Abstract
Cases are presented in which cerebral disease was associated with schizophrenic-like or manic-depressive-like psychoses, anxiety or obsessional states i.e. psychiatric disorders usually classed as ‘functional’. Evidence is presented to suggest that this association is not due to chance. The cerebral structural changes are characterized either by the presence of ‘focal’ lesions, e.g. multiple sclerosis, or by neuronal loss e.g. Huntington's chorea. The probable mechanisms whereby these two types of structural changes effect psychiatric disturbances are discussed. It is inferred that psychiatric disturbances will occur insofar as these cerebral structural changes exert an influence on the limbic systems.