#8723 - Clinical Psychology - Edexcel Psychology

Clinical psychology

Definition of the application

• Clinical psychology is the study of mental health and well-being and includes the study of mental health conditions and disorders.

• Clinical psychology aims to classify and diagnose, explain and treat mental health conditions or disorders, to reduce psychological distress and enhance and promote psychological well-being.

• Clinical psychologist work in a range of settings including hospitals, health centres, community mental health teams, child and adolescent mental health services (CAMHS) and social services. They work with children and adults with mental and physical health problems, including anxiety, depression, relationship problems and addictions.

• They undertake clinical needs assessments using psychometric tests, interviews and direct observations of behaviour. They deliver and evaluate the effectiveness of therapy, counselling and advice.

• Clinical psychologists often work as part of a team with, social workers, medical practitioners and other health professionals. Most of them work for the National Health Service, which has clearly defined career structure, but some work in private practice.

• The work is often directly with people, both individually or in groups, assessing their needs and providing therapies based on psychological theories and research. Some clinical psychologists also work as trainers, teachers and researchers at universities.

How science works

Primary and secondary data

Primary data

• Collected first hand by the researcher for a specific research purpose. It can be qualitative or quantitative.

• An example of qualitative primary data is Brown et al. 1986 who interviews pps and information was collected about self-esteem, life events and perceived social support over the course of the longitudinal study.

• An example of quantitative primary data was encountered in Castner et al. (1998) where a study of rhesus monkeys later exposed whilst in the uterus to radiation to see whether this led to symptoms of schizophrenia later in life; here the monkeys were observed for signs of hallucinations (a nominal scoring system was used such as a tally chart).

• The monkeys were also given cognitive tests to see whether exposure to radiation led to disordered thinking. These tests would have led to ratio data in the form of scores on a standardised psychological tests and this is also a form of primary data collection.

Secondary data

• This means that someone else has already collected the information, for a different purpose and the information have been stored on record for use by other researchers. The researcher will re-analyse this second hand data for a new purpose.

• Results of psychological studies are classed as secondary data and often a researcher will conduct an in-depth review of the data in the area of interest before embarking on his or her own primary data collection.

• In clinical psychology, secondary data might include medical records made by doctors including diagnosis of disorders or how a patient has responded to treatment options. It could also include school reports which provide insight into an individual's life before the onset of a disorder.

• A specific example of the use of secondary data in clinical psychology was Gottesman and Shields (1966) use of pre-existing diagnoses of schizophrenia and other psychiatric disorders in their twin pairs from Bethlem and Maudsley hospital.

Using both types of data

Gottesman and Shields (1966) used both types of data in their study to see if schizophrenia is inherited. First, they found out the mental health of pairs of identical and non-identical twins by accessing hospital records for twin where at least one of the pair had been diagnosed with a mental disorder. This was using secondary data. They then interviewed the twins, as adults, to assess their mental health and to find out the course of their mental disorder. When interviewing they were gathering primary data. They gathered quite a lot of information about the twins and then drew conclusions about how often when at least one twin had schizophrenia or some related disorder; the other had been diagnosed with it as well.

Evaluation of primary and secondary data

Primary strengths

• Gathered of intended purpose therefor likely to be more focused on that purpose, secondary data taken from another source and have often been gathered for a different reason. E.g. Gottesman and shields (1966) had to discount some of their pairs of twins because they could not be sure whether they were monozygotic or dizygotic twins, which affected their study.

• Primary data tends to be more valid in that they are gathered first hand and any operationalizing is done carefully with the purpose in mind so the data are more likely to represent real life. Secondary data if they are statistics from surveys, which they often are might not be valid if used as if they are about individuals. However if the secondary data was originally primary data from another study, then they might well have been gathered validly.

• Primary data is more likely to have credibility as they are gathered for a specific purpose and analysed with that purpose in mind. Secondary data are likely to have been gathered with one purpose in mind and when used in a 'secondary' fashion they may not be seen to have credibility.

• Primary data are analysed directly by the researchers, whereas secondary data may already have been analysed, which can bring in an element of subjectivity. However, secondary data can be 'raw' data and not previously analysed.

• Primary data are gathered at the time of the study, whereas secondary data is likely to be gathered some time previously, which mean primary data are more likely to be valid in the sense of being up to date.

Secondary strengths

• Secondary data are cheaper because they are already there. Primary data tend to be expensive because the study has to be run completely, including finding the pps, developing the research method and setting up any situation or survey.

• Secondary data can involve more pps, such as in meta-analysis, so the range of pps can be wider and generalizability can be improved. This is not always the case but in studies such as craft et al. (2003), where they used data from many studies that used the same questionnaire, they had a lot more data than if they gathered the information first hand. Studies gathering primary data are often limited in the number if people they involve.

• Secondary data tends to consist of more data too, although again this is not always the case. E.g. Gottesman and Shield (1966). By using the hospital records over a number of years were able to access a lot of detail about pairs of twins that otherwise would have been hard, if not impossible, to put together p. when gathering primary data it is often the case that the numbers that can be involved are limited, either by cost or to make the study manageable, or both.

Reliability and validity

Reliability

• Reliability refers to the consistency with which a measure of psychological variable identifies the same thing.

• A diagnosis of mental disorder is considered reliable if more than one psychologist gives the same diagnosis to the same Individuals, therefore the diagnosis is consistent. This is known as inter-rather reliability.

• For example, in Rosenhan's (1973) each of the pseudo patients reported the exact same symptoms and in 7 out of 8 cases, the same diagnosis was applied, (schizophrenia) suggesting reliability, if not validity in diagnosis.

• Reliability can also be assessed by seeing whether the same individual is given the same diagnosis when assessed at several intervals. This is called test-retest reliability.

• This is often measured using PPVs (positive predictive value) which is basically a percentage which tells us the percentage of people who keep the same diagnosis over time.

• Cohen's kappa in another figure used when talking about reliability of diagnosis; this is a decimal which again shows the proportion of people who keep the same diagnosis.

Validity

• Validity refers to the extent to which a measure of a psychological variable measures what it sets out to measure and that the measurement is not simply a reflection of the testing situation but of the persons behaviour, thinking and emotions more generally, in their everyday life.

• With regard to the diagnosis of mental disorders, the DSM IV TR and other diagnostic systems such as the ICD 10 operationalize mental disorders using lists of symptoms, however some psychologists feel that these lists do not have construct validity; that when symptoms are similar across different disorders, then validity of diagnosis is limited in It is possible that the distinctions made between disorders are false.

• Secondly psychologists argue about the predictive validity of the various diagnoses; if a person is given a certain diagnosis, then this should successfully predict that they will experience relief if given a known treatment for this particular disorder and that people given this diagnosis will respond to the treatments in similar ways.

• Finally a diagnosis can be said to have concurrent validity if the individual is assessed using two or more different techniques and the same disorder is identifies using each technique, for example self-rating, family or teacher observations and psychological testing.

Definition of schizophrenia

• Schizophrenia is a psychotic condition that affects approximately 1% of people at some point in their lives worldwide

• It affects the same number of males and females but the age of onset is earlier...