Background: In consultation-liaison settings, neuropsychiatrists are commonly asked to assess patients with hallucinatory syndromes and to differentiate 'functional' from 'organic' psychotic presentations.
Methods: The occurrence and management of visual hallucinations (VH) in healthy individuals, lesion states, neurodegenerative disorders, intoxication/withdrawal states and delirium are reviewed.
Results: The presence of VH has been shown to predict a secondary rather than primary psychotic illness and an understanding of the neurobiology of the visual system - including how and where underlying neurotransmitter systems interact in visual processing and how perturbations can result in VH - allows for appropriate clinical assessment and management.