© Hodder & Stoughton 2013

Abnormal psychology

Concepts and diagnosis

© Hodder & Stoughton 2013

Activity

Abnormality can be defined as ‘a psychological or behavioural state leading to impairment of interpersonal functioning and/or distress to others’.

• Imagine someone with a plastic duck on their head.

• Would you consider this person to be abnormal or not?

• Would it matter what age or gender they were? What their cultural background was? What situation this behaviour was occurring in?

© Hodder & Stoughton 2013

Defining abnormality• The deviation from social norms

definition sees abnormality as behaviour that violates accepted social rules, with these ‘rules’ changing across cultures, genders, ages, situations etc.

• The failure to function adequately definition sees abnormality as an inability to cope with day-to-day living and focuses upon personal distress, inappropriate behaviour, unpredictability, irrationality, observer discomfort, violation of moral standards and unconventionality.

• The deviation from ideal mental health definition sees abnormality as a failure to meet criteria for perfect psychological well-being, such as positive self-attitude, realizing one’s potential, being independent, resisting stress, perceiving reality and control over one’s environment.

Read these three definitions of abnormality and see if you can use them to decide whether a person with a plastic duck on their head is abnormal or not. Is any one definition better than the others?

© Hodder & Stoughton 2013

Command words: The language of the learning outcomes

• Exam questions will require candidates to consider what abnormality is in relation to different definitions and biological/psychological approaches.

• This could be achieved by exploring the assumptions and criteria that the different definitions and approaches are based upon.

Learning outcome: Examine the concepts of normality and abnormality

© Hodder & Stoughton 2013

Reliability and validity of diagnosis

Reliability

• Reliability of diagnosis refers to the consistency of symptom measurement.

• Reliability affects classification of diagnosis in two ways:

1. Test-re-test reliability – occurs when a clinician makes the same consistent diagnosis on separate occasions using the same information.

2. Inter-rater reliability – occurs when several clinicians make identical diagnoses of the same patient, independently of each other.

Validity

• Validity refers to the accuracy, meaningfulness and usefulness of diagnosis.

• Validity is assessed in four ways:

1. Reliability – a valid diagnosis must first be reliable.

2. Predictive validity – diagnosis leading to successful treatment is seen as valid.

3. Descriptive validity – patients diagnosed with different disorders, differ from each other in terms of classification.

4. Aetiological validity – patients diagnosed with the same disorder, have the same cause.

© Hodder & Stoughton 2013

Command words: The language of the learning outcomes

• Exam questions will require candidates to describe and evaluate reliability and validity of diagnosis.

• This could be achieved by outlining the concepts of reliability and validity in how they apply to diagnosis, as well as using research evidence to assess the degree to which diagnosis of mental disorders is reliable and valid.

• Additional material relating to the reliability and validity of diagnosis could also be incorporated, such as how reliability and validity of diagnosis have changed over time, the development of specialist diagnostic inventories and the reliability and validity of diagnosis of different mental disorders.

Learning outcome: Discuss validity and reliability of diagnosis

© Hodder & Stoughton 2013

Cultural considerations in diagnosis

The incidence of schizophrenia in the Caribbean is the same as the rest of the world, 1%, yet Cochrane (1977) found that black people of Caribbean origin in the UK are up to 7 times more likely to be diagnosed as schizophrenic than native white people in the UK.

How might the findings of Cochrane’s study be explained?

Consider:

1. Social stressors, such as poor housing, low socio-economic status, racism etc.

2. Cultural relativism: where definitions of abnormality vary between cultures.

3. The fact that clinicians who make diagnoses in the UK tend to be white.