Abnormal PsychologySession 3: Diagnosis of mental

disorders

Discuss reliability and validity of diagnosis

Today’s Learning Outcome

What the command term means: Discuss: Offer a considered and

balanced review that includes a

range of arguments, factors or

hypotheses. Opinions or conclusions should be presented

clearly and supported by appropriate evidence.

Diagnosis within psychology means identifying and classifying abnormal behaviour on the basis of symptoms, the patient’s self reports, observations, clinical tests or other factors such as information from relatives

What is diagnosis?

The purpose of diagnosis

To identify groups of similar sufferers so that psychiatrists and psychologists may develop explanations and treatment methods to help those groups

Billing purposes. The government and many insurance companies require a diagnosis for payment

Diagnosis

Diagnosis of Mental Disorders is difficult

Issue of drawing the line between what is seen as normal behavior and what is seen as or ‘abnormal’ behavior.

Because it is difficult to define it is also difficult to diagnose.

What do we mean by reliability and validity of diagnosis?

Reliability of diagnosis: Will different diagnosticians using the same classification system arrive at the same diagnosis?

Validity of diagnosis: Does the person diagnosed have real symptoms with a real underlying cause? (the illness is not socially constructed, the person is not faking)

1. Deviation from social norms2. Deviation from ideal mental health3. Statistical infrequency4. Failure to function adequately5. Mental illness criteria

Those making diagnoses use a combination of these factors when making their diagnosis of mental disorders. They use standardized systems which aim to increase validity and reliability of diagnosis.

What five ways of defining what is abnormal has been studied?

How are mental disorders diagnosed?

While a doctor looks for signs of disease using X-rays, scanners, or blood tests, as well as observable symptoms, the psychiatrist will often have to rely primarily on the patient’s subjective description of the problem.

This reduces validity and reliability.

Clinical interview is most commonly used means of assessment Interview usually involves face to face contact with clinician Although format may vary, most interviews cover these topics:

Identifying data: contact details, marital status, age, gender, employment, religion, employment

Description of presenting problems: What are troubling behaviours/feelings/thoughts? How do they affect functioning? When did they begin?

Psychosocial history: Information describing client’s history: educational, social, early family relationships etc

Psychiatric history: History of psychiatric illness/past treatment Medical problems/medication: Description of medical problems/medication.

May link to psychological problems

Today the clinician—often a psychiatrist—uses a standardised diagnostic system e.g. DSM-IV, ICD

How are mental disorders diagnosed?

Kleinmutz (1967) has noted that there are limitations to this interview process that can affect reliability/validity of diagnosis:

◦ Information exchange may be blocked if either the patient or the clinician fails to respect the other, or if the other is not feeling well. (e.g. what if the patient is mute?)

◦ Intense anxiety or preoccupation on the part of the patient may affect the process.

◦ A clinician’s unique style, degree of experience, and the theoretical orientation (e.g. Cognitive or biological psych) will definitely affect the interview.

Issues with clinical interviews

In addition to interviews, other methods can be used to assist with diagnosis.

These include: direct observation of the individual’s behaviour brain-scanning techniques such as fMRI and PET (especially in

cases such as schizophrenia or Alzheimer’s disease) psychological testing, including personality tests (e.g. MMPI-2) and

IQ tests (e.g. WAIS-R).

How are mental disorders diagnosed?

The Two Major Classification Systems

Diagnostic and Statistical Manual of Mental Disorders International Classification of Diseases

These classification systems are constantly being revised, mental disorders are added, deleted and reorganized in the light of new research evidence

DSM ICD

Classification Systems The two major classification systems used by western psychiatrists today, the

DSM DSM-IV –TR Diagnostic and Statistical Manual of Mental Disorders, (American Psychiatric Association, 1994) and the lCD-10 International Classification of Diseases, (WHO, 1992)

Based largely on abnormal experiences and beliefs reported by patients, as well as agreement among a number of professionals as to what criteria should be used.

This can explain why the criteria change in revisions of the diagnostic manuals, for example homosexuality was included in earlier versions of the DSM.

Some argue that the difficulties met in trying to identify haracteristics of “abnormality” reflect the fact that abnormal psychology is a social construction that has evolved over time without prescriptive and regulating definitions. It is also argued by some that the DSM-IV is gender and culturally biased. This effects the reliability of diagnosis

The DSM

While the main purpose of the ICD is the classification of disorders, the DSM classification system has the additional purpose of assisting clinicians to diagnose a persons problem as a particular disorder.

Diagnosis is important because it determines treatment.

The DSM-I was published in 1952. The DSM-II and DSM-III caused a lot of debate amongst clinicians because there was a lack of consensus of the precise listing of disorders (Davison et al. 2004).

The DSM-IV was published in 1994 and the DSM-IV-TR (text revision) was published in June 2000, and the long awaited DSM-V is coming out this year (2013).

DSM-IV-TR The classification system used in the United

States Lists more than 250 mental disorders The diagnosis of one individual is based on

five dimensions

The five dimensions of DSM-IV-TR Axis I: The major diagnostic classification, e.g.

major depressive disorder, anorexia Axis II: Related to developmental and personality

disorders (e.g. autism, anti-social personality) Axis III: Physical and medical conditions that

may worsen the disorder (e.g. brain injury, drug abuse, viruses)

Axis IV: Psychosocial stressors, all stressful events that may be relevant to the disorder (e.g. poverty, divorce, loss of job)

Axis V: Global assessment of functioning. Rates the highest level of social, occupational and psychological functioning on a scale of 1 (persistent danger) and 90 (good in all areas) currently and during the last year

Read through the descriptions of each party guest

Using some of the descriptors from Axis II (personality disorders) try to identify which personality disorder each guest has

Work individually We will compare answers when you have

finished

Have a go!

Watch the video critique of the DSM What are the issues with validity and

reliability? Remember you also need to think critically

about the source itself as well!

Task

The ICD: International Classification of Diseases

The current edition – the ICD-10 was published in 1992 by the WHO – the ICD-11 is expected to be published in 2015

Mental disorders where included in the ICD in 1952 (ICD-6)

Main purpose of ICD is to make it easier to report health statistics.

Enables universal agreement on the definitions of specific disorders or sets of syndromes – without these it would be very difficult for clinicians and researchers in different countries to communicate with each other.

The ICD identifies 11 general categories of mental disorders.

ICD 11 Mental

Disorder Categories

Reliability & Validity of Diagnosis

Use of the DSM and the ICD increase the validity & reliability of diagnosis

Diagnostic systems provide a template which the clinician can use to compare information about disorders to the condition of a particular client.

In this way, clinicians can use the same models for diagnosis.

The difficulty arises over whether classification can indeed be made effectively using classification systems.

For a classification system to be reliable, it should be possible for different clinicians, using the same system, to arrive at the same diagnosis for the same individual. (this is known as inter rater reliability)

Although diagnostic systems now use more standardised assessment techniques and more specific diagnostic criteria, the classification systems are far from perfect.

Reliability of Diagnosis

Mitchel et al. (2009) Carried out a meta-analysis of 41 clinical trials with

(50,000 patients) that had used semi- structured interviews to assess depression

General Practitioners (GPs) had an 80% reliability in identifying healthy individuals and 50% reliability in the diagnosis of depression.

GPs had problems making an accurate diagnosis of depression.

Reliability of Diagnosis

Reliability of diagnosis

Cooper et. al. (1972) When shown the same video clips, New

York psychiatrists were twice as likely to diagnose schizophrenia than London psychiatrists.

London psychiatrists were twice as likely to diagnose mania or depression than New York psychiatrists

Reliability of Diagnosis

Spitzer and Williams (1985) Showed that psychiatrists only agree in diagnoses

about 50% of the time.

Issues surrounding the validity of diagnosis

The labelling of patients with certain disorders may affect the

practitioners perceptions of them (compare with researcher bias),

patients may act the label that has been given to them (self fulfilling

prophecy). The label itself may simplify a problem that is highly

complex

People may fake mental illness in order to avoid punishment (The

insanity defense)

There are significant individual differences for mental disorders. An

individual may have multiple mental disorders

Validity of diagnosis

Temerline (1970) Clinically trained psychiatrists were influenced in

their diagnosis by hearing the opinion of a respected authority (expert influence)

Participants watched a video-taped interview of a healthy individual.

The authority claimed, even though the person only seemed to be neurotic (distress where behaviour is not outside social norms, patient has not lost touch with reality) he was actually psychotic (behaviour is outside social norms, loss of touch with reality)

Comer (2004)•Over inclusion and ‘patholologizing’ problems•The DSM keeps expanding•According to Comer 48% of Americans might qualify for a diagnosis on the DSM. •E.g. mood changes with the menstrual cycle should that really be seen as ‘Pre Menstrual Dysphoric Disorder’? This could be seen as ‘pathologizing’ what is normal behavior for women (gender bias).

Validity of diagnosis

Key Study: Rosenhan (1973) Covert Observation: On being Sane in Insane Places (pg 142)

The impact of Rosenhan’s (1973) classic study:

on being sane in insane places In the 1960s and 70s there was some concern among

psychiatrists that they gave diagnosis of schizophrenia too readily.

There was an even greater concern that many people where admitted to mental hospitals when they were not mentally ill, and once admitted they were detained and given treatment without their informed consent.

Rosenhan’s key study supports this and led to the revision of the DSM.

Rosenhan's study raises questions about the content validity of the DSM.

Content validity being whether the DSM actually measures what it sets out to measure.

The impact of Rosenhan’s (1973) classic study: on

being sane in insane places Validity is always going to be a problem for mental health workers –

because unlike physical illnesses – the symptoms are not clear cut

E.g. a person suffering from schizophrenia may or may not exhibit paranoia, they may or may not hear voices.

Rosenhan’s research showed the low level of validity in the diagnosis of mental illness

However – the diagnosis was high in inter rater reliability – since nearly all the ‘pseudo patients’ where given the diagnosis of schizophrenia – but this was not a valid diagnosis.

This shows that a diagnosis may be high in reliability and low in validity at the same time.

Each edition of the DSM attempts to improve both the reliability and validity of diagnostic criteria.

Look at page 142 in your textbook Answer the questions about Rosenhan’s

study in the ‘Be a critical thinker’ box

Task

A method to improve reliability and validity: The Composite

International Diagnostic Interview Andrews & Peters (1997) developed the CIDI to improve

the reliability and validity of the DSM.

This involves the client working through a structured interview either using a computer program or with an assistant.

They answer a range of questions on psychological disorders and their responses are used to determine which questions from the pool are asked or omitted.

If enough symptoms occur in patterns or clusters, then a diagnosis is made. All this is done by a computer program.

The Composite International Diagnostic Interview

A more acceptable method Patients feel more comfortable answering

questions on a computer It gave them the opportunity to reveal symptoms

they had never been asked before Less subjectiveHigh reliability and validity Research suggests that the CIDI is high in validity

and reliability

Evaluation: limitations There is a large amount of research supporting

the view that the reliability and validity of diagnosis are poor. This is due to many reasons, e.g. a possible social construction of mental illness, poor diagnostic tools, the possibility of faking, social influence, errors in attribution by practitioners and labeling

There are significant individual and cultural differences for the symptoms of mental disorders.

An individual may have multiple mental disorders

A wrong diagnosis may lead to a social stigma (an ethical issue)

Counter argument There are methodological problems with the studies on

validity and reliability (researcher bias, generalisability, ecological validity)

Revised diagnostic tools are higher in reliability than earlier versions, e.g. DSM-IV-TR

Many people do seek help voluntarily for disorders (which may mean that the disorder is valid)

The reliability of diagnosis is high for some disorders, e.g. obsessive compulsive disorder

There are many similarities of disorders across cultures Diagnostic systems do not classify people, but the

disorders that they have Alternative methods for diagnosis are being developed

all the time

Key Terms Test

Have a go at defining the following terms

Validity

Reliability

ICD

DSM

Diagnosis

Classification

Key Terms Reminder

Validity: this is the extent to which the diagnosis is accurate.

Reliability: this is how effective the use of a particular method of diagnosis (for example the DSM) is at identifying a disorder.

ICD: (International Classification of Diseases and Related Health Problems): The classification system for medical and mental health problems used by the World Health Organization (WHO).

DSM: (The Diagnostic and Statistical Manual of Mental Disorders): The classification and diagnosis system developed by the American Psychiatric Association (APA).

Diagnosis: is the process of identifying a medical condition or disease by its signs (what the physician sees), symptoms (what the patient says), and from the results of various diagnostic procedures.The conclusion reached through this process is called a diagnosis. Diagnosis is a clinical judgment on the part of the psychiatrist.

Classification: A list of disorders along with descriptions of symptoms and guidelines for making appropriate diagnosis (Comer, 2004). For example, deciding what schizophrenia is as apposed to depression.