Psychopathology is the systematic study of abnormal subjective experience and behaviour and it aims to give precise description, categorisation and definition of abnormal subjective experiences.

I aim to demonstrate that the most appropriate approach to elucidating the biological origins of psychiatric disorders is firstly to identify elementary abnormal phenomena and then to relate these to their underlying neural mechanisms. I will exemplify this by drawing attention to studies of Delusional Misidentification Syndromes (DSM).

I will show that there are impairments in face recognition memory in individuals with DSM without impairments in the recognition of emotion and that there are abnormalities of right hemisphere function and of the autonomic recognition pathways that determine sense of familiarity.

Basic psychopathological phenomena are more likely to throw light on the basic neural mechanisms that are important in psychiatric disorders than studying disease level categories.

The author has not supplied his declaration of competing interest.