psychology: schizophrenia

• Types of delusions

  • Grandiose
  • Persecutory
  • Control
  • Referential
• Auditory hallucinations


  Critical of the sufferer or give a running commentary of their lives
• Positive symptoms


  Additional experiences beyond those of ordinary existence, including hallucinations and delusions
• Persecutory delusion


  Believing they are being persecuted
• Speech poverty


  Inability to speak properly, characterized by a lack of ability to produce fluent speech; reflects slowing or blocked thoughts
• ICD-10 diagnosis of SZ

  1 first-rank symptom e.g. auditory hallucinations, thought insertion, delusions or 2 or more symptoms from hallucinations, catatonic behavior, negative symptoms
• This subjectivity is a problem for SZ due to the constructed and subjective nature of symptoms and categories
• Inter-rater reliability


  Refers to whether two different therapists can agree on their diagnosis of the same patient
• Differences between ICD-10 and DSM-5 for diagnosing SZ

  ICD-10 recognizes SZ subtypes, DSM-5 doesn't. ICD-10 requires symptoms present for one month not including social and occupational dysfunction, whereas DSM-5 does
• Referential delusion


  Believing words in books, maps, song lyrics have a special message for them to follow
• Davidson et al. say that categories to diagnose mental illness are constructs as clinicians have combined symptoms for diagnostic criteria
• Delusions


  False, irrational beliefs
• Comorbidity refers to more than one disorder existing along with SZ
• Symptoms and categories of SZ are subjective
• Schizophrenia is a mental illness that occurs in late adolescence or early adulthood. In DSM, it is classed as psychosis as the sufferer has no concept of reality. It is an illness due to the breakdown of the patient's personality
• Grandiose delusion


  Believing they are an important historical, political, or royal figure
• Negative symptoms


  Reducing an individual's behavior (decline)
• Control delusion

  Believing they are under the control of an external force that has invaded their body or mind
• DSM-5 diagnosis of SZ

  At least 2 symptoms from delusions, hallucinations, disorganized speech, catatonic behavior, negative symptoms. If they have auditory hallucinations, this is enough for a diagnosis
• Major issue with the classification of SZ is subjective terms like 'persistent behavior change' and 'social dysfunction'. Terms may be viewed differently by therapists leading to different diagnoses
• Hallucinations


  False perceptions which take sensory form e.g. auditory hallucinations. They can also be visual, tactile, or involve taste
• Avolition


  Reduction, difficulty, or inability to start and continue with goal-directed behavior e.g. no longer interested in engaging in social activities and sitting inside doing nothing
• Davidson et al: 'Due to the constructed and subjective nature of SZ, the idea of diagnosis and classification for SZ being incorrect is highly possible'
• Davidson et al: 'Categories to diagnose mental illness are constructs as clinicians have combined symptoms for diagnostic criteria'
• Low inter rater reliability


  Greater chance of disagreement between clinicians
• Fernando: 'Research suggests white middle class, western males are constructing the symptoms which has implications for higher rates of diagnosis in African Caribbean populations'
• Ripke et al (2014): 'Carried out meta-analysis of previous data + identified 108 gene variations associated with increased risk of disorder. More gene variations one has, greater the risk of developing SZ'
• Symptom overlap


  Where SZ symptoms overlap with other conditions
• Slater and Roth (1969): 'Argue that all symptoms of SZ are the least important of SZ symptoms because they aren't exclusive to the disorder/ none of them are exclusive to SZ'
• 13%
• How a COMT gene variation increases dopamine: 'Faulty COMT gene - which has issues with COMT enzyme production so there isn't enough COMT enzyme to breakdown dopamine. Increase in dopamine thought to trigger SZ symptoms'
• Diathesis: 'Diathesis stress model which looks at genetic vulnerability + triggers environment seems to be a more suitable explanation rather than genes alone'
• Changes in the level of dopamine: 'Thought, perception, and emotions'
• Dopamine hypothesis: 'The brain of an SZ person produces more dopamine than the brain of a non-SZ person. It's also thought SZ's have an abnormally high number of D2 receptors'
• Higher if genetic: 'If share 50% of genes with mother expect to be higher than 6.7% if solely genetic. Suggests genes are a factor, not determinant in environment. Maybe due to complex interaction between genes + environment'
• Hyperdopaminergia (in subcortex): 'High levels or activity of dopamine in Subcortex thought to be responsible for SZ symptoms'
• Davidson et al: 'Misdiagnosis and treatment'
• Genetic explanation


  There is a number of genes that contribute to susceptibility of SZ but none exhibit full responsibility for disease (Polygenic)
• Gottesman (1991): 'Concordance rates in MZ twins 48%. 17% in DZ twins, figure higher with MZ twins suggests genetic basis for SZ. Not purely genetic as 48% not 100%, environmental. MZ twins brought up similarly may react to triggers differently e.g. divorce greater 'stressor' for 1 twin than other, CR isn't 100%'
• Comorbidity implications for treatment

  If 2 disorders are identified, only one can be treated