neural correlates

• P: much of the evidence supporting the dopamine hypothesis comes from the success of drug treatments that attempt to change levels of dopamine activity in the brain.

  E: Leucht carried out a meta analysis of 212 studies. they concluded that all the antipsychotic drugs tested in these studies were more effective than placebo in the treatment of positive and negative symptoms, achieved by reducing the effects of dopamine

  L: these findings also challenge the classification of antipsychotics into typical and atypical groupings because differences in their effectiveness were only small
• P: Noll claims there is strong evidence against both the original dopamine hypothesis and the revised dopamine hypothesis

  E: he argues that antipsychotic drugs do not alleviate hallucinations and delusions in about on third of people experiencing these symptoms. noll points out that hallucinations and delusions are present despite levels of dopamine being normal

  L: this suggests that, rather than dopamine being the sole cause of positive symptoms, neurotransmitter systems, acting independently of the dopaminergic system, may also produce the positive symptoms associated with schizophrenia