Psychosis in the Elderly

Psychosis is a particularly distressing psychiatric illness for sufferers and their carers, and it can feel especially difficult for practitioners dealing with its uncertain course and instilling hope in sufferers. Although assessing and managing a patient with psychosis in primary care can be daunting, the majority of patients should also receive input from mental health services. Psychotic symptoms are found in a wide range of medical and psychiatric conditions. Patients with psychosis in later life can be divided into three groups: those with pre-existing schizophrenia, new diagnoses of schizophrenia (‘late-life schizophrenia’, also known as ‘late paraphrenia’) and other conditions producing hallucinations or delusions (dementia, delirium, mood disorders, delusional disorder, paranoid personality disorders). As the population ages and treatments improve, the first group is getting significantly larger and making up a greater proportion of mental illness in older people. The prevalence of all psychotic disorders over 65 years of age is 4–6 %, rising to 10 % over 85 years. However, a large proportion of these cases are related to dementia. True schizophrenia or delusional disorder in the over 65 has a prevalence of 0.5–1.0 %. There is a female preponderance, with a ratio of female to males of 5:1, which is partly because the onset of schizophrenia tends to be later in females. Sixty per cent of older people with psychosis have paranoid schizophrenia, 30 % delusional disorder and only 10 % all other forms of psychosis.