Psychopathology

Introduction

• http://vle.ccs.northants.sch.uk/mod/resource/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 anti-anxiety 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.