schizophrenia & affective disorders Flashcards
how is schizophrenia described by Bleuler (1911)
- described disorder as a break in reality
identify some positive symptoms of schizophrenia
positive symptoms = symptoms you have
- hallucinations (mistake in perception)
- delusions (mistake in belief)
- persecution delusion (believe they are going to be harmed)
- delusions of grandeur (believes they are god)
- delusions of control (believes someone is controlling their thoughts/mind)
identify some negative symptoms of schizophrenia
negative symptoms = something you lack
- poverty of speech (don’t speak)
- lack of initiative
- anhedonia (lack of enjoying things)
- social withdrawal
identify cognitive symptoms of schizophrenia
- difficulty in sustaining attention
- low psychomotor speed (mental activity)
- deficits in learning and memory
- poor abstract thinking
- poor problem solving
is schizophrenia inherited?
- MZ twins show 48% concordance rate
- if parents had schizophrenia = 46% chance
describe the pharmacology of schizophrenia
- dopamine antagonist (chlorpromazine) diminishes positive symptoms
- evidence comes from administration of dopamine agonist inducing positive symptoms
why do dopamine agonists induce positive symptoms?
two explanations
1/ nucleus accumbens
2/ the dopamine that goes to amygdala
how does the nucleus accumbens explain schizophrenia?
- dopamine neurones come from ventral tegmental area
- projects neurones to nucleus accumbuns
- dopamine neurones in nucleus accumbuns strongly reinforces behaviour
how does the dopamine that goes to amygdala explain schizophrenia?
- dopamine neurones come from ventral tegmental area (midbrain)
- paranoid delusions caused by activity in amygdala
- amygdala = responsible for fear responses, learning emotional responses)
identify the three hypotheses of psychosis
1/ dopamine theory (only accounts for positive symptoms)
2/ NMDA theory
3/ serotonin theory
explain the dopamine theory of psychosis
- suggests psychosis = due to hyperactive dopamine in the mesolimbic pathway
- mesolimbic pathway = transports dopamine from the ventral tegmental area to nucleus accumbens and amygdala
explain the NMDA theory of psychosis
- suggests psychosis = due to NDMA receptor hypofunction (abnormally low function)
explain the serotonin theory of psychosis
- 5-HTT receptor hyperfunction in the cortex
identify brain abnormalities in schizophrenia
- ventricular area = larger in people with schizophrenia
what is thought to cause schizophrenia?
- viral infection around the second trimester
- as babies born in Feb-May found to have schizophrenia
outline what association Schiffman et al. (2002) looked into between schizophrenia and minor physical variations
- found minor physical variations had a relationship with schizophrenia
- if schizophrenia has biological basis, this should translate to other things
e.g.:
- larger head
- wide set eyes
- fold in corner of eye
- asymmetrical ears
- Schiffman suggests prenatal disturbances in 1st or 2nd trimester
- when this combined with second hit (i.e.: birth complications) = increase chance of schizophrenia
what did Davis et al. (1995) find in twins pre-natal environment?
- found twins that share amniotic sac/placenta (monochorionic concordance) = 60% concordance rate
- twins that don’t share placenta (dichorionic concordance) = 10.7%
identify 4 types of affective disorders
- affective disorders = mood disorders
1/ depression
2/ mania
3/ bipolar disorder
4/ unipolar disorder
outline properties of depression
- low energy levels
- anhedonia
- loss of appetite
- sleeping problems
outline properties of mania
- euphoria
- delusional
- poor attention span
- lack of sleep
outline properties of bipolar disorder
- alternating periods of mania and depression
- 1% of population effected at some point in their life
outline properties of unipolar disorder
- depression without mania
what does Rosenthal (1971) say about how more likely you are to suffer from affective disorders if close relative does?
- 10 times more likely to suffer
what is the MZ concordance rate for affective disorders?
69%
what is the DZ concordance rate for affective disorders?
13%
outline pharmacological treatment in affective disorders (depression)
- MOA (monoamine oxidase) = enzyme that destroys monoamines in post synaptic nerve
- examples of monoamine = serotonin, dopamine
what does the drug iproniazid do?
- inhibits MOA
- increases serotonin, dopamine
what do tricyclic antidepressants do?
- agonists of serotonin and Norepinepherine
- inhibits reuptake of neurotransmitter
what does SSRI’s do?
- agonists of serotonin
- inhibits reuptake of 5-HT
what is the monoamine hypothesis?
- suggests that the underlying physiological cause of depression = depletion in levels of serotonin, norepinephrine, and/or dopamine
- in the central nervous system.
outline pharmacological treatment in affective disorders in mania
- lithium carbonate = used to treat mania
- thought to stabilise serotonin release
how does REM sleep impact depression?
- preventing REM sleep acts as antidepressant
- effects of antidepressants = suppressed REM sleep
- this is because REM sleep regulates irregular sleep pattern that is seen in depressed people
