Normal pituitary volumes in chronic schizophrenia

Pituitary volumes were shown to be abnormally large in pre- or first-psychotic episode patients and abnormally reduced in established schizophrenia by magnetic resonance imaging (MRI) studies. We present here the results of the second ever published MRI study exploring pituitary size in a large population of patients with chronic schizophrenia recruited from the geographically defined catchment area of South Verona, Italy. No significant differences for pituitary volumes were reported between 65 subjects with chronic schizophrenia and 65 normal individuals (mean age ± S.D. = 42.31 ± 11.44 and 40.54 ± 11.12 years). In contrast to Pariante et al. (2004), normal pituitary size was found in our population of chronic schizophrenia. Discrepancies between these two studies may partially be accounted by sample age and gender. Considering increased pituitary volumes in pre- or first-psychotic episode patients, we put forward the hypothesis that pituitary size may normalize or reduce with the progression of the illness as a result of reduced numbers of acute episodes and consequent diminished hypothalamus-pituitary-adrenal axis activity. To better test this hypothesis, future large MRI studies should investigate pituitary volumes in chronic schizophrenia longitudinally, also collecting pituitary hormones and cortisol, and comparing the effects of typical and atypical antipsychotics on pituitary size in a randomized trial.