9 - Psychiatric Disorders Flashcards
define schizophrenia
severe mental disorder characterised by emotional dysregulation and cognitive deficits
difference between males and females
males have more severe forms, pronounced abnormalities and more resistant to treatment
male and female onset
15-25 in males
30 in females
what are the 4 courses of conditions
one episode
several with no impairment
impairment after first episode
exacerbated impairment
define alogia
reduced speech
define anhedonia
decreased ability to find pleasure in things one used to
define avolition
hard to initiate and pursue goal-directed behaviour
define affective flattening
lack of emotional and facial expressoin
define cognitive symptoms
difficulties with aspects of cognition which makes it harder to live a normal life and work
what are the wider areas of impact of schizophrenia
more family stress comorbidity abuse reduced employability and income shame
define affective disorders
mood disorders where disordered feelings arise
some key things about the prevalence, incidence, onset, gender divide, etc. about depression are
15% p, 1% in, early adulthood, females get it more than males after 13 years old, can be continuous or episodes
some key things about the prevalence, incidence, onset, gender divide, etc. about bipolar are
1% p, 4% in, late adolescence, 50:50 males:females, manic and depressive episodes
how much longer are depressive episodes in bipolar than manic
three times longer
examples of manic mood and behaviour in bipolar
impulsivity, recklessness, euphoria
examples of psychotic symptoms in bipolar
delusions, hallucinations
examples of cognitive symptoms in bipoalr
distracted a lot, disorganised, inattentive
examples of dysphoric mood and behaviour symptoms in bipolar
depressopn, anxiety, suicide
in terms of genetics, schizophrenia is what and what other aspect causes it
polygenic
environment
define common variant
caused by a large number of genetic changes each of which has a small effect, involving single nucleotide polymorphism
with common variants in sz, what genes are responsible
MHC gene, DA system, Ca2+ channel functioning, glutamatergic system
define rare variant
rare but highly penetrant genetic changes where DNA has been deleted or duplicated
key gene with rare variants in sz
DISC1 - assoc w scaffolding protein for development, neurogenesis, synaptic/mitochondrial functioning
how does dopamine cause schizophrenia
DA synaptic overactivity in mesolimbic pathway causing +ive but underactivity in the mesocortical causing cognit/-ive
how do low levels of glutamate in the cerbrospinal fluid cause sz
genes influencing glutamate transmission changes, reducing NMDA binding which is linked to neurodevelopment e.g. pruning
how do serotonin changes affect sz
linked to -ive symptoms and moderates dopamine
what’s the neurodevelopmental approach towards sz
end of adolescence shows more marked difference in neurobiological processes
where is there less grey matter in those with sz
frontal and temporal cortex, as rapid loss in young adulthood
what do enlarged ventricles filled with water due to brain tissue loss correlate with
correlates with -ive symptoms, drug responsiveness, and cognitive symptoms
during hallucinations in schizphrenics, where is there activity and why
in auditory and visual cortices as brain can’t distinguish between real and imagined sounds and images
define hypofrontality
less activity in the pre-frontal cortex, associated with cognit/ive symptoms
what causes less PFC activity in sz
PCP/ket and indirect NMDA receptor antagonists suppressing the dorsal-lateral PFC
when do MZ twins have a higher concordance rate
shared placenta
where the split of the zygote occurs affects what with MZ twins
how identical the prenatal environment is
6 schizophrenia risk factors
urban area pregnancy fever winter birth childhood cat maternal substance abuse birth comps
why does a winter birth increase risk of sz
can contract a virus, meaning toxins and antibodies affecting brain development and attacking foetal cells may be produced
how do early behavioural changes in individuals predict developing schizphrenia
sz triggered when neurons degenerate via pruning when the NS is developing connections
in the diathesis-stress model, how is the nervous system involved
genetic and env risks trigger expression of genes altering NS function, causing SZ behaviour
in depression, which gene is predisposed and ends with 8
GRM8 - metabolic glutamate production
what gene is predisposed which ends with A in depression
RORA - circadian rhythm control
name the 6 other genes which can predispose depression
APOE PCLO TOMM40 GNB3 MTHFER SLC6A4
5 environmental factors risking depression
ethnic minority childhood maltreatment trauma prior trauma natural brain changes
3 materal environmental risk factors of depression
maternal stress
in utero infections
lack of nutrients
how do environmental stressors and serotonin transporter gene polymorphisms combine to cause depression
short allele assoc w poor serotonin functioning more likely to have it when experienced higher # of stressful life events and homozy rec
what things moderate depressive symptom severity experienced by those who have had child abuse
environmental stressors
single nucleotide polymorphisms in the brain-derived neurotrophic factor
what have twin studies shown about heritability of bipolar
MZ/DZ show higher heritability than combined data from twin studies
which gene, responsible for Wolfram syndrome, is associated with bipolar
WFS1 as comorbid with psychiatric disorders
what gene is associated with the rapid cycling of bipolar
RORB
what gene responsible for cortisol actions is associated with bipolar
CRH
what gene related to stress is associated with bipolar
encodes binding protein aiding glucocorticoid receptor heterocomplex which regulates cortisol effects of stress
3 other biological causes of bipolar
neurochemical changes
brain damage
hippocampus neurogenesis suppression
how can increasing prefrontal cortex activity treat bipolar symptoms
by decreasing subgenual anterior cingulate cortex activity
what does the prefrontal cortex do to cause negative emotional responses
inhibit the amygdala
environmental risk factors of bipolar
IBS
head injury
perinatal infection
in GxE, how does COMT relate to bipolar
responsible for breaking down dopamine, serotonin, and noradrenaline and risk depends on alleles and # stressful live events
in GxE, how does BDNF relate to bipolar
MET carriers of BDNF had more severe, earlier onset of bipolar when experienced child abuse
psych explanations of bipolar
negative explanatory style, learnt helplessness, gender differences
socio-cultural explanations of bipolar
traumatic life events, cultural expectations, and depress-evoked responses
how does the neurochemistry of bipolar and depression relate to stress hormones
higher cortisol/CSF
lower hippocampus and PFC volume in depressed
injecting CRH in rats causes depressive symptoms
how do monoamines relate to depression and serotonin
post-morterms after suicide show high # 5HT receptors
depleting tryptophan reduced 5HT causing lowered moods since it’s a precursor protein
which drug treatments working on serotonin have a positive effect on depression
MAOA inhibitors, tricyclics which block reuptake, SSRIs which are more selective than tricyclics
in what season are most depressed people who commit suicide born in
summer
how does BDNF relate to depression and bipolar
stress reduces levels but SSRIs increase levels through neural plasticity so don’t work straightaway
why are some atypical antipsychotics partial agonists
have a high affinity for particular receptors but activate it less than norma;
in what pathways are D2 receptors blocked by typical APs
all
what receptors do atypical APs act on
D2 and serotonin receptors on DA neurons to counterbalance D2 blockage
how do MAO inhibitors work to treat depression
inhibit MSO enzymes so DA, 5HT, NA broken down less but can cause hypertensive reactions
how do tricyclics work to treat depression
inhibits NA, 5HT reuptake and prolongs PSPs but affects cholinergic system and linked to dementia
how do SSRIs work to treat depression
inhibits 5HT or 5HT and NA reuptake with fewer non-specific effects but fewer side effects
another example of a drug treatment for depression
serotonin noradrenaline reuptake inhibitors
how does electroconclusive therapy for depression work
electrodes induce seizure activity which helps suicidal patients as relieves thoughts quickly by increasing seizure threshold and decreasing brain activity
transcranial magnetic stimulation works as a treatment how
localised magnetic field induces electrical current when applied to the prefrontal cortex without causing cognitive deficits
how does direct brain stimulation work as a depression treatment
electrodes implanted in subgenual anterior cingulate cortex and directed towards the nucleus accumbens to increase dopamine release
how does REM sleep deprivation work
wake up when patient is in REM
how does slow-wave sleep deprivation work
suppressing slow waves without waking person up to reduce time spent in REM
how does total sleep deprivation work
helps facilitate medication effects as brain produces depressogenic chemical when asleep but not awake
3 examples of bipolar drug treatments of which lithium is an example of one
mood stabilisers
anticonvulsants
antipsychotics
how does lithium treat bipolar
treats manic phase so depression doesn’t occur and allows joy/sadness to be felt without any LT effects for intellect and emotion
what are lithium’s biological effects
serotonin stabilised, increases neuroprotective proteins to reduce cell death, and grey matter increased
