Since the initial reports of ventricular enlargement in schizophrenics, attempts have been made to define a subgroup of patients with brain atrophy on computerized axial tomography (CAT) scans. The authors reviewed this literature for clinical, biochemical, and environmental correlates of lateral and third ventricular enlargement as well as cortical and cerebellar atrophy and brain density. It is concluded that CAT abnormalities are useful markers in delineating a group of schizophrenics characterized predominantly by neuropsychological impairment, poor premorbid adjustment, global monoamine disturbance, poor treatment response to neuroleptics, lack of positive symptoms, and predominance of negative symptoms. A proposal for further classification of these patients is given both in terms of the dopamine hypothesis and Kraepelin's dementia praecox.