MRI study of the pituitary gland in adolescent depression.

Abnormalities in pituitary function have been described in major depressive disorder (MDD) and may reflect neurodevelopmental abnormalities. We hypothesized alterations in the pituitary in early onset MDD. We measured the volume of the pituitary gland in 17 MDD (mean+/-S.D.=16.67+/-1.83 years; 8M, 9F) patients and 17 age and sex matched healthy controls (mean+/-S.D.=16.23+/-1.61 years; 8M, 9F) using 1.45 mm thick T(1)-weighted coronal MRI images. A trained rater blind to diagnosis did all measurements. ANCOVA covarying for age, sex and intracranial volume (ICV) revealed a significant difference between the two groups (F=6.43, df=1, 29, P=0.02; MDD subjects demonstrated a 25% increase in pituitary gland volume). Age was significantly correlated with pituitary volume in the healthy controls (r=0.62, P=0.008) but not the MDD group. No significant relationships between pituitary size and clinical severity were found in the MDD patients. To our knowledge, this is the first study that reports larger pituitary volumes in early onset major depression. These findings provide new evidence of abnormalities of the pituitary in early onset MDD, possibly related to neuroendocrine dysfunction.