Schizophrenia in later life

Schizophrenia is a severe mental illness. Most cases present in early adulthood, but 25 per cent begin in later life. Symptomatically, early and late onset disorders are similar with the exception that schizophrenia in later life is rarely accompanied by negative symptoms. Response to treatment is good in older patients and atypical antipsychotic drugs are the treatment of choice. The main barrier to improvement is non-compliance explains David Anderson.

Schizophrenia can occur at any time of life from childhood to old age. While it most commonly develops in adolescents and young adults - 75 per cent of cases have onset before 40 years of age - there are smaller peaks of incidence in middle age (around 40 years) and late life (after 60 years). However, regardless of age at onset, schizophrenia is considered to be a heterogeneous disorder, so that the term defines a group of related illnesses; the causes of which are unknown. As the disorder is defined by the symptom complex, and the symptoms are similar at all ages, there is no longer a separate category for onset in later life (previously called late paraphrenia) in the International Classification of Diseases (ICD-10). However, there are some differences in symptoms and associated factors between early- and late-onset disorder that prompt some authorities to argue that the distinction still has value.

Paranoid ideas have a point prevalence among elderly people in the community of about 4-6 per cent, with dementia being responsible for the majority of cases, and schizophrenia and related disorders being responsible for approximately 20 per cent. The prevalence of schizophrenia declines with age to about 0.1-0.5 per cent of people aged over 65 years.

Since the earliest reports, studies have found late onset schizophrenia to be associated with female gender - the condition is four times more common in females1 -deafness, and social isolation. Female gender and deafness are not associations of young-onset disorder though it is recognized that the average age of onset is higher for females. There is also a tendency for late-onset sufferers to have schizoid and paranoid premorbid personality traits although these may not amount to a diagnosis of personality disorder. Older patients have better premorbid function than the young and no association with obstetric complications at birth as found with young-onset schizophrenia patients2.

Late-onset disorder is associated with little genetic susceptibility in contrast to the findings with younger sufferers1.

Diagnosis is a clinical process requiring the presence of key symptoms evident from history taking and mental state examination. These are commonly referred to as positive and negative symptoms. The major difference in symptom profile between early- and late-onset schizophrenia is the relative lack of negative symptoms in late onset disorder which are frequently common in younger patients. The most common symptoms in older patients are persecutory delusions and auditory hallucinations.

Whenever possible, a corroborative history is needed from a third party to capture the full range of symptoms and behaviour present, and to identify risk. Patients are frequently suspicious and may conceal symptoms. The interview has to be non-confrontational, empathic, and should aim to create an atmosphere of trust. Psychotic symptoms should not be challenged or disregarded as imaginary or foolish or the patient's trust and cooperation could be lost. Eighty per cent of patients with schizophrenia have no insight into their condition and compliance with treatment can be difficult to achieve without the involvement of carers.

Some basic investigations are necessary with all patients to exclude physical causes. These should include:

  • A full blood count
  • ESR
  • Serum biochemistry
  • Thyroid function.

    Other investigations would be indicated from the history and examination. Physical examination should pay particular attention to neurological signs and sensory impairment.

    Some authorities recommend routine neuroimaging3as an aid to diagnosis. Like younger patients, structural brain-imaging studies of patients with late-onset schizophrenia typically find enlarged lateral and third ventricles and volume reduction of the left temporal lobe, while functional imaging indicates regions of hypoperfusion in both the frontal and temporal areas. At present, these are of academic interest as these abnormalities have not been shown to correlate with clinical symptoms or predict response to treatment and prognosis.

    Schizophrenia at any age is associated with a degree of cognitive impairment, particularly involving executive functions, learning, motor skills, and verbal ability. This impairment is not of a degree found with dementia and there is no evidence that late-onset schizophrenia is associated with the development of dementia. Psychometric testing is not a part of routine assessment.

    A number of conditions need to be considered when making a differential diagnosis (Table 2). Examination of the patient should look for the defining symptoms of these disorders, such as progressive cognitive impairment in dementia, acute and fluctuating cognitive impairment in delirium, and mood-related symptoms of affective disorders.

    Paranoid personality types are not psychotic and their distorted ideas are not delusions but over-valued ideas. They have a lifelong attitude that the world is against them. Sensory impairment alone can produce misunderstandings and distorted perceptions.

    Finally, it is essential to ensure that a patient's experiences are abnormal before we call them mentally ill. Sadly, older people are vulnerable and there are times when they express persecutory ideas because they are, in fact, being persecuted. It may need a good deal of enquiry and detective work to establish the facts.

    Most cases can be managed without hospital admission if the patient will accept that treatment and social support is at hand. Management requires a holistic approach, with particular attention being paid to the presence of physical illness, sensory impairment, and social isolation. These should be addressed wherever possible, though this alone very rarely alters symptoms significantly. The exception would be an organic schizophrenia-like disorder due to a treatable physical illness. This can be clinically indistinguishable from schizophrenia.

    The mainstay of treatment is antipsychotic medication to control positive symptoms. The dose for late-onset patients will be 25-50 per cent or less that given to younger patients. The rule is always to start with small doses and increase gently as necessary by titrating against response. The greater the age, physiological frailty, and the presence of poor physical health, the more cautious the dose titration needs to be.

    Advances in psychotropic drugs have produced medications with a lower incidence of adverse effects and a safer side-effect profile. The elderly benefit the most from these developments. Increasing age is a risk factor for most side effects and even minor adverse effects can have serious consequences in the elderly. Traditional, or typical, antipsychotics (e.g. haloperidol, chlorpromazine, and trifluperazine) have the potential to produce a range of troublesome and serious side effects, most notably involuntary movement disorders like Parkinsonism and the irreversible tardive diskinesia where age is the major risk factor.

    Because atypical antipsychotics (e.g. olanzapine, quetiapine, and low dose risperidone) do not cause involuntary movement disorders they should be the first choice drug treatment for older patients. This view is supported by the NICE guidelines published this month. They have the added benefit that they may have mood elevating effects and improve negative symptoms. Clozapine, the definitive atypical, is only licensed for treatment resistant schizophrenia and there is limited information about use with older patients. It is only available for prescription by psychiatrists and requires constant monitoring of blood count to detect drug-induced agranulocytosis that occurs in oneper cent of treated patients. When compliance is a problem, usually due to a lack of insight or an isolated patient with no carer, long-acting intramuscular depot antipsychotics (e.g. fluphenazine, or flupenthixol) are the preferred option. Unfortunately, the atypicals are not available in depot form.

    Of patients with late-onset schizophrenia, 50-60 per cent will show a full remission of psychotic symptoms in response to drug treatment and most of the remainder will show some useful improvement. Symptoms will usually return if medication is withdrawn and non-compliance is the most common reason for relapse and recurrence.

    The range of psychosocial approaches now employed with young schizophrenic patients and their families have yet to be investigated in late-onset disorder.

    Schizophrenia in late life resembles schizophrenia starting at younger ages though negative symptoms are rarely evident. The most common symptoms are persecutory delusions and auditory hallucinations. It is more common in females and has associations with deafness and social isolation. There is little genetic susceptibility. Neuroimaging and neurocognitive studies find abnormalities similar to those reported with young onset disorder. It is best treated with atypical antipsychotic drugs to avoid causing drug-induced involuntary movement disorders. However, non-compliance is the major barrier to treatment response.

    David Anderson is Consultant and Honorary Senior Lecturer in Old Age Psychiatry, Mossley Hill Hospital, Park Avenue, Liverpool

    References

    1. Castle D, Wessely S, Howard R, Murray R. Schizophrenia with onset at the extremes of adult life. Int J Geriat Psych 1997; 12: 712-17

    2. Howard R, Graham C, Sham P, Dennehy J, Castle D, Levy R, Murray R. A controlled family study of late-onset non-affective psychosis (late paraphrenia). Br J Psych 1997; 170: 511-14

    3. Howard R, Rabins P, Seeman M, Jeste D. Late-onset schizophrenia and very-late-onset schizophrenia-like psychosis: An international consensus. Am J Psych 2000; 157: 172-8

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