PSYC module 3

• Schizophrenia


  The most common of psychological disorders
• Worldwide, 0.5-1% prevalence of schizophrenia
• Schizophrenia


  • Often referred to as the prototypical psychotic disorder, because you tend to see disturbances in each of the 5 symptom domains
  • Arguable one of the highest impact disorders in terms of impact on individuals, peers and cost
• Onset of schizophrenia


  More common between 15-35yo, uncommon for people to develop it before 10 or after 40
• Late onset schizophrenia


  Develops after 40yo
• Average age of onset


  Males develop schizophrenia around 21yo, females around 27yo
• Risk factors for suicide in people with schizophrenia


  • Being male
  • Being younger
  • Having a higher level of education
  • Family history of suicide
  • Comorbid substance use
  • Depressive symptoms
• People with schizophrenia, on average, die much earlier than expected, with up to 40% of this premature mortality able to be attributed to suicide and unnatural deaths
• Socioeconomic status and schizophrenia


  Lower socioeconomic status is a social factor associated with the incidence of schizophrenia
• Schizophrenia is one of the most expensive mental illnesses in terms of how much money it costs the community
• Annual societal cost of schizophrenia in England


  • 11.8 billion pounds (approx. $15 bill USD, $20 bill AUD)
• Direct costs of schizophrenia


  • Health sector costs (e.g. hospital visits, GP, medication)
  • Accommodation (e.g. crisis care)
  • Services (e.g. employment support)
• Indirect costs of schizophrenia


  • Productivity losses (difficult to remain employed)
  • Lost revenue through income tax forgone due to lack of productivity
  • Cost of transfer payments (income support payments and pensions)
  • Costs associated with absenteeism
  • Disability Adjusted Life Years (DALYs)
• Diagnostic criteria for schizophrenia (DSM-5)


  • Delusions
  • Hallucinations
  • Disorganised speech
  • Disorganised or catatonic behaviour
  • Negative symptoms
• Positive symptoms


  Behaviours that happen too much (e.g. delusions, disorganised speech, hallucinations)
• Negative symptoms


  Behaviours that happen in deficit (e.g. flat affect, alogia, avolition)
• Violence is not a symptom of schizophrenia
• Phases of schizophrenia


  • Prodromal phase
  • Active phase
  • Residual phase
• Prodromal phase


  Decline in functioning, negative symptoms start to appear, lead-in to active phase
• Active phase


  Positive symptoms begin to appear
• Residual phase


  Person presents as significantly more well compared to active phase, positive symptoms have typically remitted, some negative symptoms remain
• Biological factors in the aetiology of schizophrenia


  • Genetic predisposition
  • Structural brain abnormalities
  • Biochemical abnormalities (especially involving the neurotransmitter dopamine)
• Social factors in the aetiology of schizophrenia


  • Low socioeconomic status
  • Social isolation
  • Poor nutrition
  • Lack of access to medical services
  • Stress
  • Social dislocation (higher rates among migrants)
• Psychological factors in the aetiology of schizophrenia


  • Expressed emotion (level of criticism, hostility, and emotional over-involvement within a family)
  • Family burden
• Diathesis-stress model of schizophrenia


  Proposes that there is an underlying vulnerability (likely genetic) that may only convert into illness in the context of environmental stressors
• Diatheses for schizophrenia


  • Genetic factors
  • Physical trauma prenatally or during birth
  • Structural abnormalities of the brain
  • Abnormalities in the neurotransmitter systems
• Stressors for schizophrenia


  • Chronic psychological and social stressors (e.g. poverty)
  • Family environment with high expressed emotion
  • Drug use (especially marijuana)
• Treatments for schizophrenia


  • Medication (anti-psychotics)
  • Psychoeducation
  • Behavioural strategies
  • Cognitive behavioural therapy
  • Family support
• 25% of people with schizophrenia fail to improve on anti-psychotic medication
• Anti-psychotic medications are associated with negative side effects like weight gain and tardive dyskinesia
• Types of psychological tests


  • Aptitude (measure future potential)
  • Achievement (measure current ability)
  • Intelligence (measure cognitive capability)
  • Personality (measure character and individual attributes)
• Characteristics of a good psychological test


  • Standardised
  • Reliable
  • Valid
  • Unbiased
• Many publicly available tests are not standardised, e.g. Myers-Briggs (MBTI)
• Test standardisation


  Establishing the average level of performance, variance around the mean, and standard deviation for a relevant population
• Many tests are still standardised on limited sets of the population, which can introduce cultural biases
• Normal distribution


  A lot of scores clump close to the mean, with fewer scores further from the mean, following a bell curve distribution
• Properties of the normal distribution


  • 68% of scores within one standard deviation
  • 95% of scores within two standard deviations
  • 99% of scores within three standard deviations
• Types of reliability


  • Alternate forms reliability
  • Split-half reliability
  • Test-retest reliability
• Validity


  The accuracy of a test in measuring what it is meant to measure
• Types of validity


  • Predictive validity
  • Criterion validity
  • Construct validity