Psychosis in older adults: causes, assessment and treatment in the UK

The NHS describes the three main symptoms of psychosis as hallucinations (hearing, seeing and sometimes feeling, smelling or tasting things that do not exist outside the mind), delusions (strong beliefs not shared by others, such as a conspiracy to harm them) and disordered thinking and speech. Combined, these can cause severe distress and a change in behaviour.

In older adults these experiences may be part of a long-standing illness such as schizophrenia or bipolar disorder, may first appear in later life as part of a mood disorder, or may be caused by something physical. The NHS says it is sometimes possible to identify the cause of psychosis as a specific mental health condition, and that it can also be triggered by a physical condition such as a brain tumour or dementia.

Typical late-life experiences include believing that someone is stealing from you or that a partner is unfaithful, seeing people or animals in the room, or hearing voices or music. These are real and frightening to the person, and arguing about the facts rarely helps.

Because older people are more likely to have physical illness and to take several medicines, a careful search for physical and treatable causes is a central part of assessment. The NHS and Rethink Mental Illness list triggers including stress, drug misuse, alcohol, withdrawal from drugs or alcohol, side effects of prescribed medicine, a brain injury and a neurological condition such as dementia, Alzheimer's or Parkinson's. Rethink also lists menopause as a possible trigger.

• Delirium: the NHS lists infection, stroke or TIA, low blood sugar, head injury, some prescription medicines, alcohol withdrawal and lung or heart problems among causes of sudden confusion, and notes that urinary tract infections are a common cause in older people or those with dementia.

• Dementia: the NHS says dementia with Lewy bodies commonly causes visual hallucinations and hearing voices, with fluctuating confusion, slow movement and falls.

• Sight loss: Charles Bonnet syndrome causes visual hallucinations after significant sight loss, often linked to macular degeneration or cataracts, and most people know the hallucinations are not real.

• Medicines and substances: side effects of prescribed medicine and alcohol use are listed by the NHS among triggers of psychosis.

• Mental illness: schizophrenia, bipolar disorder and severe depression can all involve psychosis, including for the first time in later life.

The NHS says to go to A&E or call 999 if someone suddenly becomes confused, adding that many causes of sudden confusion need to be assessed and treated as soon as possible and sometimes may be life threatening. Do not drive them yourself; bring their medicines with you. It also advises asking for an urgent GP appointment or help from NHS 111 if you or someone else have hallucinations, to rule out more serious conditions.

For someone whose symptoms put them at risk, the NHS suggests taking them to the nearest A&E if they agree, calling their GP or out-of-hours GP, or calling 999 and asking for an ambulance. A gradual change, such as growing suspiciousness or forgetfulness over weeks, still needs a GP visit but is not usually an emergency.

The NHS says the GP may ask questions to determine what is causing psychosis and should refer to a mental health specialist for further assessment and treatment. For older adults, assessment typically includes a review of all medicines, a physical examination, blood and urine tests to look for infection or metabolic problems, checks of sight and hearing, an assessment of memory and thinking, and sometimes brain scanning.

Referral may be to an older people's community mental health team, a memory service or an old age psychiatrist. The NHS notes that if you are concerned about someone you know you can contact a GP for them, or their mental health worker if they receive support from a service.

Treatment depends on the cause. The NHS says treatment for psychosis usually involves a combination of antipsychotic medicine, talking therapies including CBT and family interventions, and social support. If the cause is physical, treating it, for example an infection or a medicine side effect, may resolve symptoms. For Charles Bonnet syndrome, the NHS says there is no cure but the hallucinations usually happen less often over time, and it suggests good lighting, rest, regular eye tests and talking therapy if they are upsetting.

In dementia, NICE says to offer antipsychotics only to people who are at risk of harming themselves or others, or experiencing agitation, hallucinations or delusions that are causing them severe distress. It says to discuss benefits and harms with the person and their family or carers, use the lowest effective dose for the shortest possible time, reassess at least every 6 weeks, and stop if there is no clear ongoing benefit. It also warns that in dementia with Lewy bodies or Parkinson's disease dementia antipsychotics can worsen movement symptoms and in some cases cause severe sensitivity reactions.

The NHS adds that people with severe mental illness are entitled to an annual physical health check at their GP surgery, and that medicines should not be stopped suddenly because this could trigger a relapse.

Stay calm, use simple words and short sentences, reassure and avoid arguing about what is real. The NHS advises that people with a history of psychosis are more likely to misuse alcohol or drugs, and that these can worsen symptoms. Keeping to a routine, good lighting, hearing aids and glasses worn, adequate fluids and sleep, and regular medicine reviews all help.

Carers need support too. Ask the GP about carers' assessments and local older adults' mental health services, and consider dementia or Parkinson's charities where relevant.

Most older adults with psychosis are assessed and treated through NHS older people's mental health teams, memory services and geriatric medicine, with GP involvement for physical health. Private old age psychiatrists can provide assessment and second opinions, but monitoring after antipsychotic prescribing, physical health checks and any social care package are normally coordinated with the NHS team and the GP.