Lecture 24 - Psychosis Flashcards
(58 cards)
describe a range of mental disorders that involve symptoms of psychosis
psychotic disorders
refers to mental disorders in which there is a loss of contact with reality, affecting a person’s ability to think, feel, and act
psychosis
a severe psychotic disorder that is diagnosed if a person has two or more symptoms for six months
schizophernia
what are the positive symptoms of schizophrenia?
mental phenomena that are absent in healthy individuals (ie: hallucinations and delusions)
what are the negative symptoms of schizophrenia?
loss or impairment of normal psychological function (ie: loss of motivation and social withdrawal)
what are the cognitive symptoms of schizophrenia?
poor concentration, disorganized thinking, poor memory, etc
the risk of developing schizophrenia is highly influenced by:
genes
when does schizophrenia most often manifest?
early adulthood
one common theory is that schizophrenia is a:
biochemical brain disease
true or false: generally, neurons predominantely release one neurotransmitter
true
what is the dopamine hypothesis?
the symptoms of schizophrenia are due to the hyperactivity of the dopamine system
what are the two major pieces of evidence for the dopamine hypothesis?
- drugs that increase synaptic dopamine can cause delusions and hallucinations at high doses
- drugs that block dopamine receptors are effective antipsychotics
the largest population of dopamine neurons are located in the:
midbrain (ventral tegmental area and substantia nigra)
dopamine neurons located in the ventral tegmental area project to the striatum and the prefrontal cortex
mesocortical/mesolimbic system
the mesocortical/mesolimbic system normally mediates:
memory, learning, and thought organization
hyperactivity of the mesocortical/mesolimbic system contributes to:
psychotic symptoms
blocking dopamine transmission is effective at treating:
the positive symptoms of schizophrenia
what type of receptors are dopamine receptors?
GPCRs
what are the two classes of dopamine receptors?
D1 receptors and D2 receptors
class of dopamine receptors which stimulate adeylate cyclase via Gs proteins and subsequently activate cAMP dependent protein kinases
D1 receptors
class of dopamine receptors coupled to Gi proteins and inhibit the activity of adenylate cyclase
D2 receptors
which class of dopamine receptors is directly related to clinical anti-psychotic potency?
D2 receptors (D1 are unlikely to contribute to therapeutic actions of anti-psychotics)
dopamine neurons in the substantia nigra that project to the striatum?
nigrostriatal system
the nigrostriatal system is normally involved in:
movement initiation