Psychosis Flashcards
Define psychosis
The thoughts, affective response or ability to recognise reality and the ability to communicate and relate to others is grossly impaired with the capacity to deal with reality
What are the classic characteristics of psychosis?
Hallucinations
Delusions
Disorders of form of thought
Lack of insight
When can psychosis occur?
- Organic conditions
- Manic depressive
- Substance use
- Dementia praecox
What signs are involved in psychotic experiences?
- Hallucinations
- Ideas of reference
- Delusions
- Passivity
- Loosening of associations
- Neologisms
- Circumstantiality
- Changing and punning
- Thought interference
What are hallucinations?
Occurs in the absence of stimuli but has the same qualities as normal perception
What is meant by ideas of reference?
Innocuous, day to day events that a person with psychosis will think are significant to them
Give an example of ideas of reference
Message in the news
Number plates
What are delusions?
Abnormal belief held to absolute conviction, usually false and not amenable to social or cultural beliefs
What is the difference between primary and secondary delusions?
Primary - no preceding event
Secondary - derived from a preceding event e.g hallucination
Describe passivity phenomena
Behaviour is experienced as being controlled by an external agency rather than the individual
Describe loosening of associations
Speech is muddled and difficult to follow, cannot be clarified with no logical connection
What are neologisms?
Patient makes up a new work/phrase with no accepted meaning
What is another name for loosening of associations?
Knights move thinking
Name four types of thought interference
- insertion
- withdrawal
- broadcasting
- blocking
What illicit substances can cause psychosis?
Legal highs , amphetamine, cannabis
Which prescription drugs can cause psychosis?
Levodopa, steroids, anti-malarial, anti-psychotic, anti-convulsants, anti-depressants
What causes psychosis on withdrawal?
Alcohol
Benzodiazepines
How does a drug induced psychosis present?
Florid symptoms - visual or tactile hallucinations which should resolve on cessation of the drug (takes up to 4 weeks)
How will depressive psychosis present?
Delusions of worthlessness, guilt, nihilism, derogatory hallucinations usually auditory
Describe manic psychosis
Delusions of grandeur and auditory hallucinations
What is delirium?
Acute disorder of the mental processes whereby mental confusion is accompanied by a physical condition
What are the symptoms of delirium?
- Disorientation in time and place
- Delusions
- Hallucinations
- Insomnia
- Agitation
- Worse at night
- May have lucid periods
What are the three types of passivity?
of volition - made actions
of affect - made feelings
of impulse - made urges
What is your lifetime risk of schizophrenia?
1%
Which gender and class are more at risk of schizophrenia?
Men and those of lower socioeconomic class
What is the average age of onset of schizophrenia?
Males - 15-25 years old
Females 25-35 years old
What percentage of cases of schizophrenia are inherited?
80%
What environmental factors can contribute to schizophrenia?
Obstetric complications (2nd trimester virus, pre-eclampsia, hypoxia? Childhood CNS infection Early Cannabis use Urban upbringing Psychological stress
What neurochemical changes can be seen in schizophrenia?
Changes in dopamine signalling
What histological changes can be seen in schizophrenia?
Lack of gliosis
What structural changes can be seen in schizophrenia?
Ventricular enlargement and altered CSF flow
Decrease in healthy white matter associated with cognitive decline
Reduced frontal lobe volume (and grey matter) Reduced grey matter in the temporal cortex.
State the first rank symptoms
- 3rd person auditory hallucinations that give a running commentary
- Thought insertion, broadcast, removal
- Passivity phenomena
- Delusional perception
What is delusional perception?
Belief attached to a real perception
State the symptoms in ICD10 that only require one for diagnosis
Thought interference Delusional perception Hallucinatory voices Persistent delusions One for at least one month
State the symptoms in ICD10 that require two for diagnosis
Persistent hallucinations occurring everyday
Incoherent/irrelevant speech due to neologisms/breaks/interpolations
Catatonic behaviour
Negative symptoms
What are the positive symptoms?
- hallucinations
- delusions
- passivity phenomena
- disorder of form of thought
What are the negative symptoms?
- reduced speech
- reduced motivation
- reduced interest/pleasure
- reduced social interaction
- blunting affect
Describe paranoid schizophrenia
Most common type (80%)
Mainly first rank symptoms (hallucinations and delusions of self)
Describe hebephrenic schizophrenia
Disorganised, thought disorder with odd behaviour and bizarre delusions, intellectual disorientation
Describe catatonic schizophrenia
Predominant mood disorders (odd postures), mutism, stupor, resistance to command/attempts to be moved = negativism or automatic command
Name four other types of paranoid psychoses
- persistent delusional disorder
- schizotypal disorder
- acute and transient psychotic disorder (<1month)
- schizoaffective disorder (first rank +depression or mania)
Name the poor prognostic indicators
Poor pre-morbid adjustment Insidious onset Early onset Long duration of untreated psychosis Cognitive impairment Enlarged ventricles
Name good prognostic indicators
Shorter time of untreated psychosis Older onset Female Marked mood disturbance Family history of mood disorders
How are antipsychotic drugs classified?
1st, 2nd and 3rd generation
Give examples of first generation anti-psychotics
Haloperidol and flupenticol
Give examples of second generation anti-psychotics
Clozapine, risperiodone, olanzapine, quetiapine
Give examples of third generation anti-psychotics
Aripiprazole (dopamine partial agonist)
What pathology in relation to dopamine is present in schizophrenia?
Excess and aberrant firing of dopaminergic neutrons in schizophrenia
Name the five dopamine pathways
- mesolimbic (leads to first rank symptoms)
- mesocortical (links to higher brain function)
- nigrostriatal (voluntary movements)
- tuberoinfundibular (hypothalamus and pituitary)
- hypothalamospinal (into PNS)
How many dopamine receptors are there and which do you want to target?
5
Aim to affect D2- limbic and mesolimbic pathways
What other receptors are involved?
ACh, 5HT, Histamine, NAdr
What percentage of dopamine blockage is the target?
60-80% for minimal side effects and maximal clinical effects
What are the four key classes of side effects?
- extra-pyramidal
- neuroleptic malignant syndrome
- hyperprolactinaemia
- akathesia/restless legs
What extra-pyramidal side effects can occur?
Acute dystonia
Parkinsonism
Tardive Dyskinesia
Describe acute dystonia
Onset in minutes, presents with energetic increased tone, tongue protrusion, torticolis and oculogyric crisis (all eye muscles contract at the same time)
Describe tardive dyskinesia
Long term, often permanent involuntary repetitive pro-facial movements (blinking, grimacing, pouting), may involve limbs or trunk and occurs after decades of treatment
How are extra-pyramidal side effects treated?
Aim to balance ACh and dopamine by anti-cholinergic drugs such as procyclidine
What is neuroleptic malignant syndrome?
Rare, onset over hours and fatal if untreated in 20-30%
Gradually increasing tone, pyrexia and autonomic instability - pulse/BP leads to rhabdomyolysis and acute renal failure
How is neuroleptic malignant syndrome investigated?
CK - elevated
How is neuroleptic malignant syndrome treated?
Stop drug, rapid cooling and renal support, muscle relaxant and dopamine agonist - may need induced coma
dantrolene, bromocriptine
How does hyperprolactinaemia present in women?
Galactorrhoea, reduced libido, arousalm organism, amenorrhoea and anovulation
How will hyperprolactinaemia present in men?
Gynaecomastia, ED, oligospermia, reduced libido
How will hyperprolactinaemia present in both sexes?
Reduced bone density leading to osteoporosis
Describe akathesia
Affects 20% of patients within days to weeks of treatment
Pacing, rocking from foot to foot, unable to sit/stand, restless legs, agitation and high risk of suicide
What is the treatment for akathesia?
Beta blocker or benzodiazepine
Other than dopaminergic what other side effects can occur with anti-psychotics?
Anti-cholinergic
Serotonergic
Anti-adrenergic
Others - long QT, hepatotoxicity, photosensitivity
What is the best anti-psychotic?
Clozapine particularly for negative symptoms it also has antisuicidal properties
What are the side effects of clozapine?
Agranulocytosis Myocarditis Constipation leading to perforation Weight gain (10kg in 3 months) Sedation Sialorrhoea
How often does a patient with clozapine need monitored?
Weekly for first 6 months
Biweekly for next 6 months
Monthly thereafter
How long should an anti-psychotic be tried before it is deemed unsuccessful?
6-8 weeks
What alternative administration can be considered in some patients?
Long acting depot - IM, deltoid or gluteal weekly to 3 months gives better stability
What generation of drugs should be tried first?
2nd generation
What is the function of the D1 receptor family?
Stimulates cAMP
What is the function of the D2 receptor family?
Inhibit adenylyl cyclase
Inhibit voltage gates calcium channels
Open potassium channels
Which set of dopamine receptors are present in the pituitary?
D2 important for pharmacology
What is the difference between the effect of subcortical and mesocortical dopamine?
Subcortical hyperactivity causes psychosis
Mesocortical hyperactivity causes negative/cognitive symptoms
What three proteins are involved in schizophrenia?
Neuregulin
Dysbindin
DISC-1
What does neuregulin do?
Signalling protein that mediates cell-cell interactions and plays critical roles in the growth and development of multiple organ systems
What does dysbindin do?
Essential for adaptive neural plasticity
What is the function of DISC-1?
Neuritic outgrowth and cortical development through its interaction with other proteins
