Abnormal: How to discuss validity & reliability?

[Peachgon]

Hello, everyone.

The command term "discuss" wants us to provide arguments for and againts to give a balanced essay, but how do we apply this to a question such as "Discuss validity and reliability in diagnosis"? Do we assess the use of validity and reliability in the studies that we use, maybe?

All help appreciated!

[trishreddy]

I would start by doing something like this (except maybe a little bit more detailed - this is from ibpsychnotes)

Diagnosis

Purpose of diagnosis

• Identify abnormal disorders so treatment can be applied accordingly.
• Provides investigation opportunities into the etiologies of disorders.

Methods of diagnosis

• Biological tests
• Brain scans
• Blood tests
• Psychological tests
• IQ test
• Personality test
• Cognitive tasks
• Interviews
• Observations
• Reference to the Classification System (e.g. DSM, ICD)

Classification/Diagnosis systems

• Classification systems are suppose to be objective.
• Traditional medical model in psychiatry is now assumed to be reductionist.
• Most psychiatrists use a biopsychosocial approach in diagnosis and treatment.
• Diagnose based on symptoms.
• Affective (mood) symptoms
• Behavioural symptoms
• Cognitive (thought process) symptoms
• Somatic (physical) symptoms
• Based heavily upon abnormal experiences and belief reported by patients.
• Agreed by a team of professionals.
• Explains why Classification/Diagnosis systems are often updated and revised.

Strengths of classification systems

• Statistical diagnosis
• Quantifiable
• Ability to identify disorders based on symptoms
• Therefore suitable treatment can be applied

Weakness of classification systems

• Ethical consideration is the main weakness of Classification systems
• The effects of labeling
• Leads to stigmatisation
• Prejudice and discrimination
• Self labeling can lead to Self-fulfilling prophecy
• Person diagnosed with disorder act according to the label

Reliability

• Whether the same disorder is diagnosed every time.
• Inter-rater reliability: whether different diagnosticians get the same diagnosis. ie. how objective the diagnostic criteria is.
• Test-retest: whether repeating the diagnosis will give a different result between each time.

Then once I've done that I would then go into studies and then evaluate it (ethics and all that jazz) and then also relate it back to the question