Module 15.2 Flashcards
What are the negative symptoms of schizophrenia?
weak social interactions, emotional expression, speech and working memory
What are the two clusters of positive symptoms of schizophrenia?
psychotic and disorganized
What is the main cognitive problem in schizophrenia?
disordered thoughts
What physiological problem might underlie schizophrenia?
abnormal interactions between the cortex and the thalamus and cerebellum
What is the overall incidence of schizophrenia?
1% of people
Does the incidence of schizophrenia vary by gender or ethnicity?
It does not vary by ethnicity, but it more common in men than women
*What evidence from twins suggests a genetic basis for schizophrenia? What are the concordance rates?
Monozygotic twins have higher concordance than dizygotic
How might one form of the DISC1 gene increase the incidence of schizophrenia?
It controls the rate of generation of new neurons in the hippocampus
What can we conclude about the role of genetics in schizophrenia?
Some cases do have a genetic bases, others do not
What evidence suggest that schizophrenia may result from abnormalities in the early development of the brain?
Several kinds of prenatal or neonatal difficulties are linked to later schizophrenia and people with schizophrenia have minor brain abnormalities that apparently originate early in life
During which season of birth is there a slightly greater likelihood of developing schizophrenia? What factor may account for this effect
winter; complications of delivery or early nutrition or flu virus
What brain abnormalities have been linked with schizophrenia?
smaller left temporal and frontal areas of the cortex and thalamus
ventricles are larger than normal
Why do researchers believe the abnormalities resulted from developmental defects, rather than from gradual brain damage in adulthood?
Many studies have found no significant differences in the brains of older & younger patients
How might one explain the late onset of schizophrenia symptoms, if the damage occurred early in development?
The prefrontal cortex isn’t developed until adulthood
What is the dopamine hypothesis of schizophrenia? What are the main lines of evidence favoring it?
The idea that schizophrenia results from access activity at dopamine synapses in certain brain areas. Large, repeated doses of amphetamine, methanphetamine, and cocaine induce substance-induced psychotic disorder
What are two chemical families of antipsychotic (neuroleptic) drugs that have been in wide use for many years? What is their major effect of receptors?
Phentothizines and butyrophenones. Block D2 receptors
What drugs can induce a state similar to schizophrenia?
PCP
What is a problem with the dopamine hypothesis?
Block dopamine is important, but antipsychotic drugs block dopamine within hours, but symptoms take weeks to improve, so something else is going on
What kinds of evidence suggests an abnormality in glutamate release or receptors?
the drugs that have the effects of decreased glutamate effect the NTs within hours, but take weeks for symptoms to subside
Why may blockade of dopamine receptors have beneficial effects, even if the original problem is deficient glutamate?
increased dopamine has the same effect as low dopamine, so drugs that block dopamine cause an effect of increased glutamate
What is phencyclidine?
PCP; a drug that inhibit ithe NMDA glutamate receptors
What is PCP’s effects of receptors?
inhibits NMDA glutamate receptors
What are PCP’s psychological effects?
At low doses, it produces intoxication and slurred speech. At larger doses, it produces both positive and negative symptoms of PCP.
What other neurotransmitter, besides dopamine, has been hypothesized to be abnormal in schizophrenia?
glutamate
Why would it be unwise to administer glutamate to schizophrenic people?
excess glutamate can cause stroke
How does glycine affect NMDA receptors? What were the clinical findings regarding glycine?
The NMDA glutamate receptor has one site that is activated by glutamate and another that is activated by glycine. Glycine increases the effects of NMDA glutamate receptor. Studies found that glycine decreases the effects of PCP.
What is tardive dyskinesia?
side effect of neuroleptic drugs characterized by tremors and other involuntary movements
What causes tardive dyskinesia?
the drugs used to treat schizophrenia block dopamine neurons in the mesotriatal system, which projects to the basal ganglia
What are five atypical antispychotic drugs?
Clozpine, amisulpride, risperidone, olanzapine, and aripiprazole
How do the five atypical antipsychotic drugs work?
Antagonize serotonin type 5-HT2 receptors and increase the release of glutamate
What is a major advantage of taking atypical antipsychotic drugs?
they treat the negative effects of schizophrenia, the old drugs only treated the positive
