Psychotic disorders Flashcards
Definition of hallucinations, delusions, formal thought disorder
Hallucinations = perceptions without external stimulus
Delusions = fixed, false beliefs, held despite rational argument or evidence to the contrary. These can’t be explained by pt’s cultural, religious, or educational background.
Formal thought disorder = illogical/muddled thinking; people may experience this as struggling to think clearly
Psychotic disorder epidemiology
0.7% lifetime risk schizophrenia (3% any psychotic disorder)
late adolescence to early 20s usually
m:f 3:2 (men usually affected earlier and more severely)
Schizophrenia aetiology
Genetics = first-degree relatives, high heritability, multiple susceptibly genes
Obstetric complications = maternal prenatal malnutrition, viral infections, stress, analgesic use and obstetric hypoxia conditions (e.g. pre-eclampsia, C-section) and foetal growth retardation
Childhood adversity
Social disadvantage
Urbanicity = 2x more prevalent in urban
Migration and ethnicity= 1st + 2nd gen migrants higher risk, higher in black Caribbean and black African
Associated conditions = schizoid personality precedes schizophrenia 25% of time , schizotypal disorder more commonly associated with schizophrenia, possibly due to a shared genetic basis
Substance use disorders
- drug-induced psychosis = cannabis, amphetamines, cocaines and NPS
- can trigger relapse
- skunk (form of weed that has more THC) in teen increases risk of later developing schizophrenia
Neurotransmitter theory for psychotic disorders
positive sx’s (hallucination and delusion) = excess dopamine
negative sx’s (apathy, social withdrawal) = dopamine under activity
all known effective antipsychotics are dopamine antagonists (dopamine receptor blockers)
- work better for +ve than -ve sx’s
- dopaminergic agents (amphetamine, cocaine, L-dopa, bromocriptine can all induce psychotic sx’s)
- glutamate transmission effects dopamine transmission = PCP and ketamine cause schizophrenia-like psychosis by blocking glutamate transmission t NMDA receptors
Atypical antipsychotics are effective serotonin antagonists
3 stages of psychotic disorders
at-risk mental state (ARMS), acute phase, chronic phase
ARMS
20-30% with ARMS develop psychosis , half meet criteria for schizophrenia
period of very mild/brief psychotic sx’s, change in function (social withdrawal, loss of interest in activities, or mood sx)
e.g. late teens/early 20s dropped out of work or education after a period of increasing absence, may seem distant, isolating themselves in bedroom without giving reasons. May deny emerging psychotic sx for fear of their significance → psychosocial tx with CBT and family intervention recommended
hard to distinguish from depression, substance misuse, or ‘normal’ teenage behaviour
Acute phase
striking +ve symptoms
- delusions (usually persecutory)
- hallucinations (usually auditory)
formal thought disorder common = thoughts muddles speech disorganised, vagueness to disjointed speech that’s hard to follow and senseless
- thought blocking
behaviour = withdrawn, overactive, bizarre
may have a number of acute psychotic episodes over the years, with full or partial recovery between relapses
chronic phase
develop disabling -ve sx
- apathy
- blunted effect = decreased reactivity of mood
- anhedonia
- social withdrawal
- poverty of thought and speech
behaviour = self-neglect, social isolation, inactivity or withdrawal
may be residual and less prominent +e sx’s (e.g. persecutory delusions but seem less distressed and affected by them)
depression and antipsychotics side effects associated with -ve sx’s
often much easier to treat, don’t overlook them since tx can give someone a new lease of life
Schneider’s first rank symptoms
Auditory hallucinations
- running commentary on person’s actions
- third person voice
- thought echo
Thought withdrawal, insertion and interruption
Thought broadcasting
Somatic hallucinations
Delusional perception
Feelings or actions experiences as made or influenced by external agents
Organic causes
Dementia or delirium = especially in elderly patients
Medication side effects = steroids, dopamine agonists, levetiracetam (anticonvulsant aka Keppra)
Cerebral pathology = stroke, SOL, encephalitis, epilepsy, MS, cerebral lupus, HIV, neurosyphilis
Systemic illness = Wilson’s disease, porphyria, Cushing syndrome, hypo/hyperthyroidism
Drug use = amphetamine, cocaine/crack cocaine, LSD, ecstasy, ketamine, GHB/GBL, PCP and many NPS
Alcohol
- alcoholic hallcuinosis
- delirium tremens
Non-organic causes (‘functional psychosis’)
Schizophrenia = sx present for at least a month, affect multiple areas of mental state. May be psychomotor disturbances such as catatonic sx’s. Shouldn’t be diagnosed in the presence of striking mood disturbance.
Acute and transient psychotic disorder = psychotic sx’s occur suddenly and relatively briefly. Peak within 2 weeks and resolve within a month (max duration 3 months). Sx’s fluctuate rapidly, and may be acutely disabling. Not diagnosed if hx of another psychotic illness e.g. schizophrenia
Schizoaffective disorder = schizophrenia picture with mood disorder (moderate/sever depressive or mania) developing simultaneously.
Delusional disorder = delusions lasting more than 3 months, without a clear mood disturbance and lacking other schizophrenia sx’s such as thought disorder, persistent hallucinations, or negative sx’s
Schizotypal disorder = enduring state lasting years (actually a personality disorder). Eccentricity is central to diagnosis. May experience low-level or fleeting delusions or hallucinations. Risk of developing schizophrenia increased.
Puerperal (postpartum) psychosis = psychosis triggered by childbirth; usually occurs within a few weeks of delivery
Other differentials
PD = consider when lifelong pattern of interpersonal difficulties
- Paranoid PD = prominent detachment and negative affectivity traits, suspiciousness and paranoia
- Schizoid PD = prominent detachment traits, lack of interest in others or social norms (can resemble ARMS or negative sx’s)
Other differentials
PD = consider when lifelong pattern of interpersonal difficulties
- Paranoid PD = prominent detachment and negative affectivity traits, suspiciousness and paranoia
- Schizoid PD = prominent detachment traits, lack of interest in others or social norms (can resemble ARMS or negative sx’s)
- Borderline personality pattern = brief psychotic or psychotic-like sx can occur at times of stress, e.g. hearing voices, paranoia
Subtypes of schizophrenia (remember the most common one and its features)
see picture
Investigations
Full physical examination, collateral history and RA
Full set abs, FBC, CRP, LFTs, TFTs (anaemia, infection, alcohol, thyroid)
U+Es (renal function, electrolyte disorders)
Urine drug screen (UDS) and MSU = can identify common illicit substances e.g. cannabis and amphetamine, but many drugs like NPS can’t yet be detected
Consider HIV/syphilis if indicated and with prior counselling
Head CT if organic pathology suspected (not routine)
Baseline ECG = ideal, before starting an antipsychotic
NB: a medication-free period of inpatient observation may clarify the diagnosis if someone develops psychosis while using drugs
Additional Ix if clinical presentation suggests organic pathology
CT/MRI brain = older patients, hx head injury, or focal neurological signs
EEG = if epilepsy or another organic cause is suspected, e.g. prominent confusion
Anti-NMDA and VGKC antibodies = if autoimmune encephalitis is suspected
LP = for suspected encephalitis
Schizophrenia: At least ONE of the following
see below
Schizophrenia: At least ONE of the following
see below
Schizophrenia: at least TWO of the following
see picture
