In schizophrenia, brain morphometric changes may be associated with antipsychotic medication. Only limited data is available concerning individuals with schizophrenia without antipsychotic medication. We aimed to study the associations of: use versus no use of antipsychotic medication; length of continuous time without antipsychotic medication; cumulative dose of lifetime antipsychotic medication; and type of antipsychotic medication; with brain morphometry in schizophrenia after an average of 10 years of illness.

Data of 63 individuals with schizophrenia (mean duration of illness 10.4 years) from the Northern Finland Birth Cohort 1966 were gathered by interview and from hospital and outpatient records. Structural MRI data at age 34 years were acquired and grey matter volume maps with voxel-based morphometry were analyzed using FSL tools.

Of the individuals studied, 15 (24%) had taken no antipsychotic medication during the previous year. Individuals with antipsychotic medication had lower total grey matter (TGM) volume compared with non-medicated subjects, although this association was not statistically significant (Cohen's d=–0.51, P=0.078). Time without antipsychotic medication associated with increased TGM (P=0.028). Longer time without antipsychotic medication associated with increased regional volume in right precentral gyrus and right middle frontal gyrus. There were no associations between cumulative dose of lifetime antipsychotic medication or type of antipsychotic medication and brain morphometry.

Unlike some previous investigators, we found no association between cumulative dose of lifetime antipsychotic medication and brain morphological changes in this population-based sample. However, longer continuous time without antipsychotic medication preceding the MRI scan associated with increased gray matter volume.