Schizophrenia Flashcards
(35 cards)
What is schizophrenia?
State of distorted perception, not limited to visual info.
Why is schizophrenia the most important psychotic disordeR?
Early in onset
Prevalent
Disabling and chronic
What are the 4 phases of Schizophrenia?
1.The Prodrome
Late teens/early twenties: often mistaken for depression or anxiety
Can be triggered by stress
- The Active/Acute Phase
Onset of positive symptoms
Differentiation of what is and isn’t real becomes difficult - Remission
Treatment –> return to ‘normality’ - Relapse
What are the 3 classes into which schizophrenia can be grouped?
POSITIVE (an increase in abnormal behaviours):
- Hallucinations (e.g. visual, auditory)
- Delusions
- Disorganised thought/speech
- Movement disorders
NEGATIVE (an absence of normal behaviours):
- Social withdrawal
- Anhedonia (inability to feel pleasure at pleasurable activities)
- Lack of motivation
- Poverty of speech
- Emotional flatness
COGNITIVE (problems with thought processes):
- Impaired working memory
- Impaired attention
- Impaired comprehension
Two or more of these symptoms must persist for at
least 6 months to be classed as schizophrenia.
What are hallucinations?
Perception experienced without stimulus
What are delusions?
A fixed/unshakable belief, not consistent with cultural/social norms.
What are motor, volitional and behavioural disorders?
Peculiar forms of motility, stupor, mutism, stereotypy, mannerism, negativism, spontaneous automatism, impulsivity
Stereotypies: purposeless, repetitive acts
Bizarre postures, strange mannerisms
Altered facial expression – grimacing
State of catatonia – motionless, mute, expressionless, uncomfortable or contorted postures
State of catalepsy – waxy flexible
Bouts of extreme hyperactivity (destructiveness; walk around naked)
Impulsive behaviour – violent acts; murder w/o reason
What is formal thought disorder?
A disorder of conceptual thinking, reflected in speech that is difficult to understand and rapid shifts from one subject to another. New words are invented (neologisms).
What is social withdrawal?
Patients withdraw from their families and friends and spend a lot of time on their own.
Lack of initiative or motivation
Do not want to do anything.
No longer interested in things that used to interest them.
What are cognitive deficits?
Deficits in SELECTIVE attention, problem solving and memory
Blunted affect Decreased responsiveness to emotional issues. Incongruous affect. Expression of affect inappropriate to circumstances.
What is insight?
An understanding of what is wrong.
Insight lacking in schizophrenia.
Patients usually do not accept that any thing is wrong or that treatment is necessary.
What is the aetiology of schizophrenia?
There are genetic factors:
- SCZ isn’t directly inherited, but can ‘run in families’
- ‘Candidate’ risk genes: gene deletions, gene mutations
There are environmental factors:
- Pregnancy/birth complications
- Stress
- Drug use
It is due to both nature and nurture that schizophrenia develops.
What are some of the candidate genes for schizophrenia?
Examples of some of these genes is:
- COMT
- DISC1
- GRM3
Possessing these abnormal genes does not mean you will definitely get schizophrenia – similarly, some people who have schizophrenia do not have these genetic abnormalities.
How can pregnancy/birth complications cause schizophrenia?
A Finnish study reported a spike in schizophrenia for people who were foetuses during the 1957 influenza epidemic. Thus, pregnant women in the UK are advised to be vaccinated against seasonal flu.
Low birth weight, premature birth, and asphyxia during birth are all causes of early-life stress (stemming from birth complications).
Give some examples of stress that can cause schizophrenia.
- MOVING COUNTRY: Swedish cohort 1 first-degree relative further increased risk
- LOSS OF JOB/HOME/RELATIONSHIP
- PHYSICAL/EMOTIONAL/SEXUAL ABUSE
The mechanism by which stress may trigger schizophrenia is unknown.
How can drug abuse lead to schizophrenia?
Continued cannibas use during early life for ~15 years has been shown to increase the risk of schizophrenia development.
Other drugs that could are:
- amphetamine
- cocaine
- LSD
What are the hypotheses for the pathophysiology of schizophrenia?
There is the:
- dopamine hypothesis
- glutamate hypothesis
There are many other hypotheses:
- Brain structure differences
- Hypofrontality
- Inhibitory interneuron dysfunction
- Kynurenic Acid
- Oxidative Stress
- Immune System Abnormalities
What are the main dopamine pathways?
MESOCORTICAL PATHWAY: cognitive control and motivation and emotion
MESOLIMBIC PATHWAY: reward
NIGROSTRIATAL PATHWAY: movement
TUBEROHYPOPHYSEAL PATHWAY: prolactin release
Describe the dopamine hypothesis.
Schizophrenia is associated with abnormally high dopaminergic transmission from mesolimbic pathways.
However, there is no conclusive evidence that dopamine levels are increased in schizophrenia.
What are some theories regarding dopamine and the symptoms of schizophrenia?
Positive symptoms – hyperDAergic in mesolimbic system (increase D2 )-but D2 antagonists do the same
Negative symptoms – hypoDAergic activity in mesocortical system (decrease D1 )=>decrease cognition
D4 involved? But selective D4 antagonists not effective
What is the pharmocological evidence for dopamine hypothesis?
DA release (amphetamine) produces ‘schizophrenia’
DA release only in mesolimbic, mesocortical NOT nigrostriatal
D2 agonists produce stereotyped behaviour (not D1)
Reserpine depletes DA – controls positive symptoms
Strong correlation D2 blocking activity & antipsychotic action
Amphetamine enhances DA release in schizophrenics more than controls which makes the disease worse
What is some evidence against the dopamine hypothesis?
No clear change in CSF HVA concentration
No change in DA receptors in drug-free patients (Increased D2 receptors in p-m samples attributed to drug treatment)
What are some brain structural differences in schizophrenic brains vs normal brains?
Overall brain size slightly smaller
Reductions in grey matter
Enlarged lateral ventricles – smaller hippocampus
*Not all people with schizophrenia have such profound structural brain differences
What is hypofrontality?
Reduced blood flow to the frontal cortex
Reduced activity in frontal cortex?
