Background. Substantial variability in age at onset of
illness and course of illness exists between
patients with schizophrenia. Recent studies suggest that age at illness
onset may be useful in defining
biologically and clinically distinct subgroups of patients.
Methods. Two hundred and ten males with schizophrenia were
classified as early-onset or adult-onset according to their age at
first hospitalization. Birth history, clinical functioning and treatment
response was assessed in a subgroup of patients. Brain anatomy was assessed
from CT scans in all patients and in 32 non-psychiatric control subjects.
Results. Patients with an early-onset were likely to have a
history of obstetric complications, a poor
response to neuroleptic treatment, and showed no relationship between
ventricle size and duration
of illness. Adult-onset patients were less likely to have obstetric
complications, more likely to
respond to treatment in the first years of illness, and showed an
association between brain structure and duration of illness.
Conclusions. The distinction between early- and adult-onset
patients may have important aetiological and treatment implications.