Schizophrenia Flashcards
What are the diagnostic tools used to diagnose Schizophrenia?
ICD-11 and DSM-V
What are positive and negative symptoms?
Positive symptoms are additions to normal behaviour and negative symptoms are absences of normal behaviour
What are hallucinations?
Unreal perceptions of the environment
What are the types of hallucinations? Give an example for each.
Auditory- e.g. hearing voices
Visual- e.g. lights, objects or faces
Olfactory- e.g. smelling things
Tactile- e.g. feeling of bugs crawling on or under the skin
What are delusions?
Bizarre beliefs that seem real to the person with Schizophrenia, but they are not real. Sometimes these beliefs can be paranoid, such as delusions of persecution and sometimes they involve themselves such as delusions of grandeur
What is disorganised thinking?
The feeling that thoughts have been inserted or withdrawn from the mind. In some cases, the person may believe their thoughts are being broadcast so others can hear them.
What is catatonic behaviour? Is it a positive or negative symptom?
Catatonic behaviour refers to bizarre and abnormal motor movements. For example, holding the body in a rigid stance, moving in a frenzied way, peculiar facial movements or copying movements of others. It can be either a negative or positive symptom- sometimes individuals might slow down and sometimes they may speed up
What is affective flattening?
A reduction in the range and intensity of emotional expression, including facial expression, voice tone, eye contact and body language
What is alogia (poverty of speech)?
This is characterised by the lessening of speech fluency and productivity; thought to reflect slowing or blocked thoughts
What is social/ occupational dysfunction?
Occurs when one or more major areas of functioning such as work, interpersonal relations or self-care is markedly below the level achieved prior to the onset for a significant portion of time since the onset
What is avolition?
The reduction of or inability and persistance in goal-directed behaviour, for example sitting in the house for hours every day, doing nothing
What is anhedonia?
A loss of interest or pleasure in almost all activities, or lack of reactivity to normally pleasurable stimuli
In the current edition of DSM-V, what needs to be present for a Schizophrenia diagnosis?
Criterion A- 2 or more symptoms present
Criterion B- Social/ occupational dysfunction
Criterion C- positive symptoms consistently for a month prior to diagnosis
What is the one symptom that can diagnose Schizophrenia on its own?
If hallucinations/ delusions are very bizarre or voices are conversing or holding a running conversation then Schizphrenia can be diagnoses with just this 1 symptom
What is the reliability of diagnosis?
If a diagnosis is reliable it means that clinicians must reach the same conclusions at two different points in time (test-retest) or different clinicians must reach the same conclusion (inter-rater reliability)
How is inter-rater reliability measured?
By a statistic called a Kappa score. A score of 1 indicates perfect inter-rater agreement and a score of 0 indicates zero agreement. A Kappa score of 0.7 is generally considered good
Outline a study that shows cultural differences in diagnosis (reliability problems)
- Copeland
- 134 US and 194 British psychiatrists given description of a patient
- 69% of the US psychiatrists diagnosed schizophrenia but only 2% of the British ones gave the same diagnosis
What is validity in terms of diagnosing Schizophrenia?
Refers to the extent that a diagnosis represents something that is real and distinct from other disorders.
The extent to which a system such as DSM-V is measuring what it intends to measure
Explain how gender bias affects the validity of a Schizophrenia diagnosis
- Critics of DSM diagnostic criteria argue that some disagnostic categories are biased towards one gender
- Broverman et al found that clinicians in the US equated mentally healthy ‘adult’ behaviour with mentally healthy ‘male’ behaviour
- As a result there was a tendency for women to be perceived as less mentally healthy
What is symptom overlap?
Refers to the fact that symptoms of a disorder may not be unique to that disorder but may also be found in other disorders, making accurate diagnosis difficult
Outline a study which shows the effects of symptom overlap
- Ellason and Ross
- Found that patients with dissociative identity disorder (DID) had more Schizphrenia symptoms than patients diagnosed with Schizophrenia
What is co-morbidity?
Refers to the extent that two (or more) conditions or diseases occur simultaneously in a patient, for example schizophrenia and depression
Outline a study of co-morbidity
- Buckley et al
- Found that co-morbid depression occurs in 50% of patients
- 47% patients also have a lifetime diagnosis of co-morbid substance abuse
Give two evaluation points for validity in diagnosis and classification of Schizophrenia
Research support for gender bias- Loring and Powell presented 290 psychiatrists with a patient description. They found that when the patient was described as male or no information given about gender, 56% of the psychiatrists gave the schizophrenia diagnosis but when the patient was described as female only 20% were diagnosed with Schizophrenia
Consequences of co-morbidity- studies found many patients with a primary diagnosis of schizophrenia were also diagnosed with medical problems such as asthma, hypertension and type 2 diabetes. They found that the very nature of a diagnosis of a psychiatric disorder means patients receive a lower standard of care which will affect their Schizophrenia diagnosis
Give two evaluation points for reliability in diagnosis and classification of Schizphrenia
Lack of inter-rater reliability- Whaley found inter-rater reliability correlations in diagnosis of Schizophrenia as low as 0.11
Unreliable symptoms- one of the characteristic symptoms for diagnosing Schizophrenia is “bizarre delusions” but when 50 senior psychiatrists were asked to differentiate between bizarre and non-bizarre delusions, their inter-rater reliability correlations were only 0.40 which shows that even this central diagnostic requirement lacks sufficient reliability.
Describe a family study of Schizophrenia
- Gottesman
- Found individuals with Schizophrenia and aimed to determine whether their biological relatives are similarly affected
- Found that Schizophrenia is more common among biological relatives and that the risk increases with genetic closeness
- Children with two Schizophrenic parents had a concordance rate of 46% and children with one schizophrenic parent had a concordance rate of 13%
Describe a twin study of Schizophrenia
- Joseph
- Found a concordance rate of 40.4% for M/Z twins and 7.4% for DZ twins
- This supports a genetic position