Psychiatry Flashcards
What is dementia?
An umbrella term for conditions of the brain that cause a disturbance of higher mental functions
What are the 4 main types of dementia?
Alzheimers, vascular, lewy body and frontotemporal
What are important investigations to do for dementia in primary care and why?
Bloods (FBC, U&Es, LFTs, calcium, glucose, TFTs, vitamin b12 and folate) to rule out organic, treatable causes of memory loss
What tests are used for cognitive screening in dementia?
MOCA, MMSE, Addenbrooks
What dementia is commonest?
Alzheimers
What is seen macroscopically with regard to the brain in Alzheimers?
Cerebral atrophy, particularly of the cortex and hippocampus
What is seen micoscopically with regard to the brain in Alzheimers?
Cortical plaques due to beta amyloid protein
Neurofibrally tangles caused by Tau protein
What is seen biochemically in Alzheimers?
Reduced acetylcholine
What are symptoms of Alzheimers?
Usually begin after 60 years. Memory loss with evidence of varying change in planning, reasoning, speech and orientation
How does Alzheimers progress?
Slowly and gradually over time
What is the pathogenesis of vascular dementia?
Vascular events (multiple infarcts, small vessel disease, single infarct) leading to degeneration. Commonly affects white matter, grey nucleus, thalamus and striatum
What are risk factors for vascular dementia?
Cardiovascular disease, hypertension, stroke
What are symptoms of vascular dementia?
Cognitive impairment, functional deficits, mood disorders, psychosis, delusions, emotional lability
How doe vascular dementia progress?
Stepwise degeneration
What is the pathogenesis of Lewy Body Dementia?
Spherical lewy body proteins, composed of alpha synuclin, deposited around the brain. More widespread deposits than in PD
What are symptoms of Lewy Body Dementia?
Visual hallucinations, parkinsonism, fluctuation in cognitive ability, sleep disorders, problems with multitasking
How does Lewy Body Dementia progress?
Rapidly
What is the commonest cause of dementia in under 65s?
Frontotemporal
What is the pathogenesis of frontotemporal dementia?
Neuron damage and death in the frontal and temporal lobes. Atrophy due to deposition of abnormal proteins
What are the 3 main types of frontotemporal dementia?
Picks disease, semantic and non-fluent
How does Picks disease present?
Altered emotional responsiveness, apathy, disinhibition, impulsivity, progressive decline in interpersonal skills
What are Pick bodies and how are they seen?
Spherical aggregations of Tau protein, seen on silver stain
What is the non-pharmacological management of dementia?
Behaviour management, cognitive stimulation, recreational activities
What drugs are available for Alzheimers disease?
Cholinesterase inhibitors (Donepezil, galantamine, rivastigmine) NMDA agonists (memantine) if severe
What drugs are sometimes used for lewy body dementia?
Donepezil, rivastigmine
What are side effects of cholinesterase inhibitors?
diarrhoea, vomiting, deranged LFTs, incontinence, headache, dizziness
What is the effect of depression on life expectancy?
Reduces it by 5-10 years
What are risk factors for depression?
Genetics, female gender, personality, early life experiences, stressors, physical illness, drugs
What are the core symptoms of depression?
Low mood
Anhedonia
Anergia
What are additional symptoms of depression?
Loss of confidence, guilt, recurrent thoughts of death, self harm, suicidal intent, reduced concentration, sleep disturbance, change in appetite
What is seen in MSE of a person with depression?
Appearance & behaviour = may be variable
Speech = reduced rate, volume, intonation, low pitch
Mood & affect = low
Thoughts = slow, poverty of thought, obsessions, ruminating, thoughts of guilt/death
Perception = hallucinations - mood congruent (persecutory)
Cognition = poor memory, slow thinking
Insight = typically preserved
What is dysthymia?
Chronic low mood that does not fit definition of recurrent depression. Tired and depressed for months at a time, unable to cope with demands of life
What non pharmacological treatment is helpful in depression?
CBT, sleep hygiene, physical activity
What is the first line drug for depression?
SSRI
What are examples of SSRIs?
Fluoxetine, sertaline, citalopram, paroxetine, escitalopram
How do SSRIs work?
Prevent pre-synaptic uptake of 5-HT
What are common side effects of SSRIs?
GI upset, GI bleeding, rebound anxiety as drug started, increased suicide risk, insomnia, mania
What do SSRIs interact with?
NSAIDs (use PPI), warfarin, heparin, triptans
What are discontinuation side effects of SSRIs?
Mood disturbance, restlessness, GI upset
How is switching from one SSRI to another achieved?
Withdraw the first drug then start the new drug
In fluoxetine - withdraw first then wait 4-7 days before starting new drug (long half life)
How is switching from an SSRI to venlafaxine/TCA achieved?
Cross tapering of both doses
What SSRI is used in pregnancy?
Sertraline
What SSRI is used in children?
Fluoxetine
What SSRI is used post-MI?
Sertraline
What are examples of tricyclic antidepressants?
Amitriptyline, clomipramine, imipramine
How do TCAs work?
Block serotonin and noradrenaline transporters to prevent reuptake
Also antagonise muscarinic, histamine and adrenergic receptors
What are the indications for TCAs?
Depression (2nd line)
Panic disorder, OCD
What are contraindications for TCAs?
MI, arrythmia, liver disease, porphyria, mania in bipolar
What are side effects of TCAs?
Constipation, dry mouth, blurred vision, urinary retention, sedation
How does TCA overdose present?
Arrhythmia, seizure, coma
What blood gas is seen in a TCA overdose?
Metabolic acidosis
What ECG changes are seen in TCA overdose?
Sinus tachycardia and widening of QRS
How is TCA overdose managed?
IV bicarbonate to fix acid/base balance
What drug is considered to be ‘TCA like’?
Trazadone
What are examples of monoamine oxidase inhibitors?
Phenelzine, moclobemide, isocarboxazid
How do MAOIs work?
Inhibits monoamine oxidase to prevent neurotransmitter breakdown
When are MAOIs used?
Atypical depression
What are side effects of MAOIs?
Postural hypotension, hypertensive crisis
What may precipitate hypertensive crisis in MAOIs?
Tyramine containing foods (eg. cheese, yoghurt, yeast, meat)
What are examples of SNRIs?
Venlafaxine, duloxetine
What is the mode of action of SNRIs?
Inhibit serotonin and noradrenaline reuptake
What is the indication for SNRIs?
Severe depression
When are SNRIs contraindicated?
Hypertension, arrythmia
What are side effects of SNRIs?
Nausea, dry mouth, GI upset, drowsiness, urinary retention, tachycardia, vasodilation
What is an example of a NaSSA?
Mirtazapine
What is the mode of action of mirtazapine?
Antagonist of noradrenaline, serotonin and histamine receptors
When is mitrazapine used?
2nd line in depression
What are side effects of mirtazapine?
Dry mouth, GI upset, increased appetite and weight gain, sedation, agranulocytosis
What are symptoms of mania?
Elevated mood, increased energy levels, overactivity, pressure of speech, decreased need for sleep, disinhibition, grandiose ideas, tasking risks, overspending, delusions, hallucinations
What is hypomania?
Milder elevation of mood with no psychosis
What is rapid cycling of mood?
4 or more episodes of mania in 1 year. Can be interspersed with periods of wellness
How is bipolar disorder defined?
Two or more episodes of mania +/- depression
What is the average age of onset of bipolar disorder?
21
What is bipolar 1?
More pronounced mania
What is bipolar 2?
Hypomania, severe depression more common
What are risk factors for bipolar disorder?
Genetics, stressors, childbirth, drugs
What is the lifetime risk of suicide with bipolar disorder?
12-15%
What symptoms are mood stabilisers generally better at treating in bipolar?
Manic rather than depressive
What are examples of drugs used for mood stabilising?
Litihium, lamotrigine, sodium valproate, olanzapine, aripiprazole
How does lithium work?
Mechanism unclear - may interact with cation transport, glutamate or cAMP
What are indications for lithium?
Bipolar disorder, treatment resistant depression, schizoaffective disorder
What are cautions for lithium?
Hyponatraemia, renal impairement, dementia
What are short term side effects of lithium?
GI upset, fine tremor, muscle weakness, polyuria and polydipsia
What are long term effects of lithium?
Oedema, weight gain, diabetes insipidus, renal damage, tardive dyskinesia, teratogenicity
What ECG changes are seen with long term lithium use?
T wave flattening
What is the teratogenic condition associated with lithium?
Ebsteins anomaly
At what levels does lithium toxicity occur?
> 1.5mmol/L
What are symptoms of lithium toxicity?
GI upset, CNS upset, psychosis, collapse, death
How is lithium toxicity treated?
Fluid resuscitation, haemodialysis, sodium bicarbonate
What does lithium interact with?
NSAIDs, ACEis, thiazides, carbemazepine
What is the therapeutic window of lithium?
0.4-1mmol/L
How often should lithium be monitored until a stable dose is reached?
Weekly
How often should lithium be monitored for the first year?
Every 3 months
How often should lithium be monitored after the first year?
Every 6 months
How do anti-convulsants work in bipolar?
Potentiate GABA transmission to stabilise mood