schizophrenia Flashcards
What is the definition of schizophrenia by ICD-10?
a severe and enduring disorder, with fundamental and characteristic distortions of thinking and perception, and affects that are inappropriate or blunted. clear consciousness and intellectual capacity are usually maintained, although cognitive deficits may evolve in the course of time
+ accompanied by high levels of social dysfunction, inability to maintain employment, depression and suicide
What are the different symptoms in schizophrenia?
- -> positive symptoms (psychosis)
- delusions
- hallucinations
- thought disorder
- -> negative symptoms (deficit)
- flat or blunted affect and emotion
- poverty of speech (logia)
- anhedonia (inability to experience pleasure)
- associability (lack of desire to form relationships)
- avolition (lack of motivation)
- -> cognitive impairements
- particularly memory and executive function
What is the difference between hallucination and delusion?
- delusion: fixed, false belief, unshakeable by superior evidence to the contrary, and out of keeping with a person’s cultural norms
- hallucination: a perception, internally generated, in the absence of an external stimulus
What types of delusions do you see in schizophrenia?
- reference: believe things are directed at yourself when they are not
- persecution: people are out to get you
- control: people are controlling you
- bizarre and impossible
What types of hallucinations are typically seen in schizophrenia?
auditory
+ telling them to do things/ negative things about themselves, are very distressing
What is the prevalence of schizophrenia in a population?
- 10-20 per 100000 adult population per year
- UK prevalence: 0.4%
What is the modal age of onset?
Median age?
modal: 20
median: 26 (male, 29 (females)
What is the male:female ratio for schizophrenia?
1.4:4
What is the genetic risk in schizophrenia?
-7% risk in 1st degree relative
-2.3% in second degree relative
-10% dizygotic co-twins
-45% monozygotic co-twins
(SZ inherited not learned)
What is the genes involved in Sz?
- over 200
- connected to glutamate, dopamine and GABA neurotransmitter function, neuronal structures, plasticity, general synaptic function, or to inflame/immune response
What are the environmental risk involved in Sz?
- child abuse, taken into care
- cannabis or other substances misuse
- second generation of UK ethnic minority
- migration
- peri-natal oxygen deprivation, maternal starvation while in utero
- urban living, overcrowded parental separation, general deprivation as a child
How is the onset and presentation of Sz?
- preceded by subtle social and cognitive impairment, even in infant
- (prodromal/at risk state): often progresses over years from vague symptoms of depression, anxiety, insomnia or negative symptoms to vague but psychotic symptoms and then full psychosis
–> you can manage to not develop psychosis (early development or prodromal stages)
What are the diagnosis criteria under ICD-10?
- -> at least 1 first rank symptom for at least 1 month:
1. thought echo, thought insertion, thought withdrawal, thought broadcasting
2. delusions of control, influence or passivity, clearly referred to body or limb movements or specific thoughts, actions and sensations
3. auditory hallucinations giving a running commentary or discussing the patient between themselves, hallucinatory voices from parts of the body
4. persistent delusions that are completely impossible - -> OR at least 2 second rank symptoms (for a mouth)
1. other persistent hallucinations in any modality
2. thought disorder (neologisms, loosening or breaks in he train of though resulting in incoherent or irregular speech)
3. catatonic behaviour
4. negative symptoms, not due to depression or medications
What are the four major projections of the dopamine system?
- nigrostriatal pathway
2 mesolimbic pathway - mesocortical pathway
- tuberoinfundibulnar pathway
What are the components of the nigrostriatal pathway projection in Sz?
substantia nigra (SNc;A9) to striatum
- -> SNc to sensiromotor (dorsal) striatum: motor (involuntary) control
- -> SNc to associative (mid) striatum: cognition, volition, emotion