Biological Explanation: Dopamine Hypothesis Flashcards
What has the problem with dopamine in people with schizophrenia hypothesised to be?
excess dopamine, excess of dopamine receptors, super-sentivity of receptors
What has the problem with dopamine in people with schizophrenia hypothesised to be?
excess dopamine, excess of dopamine receptors, super-sentivity of receptors
Why is there a problem of causality with the dopamine hypothesis?
evidence is correlational, could be that dopamine dysfunction causes schizophrenia or the other way around, even if this is the case: what causes the dopamine dysfunction
Why is there a problem of causality with the dopamine hypothesis?
evidence is correlational, could be that dopamine dysfunction causes schizophrenia or the other way around, even if this is the case: what causes the dopamine dysfunction
What 2 types of evidence suggest a causal relationship between dopamine and schizophrenia?
L-dopa: drug increases dopamine levels, leads to schizophrenic symptoms in Parkinson’s patients. Amphetamines: increases dopamine activity, increase/worsen schizophrenic symtoms
How does the dopamine hypothesis seem to not apply to everyone with schizophrenia?
drug treatments don’t help all patients, not all amphetamine/L-dopa users get schizophrenic symptoms, dopamine involvement not involved in negative symptoms
What is the amendment to the dopamine hypothesis? Who proposed it?
The final common pathway. Howes and Kapur, dopamine is the common mechanism that produces psychotic symptoms, there is a pre synaptic dopamine dysfunction
What causes pre-synaptic dopamine dysfunction?
obstetric (pregnancy) complications, genes, stressors, drugs (amphetamines), family factors (Expressed Emotion) - results from multiple factors
What causes pre-synaptic dopamine dysfunction?
pre natal factors, genes, stressors, drugs (amphetamines) - results from multiple factors
What are the psychological affects of dopamine dysregulation?
alters the appraisal of stimuli through the process of ABERRANT SALIENCE, what is relevant/irrelevant information?
How is the dopamine hypothesis different from the diathesis stress model?
Diathesis stress says that all schizophrenia has a genetic basis whereas the hypothesis says that psychosis could develop just from environmental factors and no genetics
What is wrong with the current schizophrenia drug treatments according to the dopamine hypothesis?
Current antipsychotics act postsynaptically when they should be acting on the actual dysregulation which is causing the increased synthesis/release of dopamine
How do genes, environment and interaction of these all contribute to dopamine dysregulation?
Genes that most raise the risk of schizophrenia are the ones that are associated with dopaminergic pathways, environment affects when associated with social isolation and stress, interaction starts early e.g. experiences that affect dopamine prime the brain for later responses
What is the evidence for the locus of dopamine dysregulation being presynaptic?
Howes 2012: meta analysis of brain scans found high rates of presynaptic dopaminergic function in schizophrenia, other dopamine dysfunction less pronounced
What is the evidence for the locus of dopamine dysregulation being presynaptic?
Howes 2012: meta analysis of brain scans found high rates of presynaptic dopaminergic function in schizophrenia, other dopamine dysfunction less pronounced
