Schizophrenia Flashcards
(44 cards)
What is Schizophrenia?
A mental disorder characterised by psychosis. Patients find it difficult to distinguish between reality and their own thoughts.
Positive symptoms:
Are an excess or distortion of normal experiences. They are in addition to your ordinary experiences:
Hallucination - Distorted sensory experiences. Can be related to any senses but most common ones are auditory or visual.
Delusions - A belief or thought that is untrue or irrational. (Paranoia)
Negative Symptoms:
These are symptoms that are a loss of normal functions and experiences:
Speech poverty - Speech becomes lessened/disorganised. Difficult to form a sentence.
Avolition - This is apathy towards achieving goals. Patients suffer a lack of motivation characterised by poor hygiene, lack of persistence in work & lack of energy.
Diagnosis of Schizo:
Can be done through:
ICD - 10/11 Classification system - Requires 2 or more negative symptoms for diagnosis.
DSM - V Classification System - Requires one positive symptom for diagnosis.
Reliability for Schizo:
Inter-rater Reliability - refers to the extent that 2 clinicians will reach the same diagnosis.
Test-retest reliability is whether the same diagnosis is reached for the same individual on 2 occasions by one clinician.
Overall, reliability has been low, however recent studies suggest higher.
Osario et al (2019) - found I-RR of +97 & T-RR of +92.
Validity for Schizo:
Validity refers to the extent that a diagnosis represents something that is real and distinct from other disorders and whether the ICD and DSM measure what they claim to measure.
Cheniaux et al (2009) found that when two psychiatrists assessed the same client both using ICD and DSM that 68 were diagnosed with the ICD and only 39 under the DSM.
SO depending on the system used, Shizo may be over or under diagnosed.
Factors affecting Reliability and Validity:
Co-Morbidity
Gender Bias
Symptom Overlap
Culture Bias
Co-Morbidity
Extent to which 2 or more conditions occur at the same time in a patient:
Buckley et al - Sz is often diagnosed alongside
50% depression
47% Substance abuse
23% OCD
Makes diagnosis and treatment of Sz more difficult and can even argue that it may not be a distinct disorder.
Symptom Overlap
Symptoms of Sz are also symptoms for other disorders e.g - Bipolar disorder.
Therefore, it could be that they are not separate conditions but different variations of the same condition.
Gender Bias
Cotton et al (2009) - More men are diagnosed than women this could be because women have more social support and so function better.
Leads to underdiagnosis and a lack of treatment for women.
Culture Bias:
Symptoms can be interpreted differently in different cultures.
African - Caribbean British people are 9x more likely to be diagnosed than White British people.
Genetic Explanations
Family Studies
Candidate genes
Mutation
Family Studies
If one member has Sz then the chance of another family member also being diagnosed with it increases as they become more genetically similar.
Gottsman (1991) - found that Mz have a 48% CCR, Dz have a 17% and parents have 6%. This is in comparison to the general population which is only 1%.
Candidate genes
Sz appears to be polygenic in that a combination of different genes may cause it. It is believed that genes responsible for coding dopamine NT are most likely to be involved.
Mutation
Even if there is no family history of Sz, it could be caused by a mutated gene of a parent through radiation, viral infection or poisoning.
AO3 for Genetic Explanations
Environment - The fact that the CCR for twins is not 100% means that Sz cannot be accounted for by genetics alone. E.g - Morkved et al (2017) found that 67% of patients had experienced childhood trauma.
Diagnostic Criteria - Cardno et al (1999) used the “Maudsley Twin Register” which uses strict diagnostic criteria and found a CCR of 26.5% for Mz and 0% for Dz twins. We cannot compare studies using different criterias.
Adoption Studies - Hiker et al (2018) found a CCR of 33% for Mz and 7% for Dz twins even though they were adopted, suggesting a genetic basis.
Neural Explanations for Sz
Dopamine Hypothesis
Ventral Striatum
Superior Temporal Gyrus and Anterior Cingulate Gyrus
Dopamine Hypothesis
Hyperdopaminergia - Excess levels of dopamine receptors in the pathway from the subcortex to the Broca’s area, causing speech poverty/auditory hallucinations.
Hypodopaminergia - Low levels of dopamine in the prefrontal cortex causing problems with thinking and decision making (negative symptoms).
Ventral Striatum
This is used in the anticipation of reward.
Juckel et al (2006) measured the activity levels and found lower level of activity in Sz patients compared to controls.
Superior Temporal Gyrus & Anterior Cingulate Gyrus
Reduced activity in these parts of the brain is a neural correlate for auditory hallucinations.
AO3 For Neural Explanations for Sz
Drug Therapy - Antipsychotics reduce symptoms by reducing dopamine and amphetamines worsen symptoms as they increase dopamine. This gives evidence for the dopamine hypothesis.
Glutamate - McCtcheon et al (2020) found that Sz patients have a deficiency in a glutamate function, which could have a more important role in Sz symptoms.
Correlations - No correlations with brain areas to imply causation. Studies cannot explain why these areas have HIgher or lower activity.
Family Dysfunction
Schizophregenic Mother
Double-Bind Theory
Expressed Emotion (EE)
Schizophregenic Mother
Fromm-Reichmanns (1948) - Psychodynamic explanation explains that a mother who is cold, rejecting & controlling can cause Sz in her child. She creates an environment of tension and secrecy, which leads to the childs distrust and later develops into paranoid delusions.
Double-Bind Theory
Children who receive contradictory messages from their parents are more likely to develop Sz, as they fear doing the wrong thing by get mixed messages about what this i. They find this confusing and cause symptoms like disorganised thinking and paranoid delusions.
