Objective:
To define the epidemiology, phenomenology, premorbid and risk factors in patients with the first manifestation of a schizophrenia-like illness after the age of 60 years, and compare them with patients with an onset before the age of 25 years.
Design/setting/subjects:
All contacts for a non-affective psychotic illness across all ages of onset were ascertained through a psychiatric case register; patients were rediagnosed according to operationalized criteria for psychotic illness, and those with a very early and very late onset compared.
Main outcomes measures:
Phenomenological, premorbid and aetiological parameters were compared in the two groups, using risk ratios and 95% confidence intervals.
Results:
Very late onset patients (n = 72) were, compared to their very early onset counterparts (n = 192), more likely to be female, have good premorbid functioning and development history, and to exhibit persecutory delusions and hallucinations; they were less likely to have negative schizophrenic symptoms, to have a positive family history of schizophrenia, or have suffered pregnancy or birth complications.
Conclusions:
The results highlight premorbid, aetiological and phenomenological differences between patients with the onset of a schizophrenia-like illness at the extremes of adult life, and suggest it is premature to consider the two groups to be merely different manifestations of the same illness.