Background: The majority of patients with schizophrenia and mood disorders have disruptions in sleep and circadian rhythm.
Melatonin, which is secreted by the human pineal gland, plays an important role in sleep and circadian rhythm. The aim of the
present study was to evaluate and compare pineal gland volumes in patients with schizophrenia and mood disorders.
Subjects and methods: We retrospectively evaluated the pineal gland volumes of 80 cases, including 16 cases of unipolar
depression, 17 cases of bipolar disorder, 17 cases of schizophrenia, and 30 controls. The total pineal gland volume of all cases was
measured via magnetic resonance images, and the total mean pineal volume of each group was compared.
Results: The mean pineal volumes of patients with schizophrenia, bipolar disorder, unipolar depression, and the controls were
83.55±10.11 mm³, 93.62±11.00 mm³, 95.19±11.61 mm³ and 99.73±12.03 mm³, respectively. The mean pineal gland volume of the
patients with schizophrenia was significantly smaller than those of the other groups.
Conclusions: Our data show that patients with schizophrenia have smaller pineal gland volumes, and this deviation in pineal
gland morphology is not seen in those with mood disorders. We hypothesize that volumetric changes in the pineal gland of patients
with schizophrenia may be involved in the pathophysiology of this illness
