The relationship between symptom severity and regional cortical and grey matter volumes in schizophrenia

To investigate the relationship between symptom severity and cortical and grey matter volumes in schizophrenia. Fifty-three outpatients with schizophrenia were assessed by the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms. Symptoms were grouped into five factors (negative, relational, inattention, disorganization, and reality distortion). Cortical and lobar grey matter volumes within all regions of the brain were obtained from magnetic resonance images using two independent software tools. The relationships between brain volumes and symptom factors were analyzed by partial correlations controlling for age, gender, dose and type of antipsychotic medication, and intracranial volume. Negative symptoms were generally associated with larger cortical volumes in all regions of the brain, and the relational and inattention factors were associated with larger frontal grey matter volumes. The reality distortion factor was associated with smaller cortical volumes throughout the brain and with smaller frontal and temporal grey matter volumes. Differential contribution of positive and negative symptoms to variation in cortical and grey matter volumes indicates separate neurobiological mechanisms underlying the two major symptom domains in schizophrenia.