Schizophrenia: Historical Perspective and Clinical Features Flashcards
Define psychotic?
Presence of hallucinations, delusions, limited number of behavioural abnormalities (e.g. gross exciteent, overactivity, psychomotor retardation, catatonic)
Schizophrenia: First characterised diagnostic features?
4As
Associations (loose e.g. incoherent speech)
Affect (i.e. how a mood presents- flat)
Autism (social withdrawal)
Ambivalence (+ve/-ve feelings)
List types of schizophrenia symptoms
Positive (halluc, delusions, thought disorder)
Negative (expressive deficits, withdrawal)
Disorganisation (thought disorder)
Affective disturbance (hopelessness, hypomania)
Disturbed behaviour (social withdrawal, depressed features)
Impaired social cognition (lack of empathy)
Neurocognitive function (attention, memory, exec function)
“Classical” schizophrenia subtypes?
NB: these categories are seen as being overalapping and have questionable validity/clinical relevance
- Paranoid: persecutory/grandiose delusions, derogatory auditory hallucinations
- Hebephrenic: disorganisation syndrome (formal thought disorder), affective flattening/incongruity, bizarre behaviour
- Catatonic: multiple motor, volitional + behavioural disorders, stupor and excitement
- Simple: insidious but progressive impoverishment of mental life without development of florid sympsoms
Outline the 2 syndrome model of schizophrenia
Type 1 positive symptoms acute good response to meds reversible no intellectual impairment increased DA receptors
Type 2 negative symptoms chronic poor response to meds irreversible? intellectual impairment cell loss + structural damage
Outline Liddle’s Three Syndromes for schizophrenia
- Psychomotor poverty: speech poverty, decreased spontaneous mvmt, unchanging facial expression, paucity of expressive gesture, affective non-response, lack of vocal inflections
- Disorganisation syndrome: inappropriate affect, poverty of speech content, tangentiality, derailment, pressure of speech, distractibility
- Reality distortion: voices speak to patient, delsuions of persecution, delusions of reference
Risk of death in schizophrenia?
Increased compared to general population (2.5x)
This gap seems to be increasing
[mortality data comparable to heavy smokers]
Main factors why schizophrenia pts have worse physical health (and increased mortality)?
Risk associated w/
- Diabetes: higher risk of glycaemic abnormalities with FEP
- CVD: share same path features: ox. stress, neuroinflamm, mitoch dys
- Antipsychotic treatment
Other contributors why schizophrenia pts have worse physical health (and increased mortality)?
- lack of access to preventative care
- suboptimal cardiac care
- unhealthy lifestyle
- smoking
- social deprivation
- poor diet
- poor compliance with meds
- high level of substance use
Schizophrenia contributors for genetic aetiology
- Susceptibility genes: SNPs, CNVs, rare variants; Neuregulin 1, Dysbindin, DISC1
- Advancing paternal age
- MHC variation: excessive or insufficient synaptic pruning controlled by C4
Possible evidence between cannabis and later psychosis?
40% increase risk in psychosis in individuals who had ever used cannabis
UK prison inmates: cannabis users < 16 -> x2 risk of functional psychosis
Swedish cohort study: heavy use age 18 -> x6 risk of schizophrenia
See: Dunedin, Christchurch, Munich
Reverse causality of cannabis and schizophrenia- alternative theories?
Ppl experiencing early schizophrenia symptoms might turn to cannabis to self-medicate?
Possible mechanism influencing relationship between cannabis and schizophrenia?
Genetic-environmental factors:
COMT (on chr22q11) encodes catechol-o-methyltransferase, involved w/ DA metab in synapse
Common mutation is valine -> methionine -> less active enzyme
MM/MV: cannabis doesn’t increase schiz risk
VV: cannabis does increase schiz risk
Disease progression of schizophrenia?
- Premorbid (asymptomatic)
2, prodromal symptoms (sleep disturbance, paranoia, withdrawal) - progression (episodes of psychosis)
- stable/relapsing (more stable w/ treatment)
Define DUP?
Duration of untreated psychosis
Importance of DUP?
Longer DUPs associated w/ poorer response to meds and poorer symptomatic + functional outcomes during first several years of treatment