Biological explanations

    Subdecks (1)

    Cards (8)

    • Classic genetic studies

      • Twin studies - Joseph - concordance rate of 40.4% in MZ, 7.4% in DZ
      • Adoption studies - Tienari - bio mothers with SZ - 6.7% in children, 2% without bio mother
    • Candidate gene studies

      • Early research looked for a single, SZ-causing gene
      • SZ is polygenic and aetiologically heterogeneous
      • Ripke et al. - compiled genome-wide studies, found 108 genes associated with SZ risk
      • Benzel et al. - COMT, RDR4, AKT genes cause excess dopamine, leading to positive symptoms
      • Miyakawa et al. - DNA from families with SZ, those with more likely to have a defective PPP3CC gene
    • The Dopamine Hypothesis
      • V1 - Schizophrenia is caused by excess dopamine activity in the brain, particularly the mesolimbic pathway. This was based on the effects of dopamine-blocking antipsychotics and dopamine-releasing drugs
      • V2 - Updated hypothesis added low levels of DA in the prefrontal cortex, which may explain negative symptoms
      • Davis et al. - frontal hyperdopaminergia in rats, frontal lobe lesions and negative symptom correlation
    • Neural correlates
      Patterns of activity in the brain that occur in conjunction with an experience, and may be the cause of the experience