Prognosis:

• ~ 45% schizophrenia cases recover after 1/more episodes
• ~ 20% show constant symptoms + increased disability
• ~ 35% display varied degrees of progress/deterioration
• Extremely high suicide rate:
  Nannerz et al (2001) - 30% schizophrenic patients attempted suicide at least once during lifetime
  Radomsky et al (1999) - 10% of schizophrenic people die by suicide

• Risk of developing schizophrenia <1% in general population
• Risk of developing schizophrenia 2-9% if first degree relatives
• Risk of developing schizophrenia 1.5-3% if second degree relatives
• Rudin (1916) - Schizophrenia tends to cluster in families

Twin Studies:

• MZ twins = ~ 50% concordance rate
• DZ twins = 4% concordance rate
• Suggests genetic link, but also other factors involved (e.g. environment)

• Similar representation + prevalence worldwide = widespread environmental factors
• Typically develops in early adulthood = environmental role during development

Retrospective studies limitations:

• Selective + incomplete recall
• Search after meaning - Look for particular instances to explain condition
• Expensive to conduct widescale study
  Follow-back studies limitations:
• Objective evidence often sparse/missing/lost/not detailed

• Can interfere with foetal brain development
• High risk of child developing schizophrenia in women:
• Whose partner died during pregnancy (Huttunen, 1989)
• Affected by battle/war during pregnancy (Van Os + Selten, 1998)

Perinatal Complications:

• Babies experienced birth complications = 2x as likely to develop schizophrenia (Cannon, 1997; Jones, 1998)
• Birth complications lead to hypoxia (lack of oxygen in organs + tissues)

Eve Johnstone et al (1999) High risk study:

• Followed up 155 ppts aged 16-24 at risk of getting schizophrenia
• Compared to 36 controls
• Estimated risk of developing schizophrenia = 10-15%

Miller et al (2001):

• Compared cannabis use in ppts who developed schizophrenic symptoms + ppts who didn't
• Cannabis is a risk factor for developing psychotic symptoms in vulnerable young people
  Di Fortio et al (2015):
• Compared 410 patients with 1st psychotic episode with 370 controls between 2005-2010
• 2.9x higher risk of developing psychotic disorder for cannabis users
• 5.4x higher risk of developing psychotic disorder for skunk users
• ~ 1/4 of 1st psychotic episodes due to skunk use

Urban upbringing

• Being socially isolated increases risk of developing schizophrenia
  
  

Kirkbride et al (2014):

• Incidence of non-affective psychosis affected by inequality, absolute deprivation, population density
• For Black Caribbeans + Black Africans, risk was associated with ethnic separation, ethnic density

Dysfunctional families
Gregory Bateson

• 'Double Bind' (say something but expect the opposite)
  E.g. Complain about lack of affection but push away child when trying to hug

Dysfunctional families: Hirsch + Leff (1974)

• Compared parents of schizophrenic patients with parents of people with other disorders
• More communication deviance in parents of schizophrenic patient
• Small no. of parents spoke much
• When communication was controlled, no difference between groups

Leff + Vaughan (1976)

• Recruited patients on admission + followed up on discharge
• Observed families in naturalistic settings
• Recorded + transcribed communication
• Rated each for expressed emotion
• Found: Patients in high expressed emotion families showed high relapse rate 1 year after discharge
• Strength: Replicated many times
• Limitation: Direction of causality unknown

Miller et al (2001)

• Compared life events of schizophrenic ppts + non-schizophrenic ppts
• High risk ppts with more life events = greater risk of developing schizophrenic symptoms
• Minor life events not significantly associated with schizophrenic symptoms
• Limitation: Causation problem - life events = symptoms, or vice versa?

Revised dopamine hypothesis:

• Overactivity of dopamine Mesolimbic pathway = Positive symptoms
• Both typical + atypical anti-psychotics:
• Block dopamine
• Reduce mesolimbic activity

• Reduce positive symptoms

  
  

• Underactivity of dopamine mesocortical pathway = Negative symptoms

• Atypical anti-psychotics:
• Block serotonin
• Reduce inhibition of mesocortical pathway
• Increase mesocortical activity
• Reduce negative symptoms