Psychiatric Disorders - Schizophrenia Flashcards
What is the biggest controversial sex difference in psychiatric disorders
the main one is mood disorders more common in woman but only because it is more accepted. believe their is a large cause from the social cultures and not actually a biological component.
What are the statistics about have mental illness and having a substance abuse problem
twice as likely to have a substance abuse when having a mental illness
Kraeplin’s discovery of common symptoms in schizophrenia (5)
disturbances in thoughts
delusions
auditory hallucinations
odd array of emotional changes
thought to begin during adolescence and moves to chronic state of cognitive impairments
What did Eugen Bleuler do in relation to schizophrenia
he introduced the term schizophrenia
identified dissociative thinking as a key symptom of schizophrenia
Define positive symptom vs. negative symptom
positive = something emerging that is normally not there
negative = something that should not be there (ex. an emotional reaction that is not usually there)
What results for found in relation to genetic contributions for schizophrenia
monozygotic twins have a risk of schizophrenia of 48% that suggests there is not a 100% penetration of genes, meaning that there are other factors and something else needs to happen in order for schizophrenia to be developed.
What structural changes in the brain were found in schizophrenic patients? (3)
- ventricular enlargement
- limbic system alteration (specifically in the pyramidal cells)
- (hypothesis) for prefrontal cortex changes
What was the biggest structural change found in the brain for people with schizophrenia and why? (1)
ventricular enlargements
(data found that ventricular enlargement was found in twins that are schizophrenic compared to unaffected)
Also found that enlargements were more pronounced in males
Because the tissue or brain is damaged and the tissue disintegrates causes more room for the ventricle to increase in size
What other structural changes occurred in the brain of schizophrenic patients
limbic system abnormalities
the pyramidal cells in the hippocampus were reported to be disorientated. mainly in CA1 and CA3. Wasn’t necessarily fewer cells, but their organization was altered. the axon-dendrite organization was not all in a line, they were pointed in all directions which altered the sending information (not displayed in all schizophrenic patients however)
What structural changes in the brain were found in schizophrenic patients? (3)
- ventricular enlargement
- limbic system alteration (specifically in the pyramidal cells)
- (hypothesis) for prefrontal cortex changes
Hypofrontality Hypothesis
that there are significant impacts on the prefrontal cortex, which is true. The prefrontal cortex is quieter, less reactive when challenged.
What was a regional and cellular abnormality found in schizophrenic patients
altered gene expression: specifically inhibitory neurons in the prefrontal cortex
Wisconsin Card Sorting Task (WCST)
start by testing on rule (ex. colour), then change rule without telling the subject (ex. change to number matching). Prefrontal damage can do original task, but when change the rule they cannot perform this task, they could even tell you about the rule change but couldn’t actually perform the rule. Schizophrenic cannot do this test.
Dopamine Hypothesis
theory that there is excessive dopamine levels which is the root cause of symptoms of schizophrenia
Dopamine is interesting because it comes from many different cell groups and projections. D2 receptors are specifically important, they cause inhibition when activated. D1 cause excitation when activated. So depending on which is affected to see different results
What area seems to be funky with how they project in terms of dopamine
ventral tegmental area to the nucleus accumbens, cortex, and hippocampus
What is a criticism of the dopamine hypothesis model
dopamine metabolites in blood and urine are not consistent in patients, some patients have effects of some symptoms while other do not.
What are the two alternative models to the dopamine hypothesis model
that instead the prenatal development of hippocampus and/or the amygdala may be a critical event in the overall cause of schizophrenia
some combination of GDE factors would alter the development of the hippocampus and/or amygdala and their the relationships to the rest of the brain
What did the rat models display
led by weinberger
that change in structures lead to different symptoms of schizophrenia, specifically in nucleus accumbens and prefrontal cortex. also hippocampus and amygdala
What was done to the rats
newborn rat pups had small lesions in either amygdala or hippocampus, left and grew up, this led to abnormalities in adulthood.
What abnormalities occurred in rats after the experiment
enlarged ventricles, increased postsynaptic dopamine receptor action, morphological changes in prefrontal cortex, and deficits on tasks specific to prefrontal cortex function
Summary of rats model
alterations in depamine related behaviour and prefrontal function are a secondary consequence of prenatal alterations (organization changes which alters interactions)
What is the connection of genes to schizophrenia
128 gene mutations associated with schizophrenia, changes in D2 receptors and glutamate
