The case for a psychological perspective on late-onset psychosis.

OBJECTIVE

A conceptual framework is proposed for studying late-onset psychotic disorders. This incorporates developmental and psychological perspectives to complement the biological focus of most recent studies in this area.

METHOD

Studies of late-onset psychosis that focus on the specificity of neuroimaging abnormalities, family history and sensory deficits were reviewed. Aspects of the developmental and personality literature were then examined with the goal of ascertaining their relevance for the emergence of psychosis in late life. Possible future directions incorporating biological and psychological approaches are proposed.

RESULTS

The biological abnormalities identified in studies of late-onset psychosis lack the specificity to stand alone as aetiological factors. Neuroimaging changes and sensory impairment are commonly found in study subjects; however, they also occur in elderly persons without psychiatric illness as well as in those with other late-onset psychiatric disorders. Perhaps it is more appropriate to regard these changes as conferring a vulnerability to psychosis in old age, but symptoms do not develop unless other risk factors, either longstanding or ageing-related, are also present. Developmental studies of late life that have used Erikson's concept of a final lifestage crisis of achieving 'ego-integrity', suggest that personality style may be influential in determining the negotiation of this last maturational task. Failure to do so results in 'despair', fragmentation of self-image and paranoid fears. To date, there has been little investigation of the relevance of these developmental and personality factors for the emergence of psychosis in old age.

CONCLUSIONS

If we are to advance our understanding of late-onset psychotic disorders, research in this area needs to move beyond the elusive search for specific biological markers. A model of causation that integrates the longitudinal perspective of lifestage tasks with personality and biological vulnerability factors provides a broad framework which protects against premature foreclosure on aetiological determinants.