Risk factors in early and late onset schizophrenia.

BACKGROUND: This study looks at key risk factors in patients with schizophrenia to identify trends according to age of onset, comparing presentations prior to 26years (youth onset), between 26 and 40years (middle onset), and after 40years of age (late onset).

METHODS: The early psychosis program at St Vincent's Hospital Melbourne treats patients presenting in the early stages of psychosis between 16 and 65years of age. A database was developed to capture key risk factors in all patients with an eventual diagnosis of schizophrenia (n=225). Risk factor profiles were then generated and compared for patients based on age of onset.

RESULTS: Older age of onset was associated with weaker family history of schizophrenia, lower rates of substance use, better early psychosocial functioning and higher educational achievement. Female preponderance and comorbid physical health problems were particularly notable in the late onset cohort. Later life schizophrenia also showed a relatively greater association with psychosocial factors proximal to psychosis onset, such as unemployment.

DISCUSSION: Clear trends are noticeable with age. Older patients have characteristic differences in their background risk factors compared to youth onset patients, including less hereditary influence and relatively more emphasis on later life risk factors. Identifying the roles of specific risk factors in these distinct age-onset groups can enhance our understanding of underlying aetiology and facilitate service development to meet the needs of each specific age group.