Schizophrenia Flashcards
Why is schizophrenia important?
- Has an early onset
- Prevalent
- Disabling and chronic
What are some features of schizophrenia?
- Mental state that is out of touch with reality
- Abnormalities of perception thought & ideas
- Profound alterations in behaviour (bizarre and disturbing alienation)
Describe the prevalence of schizophrenia
- Affects up to 1% of the population
- no significant influence of culture, ethnicity, background socioeconomic groups
- Increased in urban areas
- Difference between sexes
- A chronically disabling condition: responsible for great deal of the populations morbidity
How can the prevalence of schizophrenia be spotted?
- Before the illness is recognised, there is often a phase in late teenage years associated with social isolation, interest in fringe cults and social withdrawal
List the 3 classes of schizophrenia symptoms
- Positive
- Negative
- Cognitive
- Two or more of these symptoms must persist for at least 6 months to be classed as schizophrenic
List the positive symptoms of schizophrenia
- Hallucinations
- Delusions
- Disorganised speech
- Movement disorders
List the negative symptoms of schizophrenia
- Social withdrawal
- Anhedonia
- Lack of motivation
- Slurred speech
List the cognitive symptoms of schizophrenia
- Impaired working memory
- Impaired attention
- Impaired comprehension
Describe some features of hallucinations
- Perception experience without stimulus
- Most commonly auditory
- Patient hears voices talking to/about them or giving a running commentary
- patients may engage in a dialogue with voices or obey their commands
Describe features of delusions
- A fixed unshakable belief
- Not consistent with cultural/social norms
- Often paranoid or persecutory
- Passivity of thoughts and actions
What is a motor,volitional and behavioural disorder?
Peculiar forms of motility, stupor, mutism, stereotypy, mannerism, negativism, spontaneous automatism, impulsivity
List some symptoms of Motor, volitional and behavioural disorders
- Stereotypies: purposeless, repetitive acts
- Bizzare 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 hypactivity
- Impulsive behaviour: Violent acts: murder without reason
What is a 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
List some symptoms of formal thought disorder
- Disturbances in thinking: Unintelligible speech
- Derailment of speech
- Loosening of associations; failure to follow train of thought to its conclusion
- Poverty of speech (speech fails to convey sense/information): Manifests as distorted or illogical speech
What is social withdrawal?
List some symptoms
- 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 is Cognitive deficits?
List some symptoms
- 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 an insight in regards to schizophrenia?
- An understanding of what is wrong
- Insight lacking in schizophrenia
- Patients usually do not accept that anything is wrong or that treatment is necessary
List the 4 phases of schizophrenia (LO)
- The prodrome: Late teens/early 20’s 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
Discuss the genetic causes of schizophrenia
- In monozygotic twin studies, there is a 50% chance of developing schizophrenia if one twin is diagnosed
- Between dizygotic twins, there is a 14% change of developing schizophrenia if one twin is diagnosed
Describe candidate genes as a genetic cause for schizophrenia
- Sickle cell disease, cystic fibrosis, colour blindness
- We know the exact genetic abnormalities that lead to these disorders
List some pregnancy/birth complications as nurture effects for schizophrenia
- Low birth weight
- Premature birth
- Asphyxia during birth
- These all causes early life stresses
Describe stress as a nurture effect for schizophrenia
- Moving country
- Early life bereavement
- Loss of job/home/relationship
- Physical/emotional/sexual abuse
List the causes of nature vs nurture for schizophrenia
Nature
- Scz isn’t directly inherited but can run in families
- Candidate risk genes: Gene deletions/mutations
Nurture
- Pregnancy/birth complications
- Stress
- Drug use
List some Pathophysiology causes of schizophrenia
- Dopamine hypothesis
- Brain structure differences
- Hypofrontality
- NMDA receptor hypofunction
- Oxidative stress
- Neuroinflammation
Discuss the dopamine theory causing scz
- Dopamine release (Amphetamine) produces scz
- Amph enhances dopamine release in schizophrenics more than controls which makes the disease worse
- D2 agonists produce stereotyped behaviour (not D1)
- Reserpine depletes dopamine, controls positive symptoms
- Strong correlation D2 blocking activity & antipsychotic action
- Dopamine release only in mesolimbic, mesocorrical not nigrostriatal
Discuss the dopamine theory against causing scz
Evidence against
- No clear change in CSF HVA concentration
- No change in DA receptor in drug free patients
(Increased D2 receptors in samples attributed to drug treatment
List some brain structure abnormalities in twins with scz compared with healthy twins
- Overall brain size slightly smaller
- Reductions in grey matter
- Enlarged lateral ventricles, smaller hippocampus
- Not all people with scz have such profound structural brain differences
What is hypofrontality?
Reduced blood flow to the frontal cortex causing Reduced activity
Describe NMDA receptor hypofunction?
- NMDA antagonists (Ketamine/phencyclidine)
- ã [glutamate] and glutamate receptor density in prefrontal cortex
- Transgenic mice with ã NMDA receptor expression
- Stereotyped behaviour & ã social interaction, responsive to antipsychotics
What is the serotonin theory of causing scz
Main current theory
- Over stimulation of mesolimbic D2 receptors
- Hypoactivity of frontal cortical D1 receptors
- Reduced prefrontal glutaminergic activity
- Serotonin involved
What types of treatment could be reviewed for scz
- Pharmacological treatments
- Cognitive behavioural therapy (CBT)
- Electroconvulsive therapy (ECT)
What are the main dopamine pathways?
- Tubero hypophyseal pathway
- Mesocortical pathway
- Mesolimbic pathway
- Nigrostiatial pathway
Involved in: Movement,cognition,emotions,Motivation,Reward
Compare typical with atypical antipsychotics
Typical
- Also known as first generation
- First developed in the 1950’s
- Mainly antagonise D2 receptors
Atypicals
- Also known as second generations
- First developed in the 1980’s
- Mainly antagonise D2 & 5 HT2A receptors
List the affects of the muscarinic blockade with the use of antipsychotics
Beneficial for treating extra pyramidal side effects
- Dry mouth
- Blurred vision
- Constipation
- Urinary retention
List the affects of the ã adrenoceptor blockade with the use of antipsychotics
- Postural hypotension
- Nasal congestion
- Hypothermia
List the affects of the D2 receptor blockade with the use of antipsychotics
Nigro-striatal -> Basal Ganglia (striatum) -> movement disorders
- Parkinsonism
- Dystonia
- Dyskinesia
- Tardive
List the affects of the D2 receptor blockade in regards to the pituitary gland with the use of antipsychotics
Has endocrine effects
- Breast swelling
- Lactation
- Impotence
List the affects of the D2 receptor blockade in regards to the mesolimbic system with the use of antipsychotics
Goes to the Cortex limbic system which causes psychological effects
