
developmental and learning disorders
• includes depression, anxiety disorders,
schizophrenia)
Axis II
• underlying pervasive or personality
conditions, as well as mental
retardation
• includes antisocial personality disorder
and problems of intellectual
development.
Axis III
• Acute medical conditions and physical
disorders
• Includes medical problems that could
lead to or exacerbate mental disorders
e.g. brain injuries)
Axis IV
• Psychosocial and environmental factors
contributing to the disorder
Axis V
• Global Assessment of Functioning or
Children’s Global Assessment Scale for
children under 18years (on a scale of 0 –
100)
• The scale is used to rate the ability to
function socially, psychologically and at
work.
• A score of above 90 = superior functioning
• A score of below 30 = serious impairment.
Reliability
• Several clinicians arrive at the same diagnosis
for a particular patient
• Consider why early versions of the ICD and
DSM might be unreliable.
• Unclear definitions
• Different interviewing techniques
• More detailed definitions in place
• Standardised interview schedules (PSE)
Present State Examination developed by Wing
et al. (1974)
• Computer programmes such as CATEGO
which eliminates personal bias.
Cultural issues
• International acceptance of the ICD and DSM
• Other diagnostic symptoms are not in
frequent use.
• Pakistan, India and China aren’t in full
agreement with western classification
systems.
• The Chinese include ‘neurasthenia’ (weakness
of the nerves) which covers many disorders
including schizophrenia.
KEY POINTS
• Psychology is a broad discipline which
encompasses many different theoretical
perspectives (or paradigms)
• In the field of psychopathology, several
different models are used to explain the
cause of mental disorders and to
suggest methods of treatment.
• The models are split into two major
categories: biological and psychological
KEY POINTS
• All models offer explanations for mental
disorders and suggest treatment
• Some of these are more appropriate to
certain disorders than others.
KEY POINTS
• Therapies are suggested by all the models. It
is important to make sure the most
appropriate and effective therapy is chosen
for each individual patient.
• The effectiveness of treatment is assessed by
the research studies. It is important to be
aware of some of the methodological and
ethical issues that surround such research as
this can affect the accuracy of the
conclusions.
KEY POINTS
• Classification systems have been
developed to make the process of
research and diagnosis simpler. The
major systems in use across the world
are DSM-IV-R and ICD-10.
• They have been revised many times
and are now very similar to each other.
KEY POINTS
• There are several issues surrounding
the classification and diagnosis of
mental disorders.
• One major issue = reliability and
validity of diagnostic criteria.