Chapter 16 - Schizophrenia Flashcards
What was an ancient treatment for psychosis? (Neolithic, > 7000 years ago)
Trephination
A hole is drilled into the skull to release spirits and treat headaches
Before the 1900’s, what did people think psychosis was the result of?
Stress and strain of personal/ social interactions
In 1911, what did Hideyo Noguchi do and what did he find?
Examined brains of psychotics
Found that the brains were damaged by syphillis
True or false? Schizophrenia will persist for life only.
False. Can cycle in and out of remission.
What are the early and later definitions of schizophrenia? (Know conventional symptoms)
Early: Paranoia, delusions, hallucinations, abnormal emotions, thought disturbances
Later: Dissociated thinking (lack of logic)
What are five “types” of Schizophrenia?
- Disorganized
- Catatonic
- Paranoid
- Undifferentiated
- Residual
Is Schizophrenia a genetic disorder?
Shows strong genetic predisposition but identical twins do not have 100% concordance. (twin adoption study) (may be due to developmental/environmental difference)
What signs does the schizophrenic twin usually exhibit?
Lower birth weight
More tearful, sensitive, vulnerable
Early neurological signs (eye movement)
What happens with the ventricles in patients with Schizophrenia? What does this suggest?
Enlarged.
Cortical atrophy and neural degeneration. (Consequence, not root cause!)
Early-onset schizophrenia in adolescence is characterized by a (loss/gain) in _____ matter.
Loss, gray
With respect to the limbic system, what is observed with patients with Schizophrenia?
Smaller hippocampus and amygdala
Schizophrenia patients have a (smaller/larger) cerebellar vermis?
Smaller
During frontal cortex development, what may also be observed in patients? What is this consistent with?
Abnormal neuronal migration
Consistent with impaired performance on frontal lobe dependent tasks.
In patients, frontal lobe neuronal complexity is (less/more)?
Less
How is the hippocampus organized in patients?
Cells are disorganized, results in abnormal inputs and outputs
In the hippocampus, what is correlated with severity of disease?
Degree of disorganization
Using PET and fMRI, what has been observed in the frontal lobes of patients?
Lower metabolic activity, even at rest
What is the effect of antipsychotics?
Increase frontal lobe activity
What are the two main theories of Schizophrenia?
- Dopamine hypothesis
2. Glutamate hypothesis
Why is it difficult to study Schizophrenia and why?
Hard to separate cause from effect because Schizophrenia = heterogenous disease (could have different causes for different symptoms)
[Dopamine hypothesis] With amphetamine psychosis, what is the dose required by amphetamine addicts and why?
3000 mg/day (5 mg for normal person keeps them awake!)
Due to drug tolerance
[Dopamine hypothesis] With amphetamine psychosis, what is the dose required by amphetamine addicts and why?
3000 mg/day (5 mg for normal person keeps them awake!)
Due to drug tolerance
[Dopamine hypothesis] What are the effects of using too much amphetamine?
Paranoia, delusions of persecution, auditory hallucinations, strange motor behaviour
Amphetamines make schizophrenic symptoms (better/worse)?
Worse
Amphetamines make schizophrenic symptoms (better/worse)?
Worse
What do typical antipsychotics do and with which hypothesis does this support?
Block D2 receptors
Dopamine hypothesis
In Parkinson’s patients, what drug can produce schizophrenic symptoms?
L-DOPA
What does the ‘Dopamine Hypothesis’ suggest?
Schizophrenia may result from excessive synaptic dopamine or excessive postsynaptic sensitivity to dopamine
What are the four main problems with the DA hypothesis?
- DA antagonists don’t help all patients
- Atypical antipsychotic drugs (works better!)
- Dopamine metabolites in CSF, blood, urine (normal levels)
- Therapeutic lag (DA receptors blocked quickly but symptoms reduced later)
Atypical antipsychotic drugs have low activity of what and is it (more / less / just as) effective for positive symptoms? Negative symptoms?
Low D2 activity
Just as effective for positive symptoms
More effective for negative symptoms
(Note: can increase dopamine release, and L-DOPA combined with atypical works better!)
What is the ‘Glutamate Hypothesis’?
Schizophrenia may be caused by decreased activity at NMDA receptor
What acts as an NMDA antagonist?
Phencyclidine (PCP)
What acts as an NMDA antagonist?
Phencyclidine (PCP)
What can PCP induce?
Positive and negative symptoms similar to schizophrenia (psychomimetic)
Prolonged administration (2 weeks) resulted in what in monkeys?
Decreased performance on prefrontal cortex dependent tasks
What is the ‘Integrative Model’ for treatment?
Identify those with biological predispositions (brain abnormalities) and provide them with lower stress environments
