• antipsychotic drugs
• first episode psychosis
• gender
• hippocampus
• MRI
• psychosis

Introduction: brain abnormalities have been found in patients at their first episode of psychosis.
It remains unclear whether antipsychotic drugs induce brain changes at this stage and whether such effects are dependent on drug type. To address this question I studied, in a sample of first episode psychosis patients, the volume of the hippocampus. This is a highly neuroplastic structure and it has been reported as reduced in chronic schizophrenia.
Methods: I compared 76 patients at their first episode of a functional psychosis (mean age: 28.1 ± 8.4 years, 46% female; 36 schizophrenia, 27 affective psychosis and 13 other psychosis according to DSM-IV criteria) with 76 sex and age matched controls.
Hippocampal volumes were manually traced using 1.5 mm coronal, 1.5T high resolution MRI images.
Results: there was no difference in hippocampal volume between patients and controls. However, female patients had smaller hippocampal volume than female controls (total volume: F= 6.1, p=0.01; right-side: F=7.0, p=0.01; left-side: F=3.6, p=0.06).
I did not find any correlation between cumulative dose of antipsychotic received at the time of MRI and hippocampal volumes.
Female patients on treatment, but not those drug–free, had smaller hippocampal volumes than female controls (total volume: F= 4.5, p=0.01; right-side: F=4.3, p=0.02; left-side: F=3.5, p=0.04); type of antipsychotic taken did not influence the results.
Discussion: these data suggest that at the time of the first psychotic episode the hippocampal structure is significantly affected in women but not in men; this may be due to a specific effect of antipsychotics in female patients. Findings could be explained by differences in the metabolism of drugs across gender, which is reflected on brain structures. Indeed, the influence of hormonal systems (such as the hypothalamic-pituitary-adrenal axis), which has been shown to influence brain volumes, might play also a role.