Aetiologies of Schizophrenia

Nota:

• If we believe that schizophrenia is genetic then we'd expect relatives to also have the disease

1. Varma: FDRs of 1000 Sc's and 1000 controls. 16% of schizophrenics FDRs' had Sc
   1. However, we would expect it to be 100% if it is caused by genes
2. Twin Studies
   1. Rosenthal: Genain twins. Quadruplets all had Sc which suggests it's genetic
      1. However, could be environmental as it developed at different ages
      2. Their parents also might've been Sc which develops the study
         1. Again, environment.
      3. Lacks generalisability
   2. Gottesman: Concordance rates in MZ were 48% and 17% in DZ
      1. However, would expect it to be 100%
   3. Joseph: Found a concordance rate of 40.4% in MZ and 7.4% for DZ
      1. However, would expect it to be 100%
3. Family Studies
   1. Gottesman: 13% CR in children and 9% CR in siblings
   2. Gottesman and Bertelsen: 17% CR if a parent had a Sc twin
      1. Would expect it higher, must be something else in play
4. Adoption Studies

   Nota:

   • If a person has more in common with their gene family, it's genetic and vice versa
   1. If a person has more in common with their gene family, it's genetic and vice versa
   2. Tienari: 164 adoptees. 11 with Sc parents went for treatment, whereas only 4 in the control group
      1. Again would expect 100%

1. Nuerons that transmit dopamine fire too easily or too often, leading to Sc
2. Sc's are thought to have too much D2 receptors
3. Chlorpromazine is effective in Sc treatment; it blocks dopamine receptors
4. L-Dopa can cause symptoms of Sc; increases dopamine
5. Amphetamine makes the brain think there is too much dopamine; produces symptoms of Sc

1. Many researchers now believe there must be other factors rather than heredity

1. When researchers don't know if they are studying a MZ or DZ twins report lower CRs for MZ twins
   1. However it is still significantly higher
2. Joseph: MZ twins are more likely to look like eachother and act similarly than DZ twins which could be why CRs are so much higher for MZ twins. Only based on environment
   1. Could be the same for family and adoption studies

1. Gottesman: twins reared together or reared apart have very similar CRs
   1. Adopted children usually have contact with their birth family

1. Drugs that increase dopamine cause symptoms of Sc
2. Neurons struggle to compensate for dopamine loss which could increase Sc symptoms

1. Freud: Said Sc due to conflict within the tripartite personality
2. Ego regresses back to infancy and ries to gain control
3. Sc is driven by sexual impulses which is why it develops in adolescence

1. Birley: Sc reported twice as many stressful events compared to a healthy control
2. Day: Several countries. Found that Scs had more stressful life events prior to diagnosis

1. Bateson: If a child is given mixed messages from parents it could develop into Sc
2. RD Laing: Sc is a reasonable response to an insane world
3. Prevents a development of reality

1. Sc doesn't always develop in adolescence
2. No scienftific evidence to prove/disprove Freud's theories
3. Sterling and Hellewell: found Sc behaviour is not similar to infantile behviour

1. Lack of evidence
2. Lidz: argues Sc occurs as a result of destructive parental relationships
3. Berger: found a higher recall of double bind statements from Scs
   1. Recall may be affected by their Sc
4. Mischler and Waxler: Mothers would talk more normal to their normal children which suggest that mothers create an environment which reinforces their Sc
   1. Sc may only respond in a specific way
5. Kavanagh: Sc in families with low expressed emotions were 4x more likely to relapse
   1. Cause and effect, which causes which?

1. Day: we do not know if the stressful events causes Sc or stressful events causes the genetical onset of Sc
2. Van Os: Reported no link between LE and Sc
3. Social Causation Hypothesis states that lower class are experienced to more stressful LEs
   1. Changing classes could also be stressful