Causes Flashcards
What is evidence of a gene environment interaction for schizophrenia
Children of parents wih schizophrenia have a higher chance of having disorder even if adopted however protective factor of healthy supportive environment
What are genetic causes of schizophrenia
Multiple gene variances combine to produce vulnerability
How can you develop schizophrenia if your parents don’t have it
Study of children of fraternal and identical twins. Same risk for schiZo if parent is mono twin but no schzo but twin does. Fraternal then risk drops if parent not schzo but twin does
What are the endophenotype candidates for schizophrenia
Genes that regulate processes such as
Smooth eye movement or eye-tracking
Cognitive deficits eg emotion identification
What is the dopamine hypothesis
Schizophrenia is attributed to excessive dopamine activity
What is the circumstantial evidence for dopamine role in schizophrenia
Dopamine antagonists block release of dopamine by occupying receptors this is how antipsychotics work (neuroleptics)
Neuroleptics can cause Parkinson type side effects (insuff dopamine)
Dopamine agonists used for Parkinson’s makes psychosis
Amphetamines also activate dopamine and make psychotic symp worse
What evidence contradicts dopamine hypothesis
Significant number of schizophrenics not helped with dopamine antagonists
The action of neuroleptics is quick but relevant symptoms take days or weeks to subside
Drugs only partly helpful in reducing negative symptoms
What are the 3 neurochemical abnormalities w schiOphrenia
Excessive stimulation of D2 receptors
Hypofrontality - deficits in prefrontal section
Glutamate transmission and their receptors NMDA
What brain structures are abnormal in schizophrenia
Enlarged ventricles so adjacent parts may be atrophied
Hypofrontality- less active prefrontal lobes
What other environmental factors
Prenatal and perinatal conditions contribute to development
Viral infection preg complications and delivery problems
Cannabis use but conflicting findings
Psychological influences on development of schizophrenia
Stress
Urban living
Which particular emotional communication is being researched w schiZophrenia
Expressed emotion - includes levels of: Criticism (disapproval) Hostility and animosity Emotional overinvolvement (intrusiveness) All related to relapse
What are the causes of schizophrenia
Genetics predispose to schizophrenia
Increased dopamine activity
decr serotonin activity
Low levels of neurological activity in frontal lobes (hypofrontality)
Brain abnormalities eg enlarged ventricles, atrophy of cortex
What is difference in dopamine receptors in people with schizophrenia
Schizophrenia has more dopamine receptors than normal
How does serotonin affect dopamine levels
Serotonin is an inhibitory neurotransmitter
It keeps dopamine levels in check in normal individ
But in schizophrenia, serotonin levels are low, so don’t keep dopamine levels balanced and dopamine goes up.
