Neurotransmitters as an Explanation of Schizophrenia

• What are neurotransmitters?

  Electrochemical messengers transmitting nerve impulses
• What is the role of excitatory neurotransmitters?

  They create a positive charge, increasing neuron firing
• What do inhibitory neurotransmitters do?

  They create a negative charge, decreasing neuron firing
• What does the original dopamine hypothesis suggest?

  Dopamine hyperactivity causes positive symptoms of schizophrenia
• What do post-mortem examinations reveal about schizophrenia brains?

  Higher density of dopamine receptors in cerebral cortex
• What does hypersensitivity of D2 receptors indicate?

  Increased response to dopamine presence in patients
• What did Lieberman find regarding drug use and schizophrenia symptoms?

  75% of patients show increased symptoms with dopamine mimics
• What limitation exists in the dopamine hypothesis regarding drug use?

  Only a small proportion of drug users develop psychotic symptoms
• What does the revised dopamine hypothesis state about positive and negative symptoms?

  Positive symptoms are excess dopamine; negative symptoms are deficits
• How does reduced dopaminergic activity affect receptor sites?

  Excess receptor sites may develop in another area
• What is the role of antipsychotics in treating schizophrenia?

  They block dopamine receptors and reduce stimulation
• What did Alpert and Friedhoff find regarding dopamine antagonists?

  Some patients showed no improvement with dopamine antagonists
• What is the mesocortical pathway's role?

  It affects motivation, emotion, and executive functioning
• What symptoms arise from a dopamine deficit in the mesocortical pathway?

  Negative and cognitive symptoms like low mood
• What is the role of the mesolimbic pathway?

  It is involved in decision making and reward
• What symptoms are caused by excess dopamine in the mesolimbic pathway?

  Positive symptoms like auditory hallucinations
• How does the neurotransmitter theory explain negative symptoms of schizophrenia?

  Reduction of dopamine leads to social withdrawal
• What is glutamate's role in schizophrenia?

  Regulates dopamine and is linked to symptoms
• What happens when there is a failure in the cerebral cortex regarding glutamate?

  It leads to negative symptoms of schizophrenia
• How does serotonin affect dopamine levels?

  It balances dopamine levels in the mesolimbic pathway
• What did Lindström et al. find regarding L-DOPA and schizophrenia patients?

  L-DOPA uptake was quicker in schizophrenia patients
• What is a limitation of research into the dopamine hypothesis?

  It is correlational and lacks cause-effect evidence
• What is the stress diathesis model in relation to schizophrenia?

  • Combination of environmental and biological factors
  • Environmental factors trigger biological predisposition
  • Provides a detailed explanation of schizophrenia causes
• How can the neurotransmitter explanation be applied in treatment?

  • Antipsychotic drugs block dopamine receptors
  • Reduces stimulation and alleviates symptoms
  • Improves quality of life and stability for patients