3. Schizophrenia & Related Disorders Flashcards
What is schizophrenia?
What is it characterised by?
Mental illness that affects cognition, emotion and perception
It is characterised by 4 types of symptoms.
1. Positive symptoms (presence of mental features not normally present)
- delusions and hallucinations
2. Negative symptoms (reflects diminished or loss of normal emotional and psychological function)
- affective flattening
- alogia
- avolition
- anhedonia
- asociality
- apathy
3. cognitive symptoms
- impairment in attention, reasoning and judgement
4. disorganised symptoms
- disturbances in thinking, speech, behaviour and incongruous affect
Risk factors of schizophrenia
- Family history of schizophrenia (most important risk factor)
- neuregulin 1 gene on chromosome 8
- dysbindin gene on chromosome 8 and chromosome 22q11 - Antenatal/Perinatal
- influenza infection
- maternal measles
- rubella infection
- premature rupture of membranes
- preterm labour
- low birth weight
- usage of resuscitation during delivery
- foetal hypoxia during delivery - Biological
- head injury (a/w paranoid schizophrenia)
- epilepsy
- temporal lobe disease
- misuse of cannabis - Demographics
- male patients have more severe disease
- advanced paternal age at the time of birth - Physiological
- stressful life events (tends to ppt first episode psychosis)
- high expressed emotions in the family (Over-involvement, Critical comments, Hostility from family members more than 33h/week)
Prevalence of schizophrenia among relatives of schizo patients:
Child of 1 affected parent
13%
Prevalence of schizophrenia among relatives of schizo patients:
Child of 2 affected parents
46%
Prevalence of schizophrenia among relatives of schizo patients:
Siblings
10%
Prevalence of schizophrenia among relatives of schizo patients:
General population
0.5-1%
Prevalence of schizophrenia among relatives of schizo patients:
Parents of affected child
5.6%
Prevalence of schizophrenia among relatives of schizo patients:
Grandchild
3.7%
Prevalence of schizophrenia among relatives of schizo patients:
Dizygotic twin of other affected twin
Monozygotic twin of other affected twin
14%
46%
What is a protective factor of schizophrenia?
Rheumatoid arthritis
Gross pathological changes in schizophrenia
Atrophy of the prefrontal cortex and temporal lobe
Neurochemical abnormalities
Increased dopamine in the mesolimbic pathway and the increased levels of dopamine cause schizophrenia
2 serotonin pathways are affected in schizophrenia
Excess serotonin produced by the 2 pathways causes a reduction in the availability of dopamine which can give rise to negative symptoms of schizophrenia
Second generation antipsychotics:
1. 5HT2A antagonist -> causing an increase in dopamine -> relieves negative symptoms
2. D2 antagonist -> relieves positive symptoms
Schneider’s First Rank Symptoms of Schizophrenia
ABCD
Auditory hallucinations
- 2nd (voices speak to YOU) or 3rd person (voices speak among themselves)
- Thought echo, running commentary, voices discussing patient
- Somatic (bodily, tactile) hallucinations
- Command hallucinations (not part of the FRS but please rmb to ask)
delusions of thought interference
- Thought Broadcasting, insertion and withdrawal
delusion of Control and passivity
- A person believes others are trying to control their impulses, feelings, thoughts or behaviours
Delusion perception
DSM-5 Diagnostic Criteria: Schizophrenia
Presence of >/= ___ of the following symptoms (at least 1 of which must be 1, 2 or 3)
Continuous impairment over a period of at least ___ months
- Delusions
- Hallucinations
- Incoherent and disorganised speech
- Disorganised or catatonic behaviour
- Negative symptoms/diminished emotional expression
Presence of >/= 2 of the following symptoms (at least 1 of which must be 1, 2 or 3)
Continuous impairment over a period of at least 6 months
Symptoms must not be due to substance use or underlying medical condition
Deterioration in occupational and social function is compulsory
Schizophreniform Disorder
Presence of >/= 2 of the following symptoms (at least 1 of which must be 1, 2 or 3) for a duration of between 1-6 months:
- Delusions
- Hallucinations
- Incoherent and disorganised speech
- Disorganised or catatonic behaviour
- Negative symptoms
Brief Psychosis
The individual should be able to…
Presence of >/= 2 of the following symptoms (at least 1 of which must be 1, 2 or 3) for a duration of between 1 day to 1 month:
- Delusions
- Hallucinations
- Incoherent and disorganised speech
- Disorganised or catatonic behaviour
The individual should be able to return to premorbid functional level after the course of the illness.
Brief psychosis could occur…
either in the presence or absence of stressors
Differentials for psychogenic polydipsia
Nephrogenic DI (serum sodium will be high)
SIADH (low urine output)
Difference between schizophrenia, schizophreniform disorder and brief psychosis is
Duration and impairment of function
Poor prognosticating factors of schizophrenia
Male
Single
Past psychiatric history
Family history of schizophrenia
Early onset
Negative symptoms
Poor response to treatment
Long duration of untreated psychosis
Favourable prognosticating factors of schizophrenia
Female
Married
Precipitated by stressful life events
Family history of mood disorders
Paranoid type
Positive symptoms
Good response to treatment
Short duration of untreated psychosis
Differentials of Schizophrenia
TRO psychoses that could be 2’ to physical morbidity or substance use
- Misuse of substances (alcohol, stimulants, hallucinogens, glues or sympathomimetics)***
- Medications (steroids, anticholinergics, anti-parkinson drugs)***
- Organic causes
- Severe depression or mania with psychotic features***
- Delusional disorders
2 types of anti-psychotics and examples
1st generation antipsychotics:
Haloperidol
Chlorpromazine
Trifluoperazine
2nd generation antipsychotics:
Risperidone
Quetiapine
Olanzapine
Clozapine
MOA of the anti-psychotics
1st generation anti-psychotics: dopamine receptor antagonists in mesolimbic pathway (good relief of +ve sx)
2nd generation anti-psychotics: serotonin and dopamine receptor antagonists
Indications for 1st/2nd generation anti-psychotics
Schizophrenia
Schizoaffective disorder
Substance-induced psychosis
Personality disorder with psychotic features
Mood disorders with psychotic features
Contraindications of first gen anti-psychotics
PARKINSON disease
Lewy body dementia
Elderly prone to developing extrapyramidal side effects
Side effects of first gen anti-psychotics
- Extrapyramidal side effects (due to blockade of D2 receptors in basal ganglia - mesolimbic pathway):
- Acute Dystonia
- Pseudo-parkinsonism
- Akathisia - Tardive Dyskinesia (due to D2 receptor hypersensitivity):
- Abnormal involuntary muscle movements - Sedation (due to antihistamine activity)
- Secondary negative symptoms (due to blockade of D2 receptors in mesocortical pathway)
- Sexual - Galactorrhea, Amenorrhea, Gynecomastia, no libido (due to dopamine blockade in tuberoinfundibular pathway -> hyperprolactinemia)
- QTc prolongation
- Neuroleptic Malignant Syndrome (rare)
Haloperidol
MOA
Indications
S/E
MOA: potent D2 blocker -> lowers level of activity within the nigrostriatal pathway
Indications: Schizo (+ve sx), delirium, rapid tranquillisation (IM)
S/E: ESPEs
Chlorpromazine
S/E
Cholestatic jaundice
Cataract
Postural hypotension
ST depression on ECG
Increase in seizure
Skin rashes
MOA for 2nd gen antipsychotics
D2 blockade in mesolimbic pathway & 5HT2A receptor blockade
Side effects of 2nd gen anti-psychotics
Lower risks of EPSEs
Higher risks of metabolic syndrome/obesity/diabetes/weight gain
Risperidone S/E
@ higher doses: Prone to EPSEs and hyperprolactinaemia but ok at lower doses
- most common due to most balanced in terms of cost, S/E profile and efficacy
Olanzapine
C/I
S/E
C/I: stroke, diabetes, obesity, narrow angle glaucoma
S/E: Weight gain (highest risk), anticholinergics S/Es
