Schizophrenia Flashcards
(58 cards)
Schizophrenia
A mental illness where contact with reality is impaired.
Classification systems of mental disorders
International Classification of Disease edition 10 (ICD-10)
Recognises different types.
Requires two negative symptoms.
American Association’s Diagnostic and Statistical Manual edition 5 (DSM-5)
Dropped sub-types.
Requires one positive symptom to be present.
Positive symptoms definition
Additional experiences beyond those of ordinary existence.
Positive Symptoms
Hallucinations
Delusions
Hallucinations
Unusual sensory experiences.
Some bear no relation to real events in the environment.
Some are related to what the senses are picking up from the environment/an extension to what is going on.
e.g. Hearing voices, see distorted facial expressions
Delusions
Irrational beliefs that take a range of forms.
Involves, being important historical, political or religious figures.
Mire likely to be victims of violence but some delusions can lead to aggression.
e.g. Thinking you’re as important as Jesus
Negative symptoms definition
Involve the loss of usual abilities and experiences.
Negative symptoms
Avolition
Speech poverty
Avolition
Find it difficult to keep up with goal orientated activities.
Poor hygiene, grooming, lack of persistence in work or education, lack of energy.
E.g. Keeping up with revision.
Speech poverty
Changes in patterns of speech.
A reduction in amount/quality of speech.
No logical structure and may have delays.
E.g. Changing topic, whistling, speaking, writing.
Subtypes of schizophrenia
Disorganised Catatonic Paranoid Undifferentiated Residual
Disorganised schizophrenia
Behaviour: disorganised, not goal directed.
Symptoms: thought disturbances, absence of expressed emotion, incoherent speech, mood swings, social withdrawal/loss of interest in life.
Diagnosed in adolescence/young adulthood.
Catatonic schizophrenia
Symptoms: severe motor abnormalities (unusual gestures or use of body language).
Repeated gestures that have meaning to them.
This type involves doing the opposite of what is asked or repeating everything that is said.
Main feature: almost total immobility for hours at a time with patient staring blankly.
Paranoid schizophrenia
Symptoms: delusions, emotionally responsive, more alert, argumentative.
Least serious, most well known. Later onset.
Undifferentiated schizophrenia
A broad category. Includes those who do not clearly fit into one category.
Show symptoms but do not fit into other types.
Residual schizophrenia
Those that have had an episode in the last 6 months and still exhibit some symptoms. These are not strong enough to merit putting them into other categories.
Mild symptoms.
Evaluation of diagnosis of schizophrenia
- Culture bias
Javier Escobar 2012: mostly white psychiatrists tend to over-interpret symptoms and distrust the honesty of black people in diagnosis. - Gender bias
Julia Longenecker et al 2010: reviewed studies of prevalence of schizophrenia and concluded since the 1980s men have been diagnosed with schizophrenia more often than women.
Evaluation of classification and diagnosis
+ classification systems provide a common language for practitioners
- reliability
Cheniaux et al 2009: 2 psychiatrists independently diagnose 100 patients using DSM and ICD criteria. 1: DSM 26/ ICD 44
2: DSM 13/ ICD 24
- validity
Cheniaux found more likely to be diagnosed using ICD
- co-morbidity
Having 2 illnesses together, so which symptoms for which illness.
- symptom overlap
Between schizophrenia and other illnesses (bipolar disorder: delusions, avolition)
Biological explanation of schizophrenia
Gottesman
Gottesman 1991
The closer related you are to someone with schizophrenia, the more likely you are to also have it.
Biological Evidence for schizophrenia
Family studies: Gottesman 1991: - could’ve been how you’ve been raised, similar situation to someone with schizophrenia.
Twin studies: Joseph 2004: concordance rate 40.4% MZ and 7.4% DZ so inherited by genes : - MZ more similar environment? Share more nurture too, so high concordance rate due to nurture?
Adoption studies: Tienari 2000: 6.7% children’s mum who had it got it/ 2% who’s mother didn’t, got it: - individual differences, sime stay in similar situation i.e. Adopted by grandparents. Also age adopted?
Ripke 2014: huge study of data of genome = 108 genes implicated
The dopamine hypothesis
Hyperdopaminergia in subcortex: too much dopamine.
High levels or activity in central brain and mesolimbic pathway.
E.g. Too much dopamine D2 receptors in Broca’s area can lead to speech poverty/auditory hallucinations.
Hypodopaminegia in cortex: Goldman-Rakic et al 2004: found low levels or activity in prefrontal cortex (thinking and decision making) and mesocortical pathway in patients with negative symptoms of schizophrenia.
Evaluation of dopamine hypothesis
Dopamine agonists: inc level of dopamine and make symptoms worse. Curran et al 2004. E.g. Cocaine exaggerates positive symptoms in people who have schizophrenia.
Dopamine antagonists: anti-psychotic drugs reduce levels of dopamine and can eliminate hallucinations and delusions. Tauscher et al 2014.
- Ripke 2014: 108 genes implicated, not all connected to dopamine, other neurotransmitters.
Neural correlates
Measurements of the structure or function of the brain that correlate with an experience (schizophrenia).
Both positive and negative symptoms have correlates.
Neural correlates of negative symptoms
Activity in ventral striatum has been linked to development of avolition.
Ventral striatum has been linked to anticipation of rewards.
Therefore, abnormality in ventral striatum = lack of motivation (avolition).
