Neuroscience and Clinical Semester 1 Week 6: Classification and Assessment in Clinical Psychology Flashcards
Goals of classification and diagnosis
- understand causes
- identify most appropriate treatment
- determine if treatment has been effective
- practical consequences (e.g. are they fit to stand trial, do they deserve compensation etc.)
Objectives of classification systems
1) Provide necessary and sufficient diagnostic criteria for correct differential diagnosis (enough info to differentiate between disorders)
2) Permit distinction of ‘true’ psychopathology from non-disordered ‘problems in living’
3) Diagnostic criteria can be systematically applied, by different clinicians in different settings.
4) Diagnostic criteria should be theoretically neutral (focus on symptoms not theories about causes)
DSM-5 diagnostic criteria for Generalised Anxiety Disorder
- Excessive anxiety and worry for at least 6 months
- Worry is difficult to control
- Anxiety and worry associated with at least 3 of the following:
o Restlessness
o Easily fatigued
o Difficulty concentrating
o Irritability
o Muscle tension
o Sleep disturbance - Clinically significant distress or impairment
- Not attributable to any substance or other medical condition
- Not better explained by another psychological disorder
ICD-10 diagnostic criteria for Generalised Anxiety Disorder
- Prominent tension, worry, and feelings of apprehension for at least 6 months
- At least four of the following symptoms, one of which must be from 1.
o Palpitations or pounding heart; sweating; trembling or shaking; dry mouth
o Difficulty breathing; feeling of choking; chest pain or discomfort; nausea; feeling dizzy or lightheaded; derealization; depersonalization; fear of losing control, going crazy, or passing out.
What is a taxonomic approach?
- both manuals take a taxonomic approach
- systematically organising and categorising mental disorders based on specific criteria - making categories
E.g.
o Anxiety disorders: panic disorder, generalised anxiety disorder, and specific phobias etc.
o Depressive disorders: major depressive disorder, persistent depressive disorder etc.
Problems of diagnostic manuals
1) Describe observable symptoms rather than explain causes
2) Diagnoses (labels) can be stigmatising
3) Diagnoses are categorical - they have it or don’t have it
4) Homogeneity of sufferers - many different combinations could warrant a diagnosis of something and yet required treatment may be very different
5) Disorders are distinct from each other and yet comorbidity is the norm
6) A large collection of disorders with lots of historical biases - e.g. is it a lifelong or temporary condition
Some specific criticisms of DSM-5
- Proliferation of disorders with each revision (always increasing)
- Gradual lowering of thresholds
favours over- rather than under-diagnosis, ‘medicalising’ normal experiences and overprescription of psychiatric medication. - Disproportionately influenced by biological models
- Most psychological disorders are dimensional, i.e. they have a continuum of severity
DSM 5 does explicitly acknowledge this but it still requires a threshold which is therefore somewhat arbitrary and subjective
Types of reliability
- Test-retest reliability:
The extent to which a test will produce roughly similar results when a test is given to the same person several weeks/months apart - Inter-rater reliability:
The degree to which two independent clinicians agree when interpreting or scoring a particular test - Internal consistency:
The extent to which all items in a test measure the same concept
Types of validity
- Concurent validity:
A measure of how highly correlated scores of one test are with scores from other types of assessment that we know also measure that attribute - Predictive validity:
The degree to which an assessment method is able to help the clinician predict future behaviour and / or symptoms - Construct validity:
The degree to which an assessment tool measures what it is intended to measure - Face validity:
The extent to which a test appears to measure what it is supposed to measure
Methods of assessment
- Clinical interviews
- Clinical observation
- Psychological tests:
o Questionnaires
o Projective tests
o Intelligence tests - Biologically based assessments
o Psychophysiology
o Neuroimaging
Clinical interviews
- Structured or unstructured
- Structured clinical interview for DSM (SCID)
- Predetermined questions, responses determine the next question
- High inter-rater reliability
Limitations of clinical interviews
- Reliability of unstructured interviews is low - different skill levels of clinicians
- Some disorders characterised by poor self-awareness
- Some clients may intentionally mislead (e.g. some personality disorders)
- Interviewers prone to biases (e.g. primacy effect) - may jump to conclusions based on what symptoms you first report
Clinical observation
- Systematically observing behaviour e.g. ABC model (Antecedents, behaviour, consequence)
- Captures frequency of target behaviours
- Identifies practical treatment
- Better ecological validity than self-reports
Limitations of clinical observation
- Very time-consuming, observers need a lot of training
- Observations normally limited to one context
- Presence of observer may influence behaviour
- Inter-observer reliability can be poor unless both are intensively trained
Questionnaires
- Rigid response requirements so objective
- Good internal reliability and concurrent validity
- Can establish statistical norms
