7 Old age psychiatry7.5 Mental disorders in older people
7.5.6 Late life psychosis
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Written by Resident Doctor Committee · Published
Classification
Group | Age at onset |
|---|---|
Early-onset schizophrenia | Before 40 |
Late-onset schizophrenia | 40 to 60 |
Very-late-onset schizophrenia-like psychosis (VLOSLP) | After 60 |
Late paraphrenia is the older name for VLOSLP and is no longer a formal category.
The consensus terms are not ICD-11 diagnoses, so clinicians code the syndrome that meets criteria.
Epidemiology and risk factors
VLOSLP affects roughly 0.1 to 0.5% of older people living in the community.
Women predominate markedly, with reported female to male ratios of 4 to 9:1.
Family history of schizophrenia is weaker than in early-onset illness.
Over-represented factors are hearing loss and other sensory impairment, social isolation, premorbid paranoid traits, and migrant or ethnic minority status.
Psychosis first appearing in old age also reflects age-related change: cortical and neurochemical ageing, altered drug handling, cognitive decline and polypharmacy.
Clinical picture
Persecutory delusions occur in about 90% of late-onset schizophrenia, are organised, and often concern neighbours, intrusion, theft or poisoning.
Auditory hallucinations occur in about 75%, often as persistent third-person voices.
Affect is preserved and cognition is intact, with normal memory and orientation.
Partition delusions are beliefs that people or substances pass through a physical barrier, such as a wall or ceiling, into the home.
They are the signature delusion of VLOSLP, reported in roughly two thirds of very-late-onset cases against about a fifth of younger cases.
Compared with early-onset schizophrenia
Feature | Late-onset and VLOSLP | Early-onset schizophrenia |
|---|---|---|
Partition delusions | More frequent | Less frequent |
Passivity phenomena and catatonia | Less frequent | More frequent |
Negative symptoms and formal thought disorder | Few | More |
Premorbid functioning | Better | Poorer |
Neurodevelopmental markers | Absent | More common |
Antipsychotic dose needed | Low | Higher |
Tardive dyskinesia risk | Higher | Lower |
Differential diagnosis
New psychosis in later life is more often secondary to dementia than primary, particularly Alzheimer's disease.
In Alzheimer's disease, delusions of theft and of a phantom boarder arise from forgetting, alongside progressive amnestic decline.
Delirium needs urgent assessment in a physically unwell patient with new psychosis.
Other causes include Lewy body dementia, Huntington's disease, and dopaminergic, steroid and anticholinergic medicines.
Prominent voices separate VLOSLP from delusional disorder, and intact memory and orientation separate it from dementia and delirium.
Charles Bonnet syndrome (visual hallucinations with sight loss) and musical hallucinations with hearing loss are sensory release phenomena, favoured by retained insight and absent delusions.
Psychosis in Parkinson's disease
Hallucinations are mainly visual, and other modalities are much less common.
Passage hallucinations, fleeting impressions of something moving past in peripheral vision, appear early, before well-formed visual hallucinations.
Potent dopamine D2 antagonists are avoided because D2 blockade on top of nigrostriatal dopamine loss worsens motor features.
Deal with precipitants.
Reduce anticholinergics, amantadine, monoamine oxidase B (MAO-B) inhibitors and dopamine agonists first, and levodopa last, because it provokes psychosis least readily.
Start low-dose quetiapine, whose weak, short-lived D2 occupancy rarely worsens motor symptoms.
Offer clozapine if quetiapine fails; it has the best controlled-trial evidence, as weak, loosely bound D2 blockade with strong serotonin 5-HT2A antagonism leaves motor function intact.
Antipsychotic treatment
Antipsychotics raise mortality and cerebrovascular risk in older people with dementia, so in primary psychosis benefit and risk need individual weighing.
Start low, titrate cautiously, and monitor movement effects, falls, postural blood pressure and metabolic health.
Drug | Point for older adults |
|---|---|
Amisulpride | Trial evidence in VLOSLP; watch renal function, QT interval and parkinsonism |
Aripiprazole or low-dose risperidone | Alternatives suited to some patients |
Quetiapine | Strong alpha-1 adrenergic blockade gives a high risk of orthostatic hypotension, unlike amisulpride, aripiprazole and haloperidol |
Long-acting injectable, such as aripiprazole | Solves covert non-adherence causing relapse, using a drug already shown to work and be tolerated |
Clozapine | Age is no bar, but titrate more slowly because of postural hypotension, sedation and constipation |
Treatment-resistant schizophrenia, the indication for clozapine, means two adequate antipsychotic trials, including a second-generation drug, have failed with adherence confirmed.
For late-life depression after myocardial infarction, sertraline is the first-choice antidepressant, with the best cardiac safety evidence.
Selective serotonin reuptake inhibitors are well tolerated in later life, but check sodium early for hyponatraemia.
Psychological and social care
Optimise hearing aids and glasses, and reduce isolation through visiting, day activities or supported living.
Adapt cognitive behavioural therapy for psychosis to cognition, hearing and vision, focusing on distress and coping.
Course
The course may be chronic, and cognitive review continues because dementia may emerge later.
Poor insight alone does not establish incapacity.