2.) Discuss validity and reliability of diagnosis.
This question is a bit tricky, but overall it makes an easy choice on the test. Before you jump in to validity and reliability, you have to look at what a diagnosis is and how it can be made. Don't worry, it's all in the outline below!
I. Intro – Ways to diagnose psychological disorders
- ex. interviews, brain-scanning techniques, personality tests
- subjective and objective methods
II. Things that can affect diagnosis – patient anxiety, clinician’s treatment style or experience
III. Different kinds of symptoms – the ABCS of diagnosis
- Affective symptoms – emotional elements, ex. fear, sadness
- Behavioral symptoms – observed behaviors, ex. crying, pacing
- Cognitive symptoms – ways of thinking, ex. pessimism, self-image
- Somatic symptoms – physical symptoms, ex. facial twitching, amenorrhea
IV. Define reliability and validity
- Reliability of a study - the ability for two different psychologists to diagnose the same patient with the same disorder
- Validity - the possibility to observe a group of symptoms, correctly diagnose a disorder and provide respective treatment
V. Use of different classification systems means different rates –
- The DSM-IV has been rated overall to be 64% reliable
- This contrasts with the classification system of Great Ormond Street Children’s Hospital in London, who has a reliability rate of 88%
VI. Rosenhan (1973) –
Purpose: Undermines the idea of correct diagnosis – Study: Rosenhan had confederates pretend to be inflicted with schizophrenia and enter a mental facility. All were immediately diagnosed with schizophrenia, with only two employees expressing doubt at the diagnoses. Also said some pseudo-patients would enter the next week, but really none did, although 41 patients were suspected as faking their illness. An example of conformation bias - because the patients were expected to have schizophrenia, they were diagnosed with it.
VII. Beck et. Al (1972) –
Purpose: Shows the potential problems of maintaining reliability in a system - Study: Two psychiatrists diagnosed the same 153 patients, but only agreed on the same disorder 54% of the time.
- ex. interviews, brain-scanning techniques, personality tests
- subjective and objective methods
II. Things that can affect diagnosis – patient anxiety, clinician’s treatment style or experience
III. Different kinds of symptoms – the ABCS of diagnosis
- Affective symptoms – emotional elements, ex. fear, sadness
- Behavioral symptoms – observed behaviors, ex. crying, pacing
- Cognitive symptoms – ways of thinking, ex. pessimism, self-image
- Somatic symptoms – physical symptoms, ex. facial twitching, amenorrhea
IV. Define reliability and validity
- Reliability of a study - the ability for two different psychologists to diagnose the same patient with the same disorder
- Validity - the possibility to observe a group of symptoms, correctly diagnose a disorder and provide respective treatment
V. Use of different classification systems means different rates –
- The DSM-IV has been rated overall to be 64% reliable
- This contrasts with the classification system of Great Ormond Street Children’s Hospital in London, who has a reliability rate of 88%
VI. Rosenhan (1973) –
Purpose: Undermines the idea of correct diagnosis – Study: Rosenhan had confederates pretend to be inflicted with schizophrenia and enter a mental facility. All were immediately diagnosed with schizophrenia, with only two employees expressing doubt at the diagnoses. Also said some pseudo-patients would enter the next week, but really none did, although 41 patients were suspected as faking their illness. An example of conformation bias - because the patients were expected to have schizophrenia, they were diagnosed with it.
VII. Beck et. Al (1972) –
Purpose: Shows the potential problems of maintaining reliability in a system - Study: Two psychiatrists diagnosed the same 153 patients, but only agreed on the same disorder 54% of the time.