CEREBRAL GRAY-MATTER VOLUME DEFICITS IN FIRST EPISODE PSYCHOSIS

Background: Structural brain differences including decreased gray matt er and increased cerebrospinal fluid volumes have been observed in the brains of chronically ill patients with schizophrenia. We hypothesize d that deficits in gray matter volume would be present in patients pre senting with a first episode of nonaffective psychosis. Methods: We us ed magnetic resonance imaging to compare the brains of 77 patients ass essed as having a first episode of psychosis (meeting DSM-III-R criter ia for schizophrenia, schizophreniform disorder, schizoaffective disor der, delusional disorder, or psychotic disorder not otherwise specifie d) with those of 61 healthy controls matched for age, sex, race, and p arental socioeconomic status. Axial, dual-echo scans of the whole brai n were segmented into gray matter, white matter, and cerebrospinal flu id compartments using a computerized volumetric approach. These measur es were corrected for the significant effects of intracranial volume a nd age prior to performing between-group comparisons. Results: The fir st episode psychosis group had significantly smaller gray matter volum e (t[136] = -2.2; P = .03) and greater cerebrospinal fluid volume (t[1 36] = 2.5; P = .02) than normal controls. In the patient group, gray m atter volumes were positively correlated with estimates of IQ but not with age of onset, duration of illness, or measures of premorbid funct ioning. Conclusions: Deficits in gray matter volume are present in pat ients experiencing first episode nonaffective psychosis. The magnitude of these differences is smaller than has been described in more chron ically ill patients.