Schizophrenia

Schizophrenia

1. Classification

   • Positive symptoms
     • Hallucinations
     • Delusions
     • Speech disorganisation
   • Negative symptoms
     • Avolition
     • Speech poverty
   • Reliability and validity
     • Validity
       • Extent to which we are measuring what we intend to measure (accuracy)
         • Rosenhan (1973): 8 volunteers without Sz went to various psychiatric hospitals claiming they heard voices -> suggests doctors did not have valid method for diagnosis
     • Reliability
       • If same conclusion is drawn about a diagnosis from different clinicians (consistency)
         • Cheniaux et al (2009): two psychiatrists evaluated 100 patients, psychiatrist 1 found 26 schizophrenic patients with DSM criteria and 44 with ICD. Whereas psychiatrist 2 found 13 patients with DSM and only 24 with ICD.
           • Suggets both low inter-observer reliability and low reliability between the two classification systems
     • Causes of issues
       • Co-morbidity (RELIABILITY)
         • The occurrence of two illnesses or conditions together
           • Goldman (1999) reported that 50% of schizophrenics had another medical condition such as substance abuse.
       • Symptom overlap (VALIDITY)
         • Schizophrenia shares symptoms with other psychological disorders, such as depression and autism
           • For example, both people with schizophrenia and people with autism often suffer with speech poverty.
             • Hewitt (2001): compared 14 autistic patients with 14 schizophrenia patients -> 7 of the autistic patients had symptoms of schizophrenia.
       • Gender bias (VALIDITY)
         • A view that does not justifiably represent the experience of men or women.
           • Aleman et al (2003): meta-analysis found men were 42% more likely to suffer from schizophrenia than women
       • Culture bias (VALIDITY)
         • A tendency to ignore cultural differences and interpret all phenomena through the “lens” of one’s own culture.
           • Escobar (2012): has pointed out that White psychiatrists may tend to over-interpret the symptoms of Black people during diagnosis.
   • Diagnosing
     • DSM-5
       • 1 of the positive symptoms must be present
     • ICD-10
       • 2 or more positive symptoms must be present (but only 1 is needed if delusions arte bizarre or if hallucinations consist of a voice commenting on individual's behaviour

2. Biological explanations

   • Genetics (hereditary factors)
     • Twin studies
       • MZ twins share 100% of DNA so if explanation is down to genetics, condition would be equally common to identical twins
         • Gottesman (1991): MZ twins have concordance rate of 48% but only 17% for DZ twins
           • However, twin studies can be impacted by environmental factors too because when twins look identical, they are likely to be treated similarly by people -> contributing to higher concordance rate
       • Polygenic = number of genes make us vulnerable Aetiologically heterogeneous = can result from a combination of several causes
         • Ripke et al. (2014): found 108 different genetic variations correlated with schizophrenia
           • Biologically reductionist - oversimplifies a complex behaviour to the action of genetics: schizophrenia is difficult to describe
       • Tienari et al (2004): children adopted from 19,000 Finnish mothers with Sz - it was found that genetically vulnerable children combined with critical, conflict-based child-rearing practices were the most likely to develop Sz
   • Neural correlates
     • Enlarged ventricles
       • Andreasen et (1990) – conducted a very well controlled CAT scan study and found significant enlargement of the ventricles in schizophrenia patients compared to controls. However, this was only the case of men, and not women.
     • Negative symptoms
       • Avolition has been related to the ventral striatum
         • Juckel et al (2006) found that there were lower levels of activity in the ventral striatum in schizophrenia compared to controls, and that there was a negative correlation between activity levels in the ventral striatum and the severity of negative symptoms.
     • Positive symptoms
       • Allen et al (2007) scanned the brain of people experiencing auditory hallucinations and compared them to a control group whilst they identified pre-recorded speech as theirs or other people’s. The scans found lower activation levels in the superior temporal gyrus and anterior cingulate gyrus in the hallucination group, who also made more errors than the control group.
     • Dopamine hypothesis
       • Suggests that levels of the neurotransmitter dopamine in certain parts of the brain is largely related to the symptoms too
         • Hypodopaminergia in the cortex FOLLOWED BY Hyperdopaminergia in the subcortex
           • Davis et al (2011): schizophrenia is characterized by abnormally low prefrontal dopamine activity (causing negative symptoms) leading to excessive dopamine activity in subcortical dopamine neurons (causing positive symptoms)
         • Iversen (1979): reported that post-mortems on people who had schizophrenia found excess dopamine in the limbic system
     • Biologically deterministic (little free will)
     • Biologically reductionist (oversimplifies complex behaviour)
     • Practical applications; anti-psychotic medication influences dopamine to reduce Sz symptoms

3. Psychological explanations

   • Dysfunctional thought processes (cognitive)
     • Frith et al. (1992)
       • Meta-representation
         • Refers to ability to be able to reflect on thoughts/behaviours and enables us to insight into our own intentions -> leading to hallucinations and delusions
           • Sz auditory hallucinations are just misinterpretations of subvocal speech (patients own voices is misinterpreted as external phenomenon)
             • Bick and Kinsboure (1987): when patients opened mouths (which prevents subvocal speech), they reported that auditory hallucinations stopped
       • Central control
         • Refers to the cognitive ability to suppress automatic responses while we perform deliberate actions instead -> leading to disorganised speech
           • Stirling et al (2006): used Stroop Test (patients had to name ink colours rather than reading words themselves). This involves suppressing automatic thoughts and Sz group took twice as long than control
   • Family dysfunction (abnormal processes within family)
     • Schizophrenogenic mother
       • Psychodynamic explanation for Sz
       • Mothers were cold, rejecting and controlling + created family climate characterised with tension and secrecy
         • Leads to distrust within family -> later causing paranoid delusions
       • Lack of evidence to directly support schizophrenogenic mother or double bind
       • Socially sensitive research: parent-blaming adds insult to injury
     • Double bind
       • (Bateson et al 1972) Sz patients find themselves in situations where they fear doing the wrong thing but receive mixed messages about what the right thing/wrong thing is
         • When they get it wrong, they are punished by withdrawal of love -> makes world seem confusing/dangerous and leads to paranoid delusions
         • NOTE: Bateson noted that this was not only reason someone might develop schizophrenia but rather just potential risk factor
       • Berger (1965): Sz patients reported higher recall of double-bind statements by their mothers than non-schizophrenics
         • However, patients' recall may be affected by Sz e.g. delusions may distort their memories
     • Expressed emotions
       • Includes critical comments, hostility towards patient and emotional over-involvement in life of patient (i.e. needless self-sacrifice)
         • Can increase risk of relapse or even trigger Sz for those that are already genetically vulnerable
       • Brown et al (1966): families with high expressed emotion levels had 58% of Sz patients returning to hospitals but only 10% for low level EE
     • Overall AO3: Tienari et al (2004)

4. Biological treatments (drug therapy)

   • Typical anti-psychotics
     • Focus on reducing positive symptoms and centered on altering dopamine levels only e.g. Pimozide
   • Atypical anti-psychotics
     • Aimed to treat both positive and negative symptoms + they also block serotonin receptors and don't permanently block dopamine e.g. Clozapine
   • Tarrier et al (2004): 315 people with Sz randomly allocated to: medication/CBT, medication/counselling and medication only (control group) - people who took both medication and a form of therapy had lower symptoms than medication alone

5. Psychological treatments/management

   • Treatments
     • CBT (Personal Therapy)
       • Cognitive techniques include: distractions from intrusive thoughts, challenging their meaning and using relaxation strategies
       • Patients also taught to notice small signs of relapse
       • Tarrier et al (2004)
       • For Sz, it is based on explaining psychological symptoms for causes e.g. helping patient understand their beliefs are false
     • Family Therapy
       • Aims to improve the quality of communication and interaction between family members and reducing stress within the family
         • Pharoah et al (2010): identified a range of strategies that would help, including: forming therapeutic alliance with all family members, helping maintain balance, reducing stress/anger and improving family beliefs about Sz
           • Pilling et al (2002): meta-analysis of psychological treatments and FT had smallest rate of relapse
   • Management
     • Token economies
       • Aimed at challenging negative symptoms and based on operant conditioning
         • Ayllon and Azrin (1968): female Sz patients hospitalised for 16 years on average -> daily number of chores completed rose from 5 to 42
           • However, ethical implications: can be humiliating for patients as rewards are only given if patient complies with desires of those in charge
           • Also, once patient leaves hospital, reinforcers no longer exist -> leads to high readmission rates

6. Interactionist approach

   • Diathesis-stress model
     • Individuals have genetic potentials (diathesis) for Sz that combine with environmental stressors (stress) in their lives to form their vulnerability for the disorder
     • How it has changed
       • Older views: (Meehl 1962) diathesis caused by 'schizogene' and led to schizotypic personality. Without schizogene, no amount of stress would lead to Sz
       • Modern understanding: Sz is polygenic and stress can be anything that risks triggering Sz (even cannabis use)
         • Murray (1996): children whose mothers had flu during second trimester of pregnancy had 88% increased chance of developing Sz
     • Tienari et al (2004)
     • Tarrier et al (2004)
   • The idea that schizophrenia results from a combination of psychological, biological and social factors.