Altered Hippocampal Morphology in Unmedicated Patients with Major Depressive Illness
Carrie E Bearden,
Paul M Thompson,
Christina Avedissian,
Andrea D Klunder,
Mark Nicoletti,
Nicole Dierschke,
Paolo Brambilla,
Jair C Soares
Affiliations
Carrie E Bearden
Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA 90095, U.S.A.
Paul M Thompson
Laboratory of Neuro Imaging, Department of Neurology, University of California, Los Angeles, CA 90095, U.S.A.
Christina Avedissian
Laboratory of Neuro Imaging, Department of Neurology, University of California, Los Angeles, CA 90095, U.S.A.
Andrea D Klunder
Laboratory of Neuro Imaging, Department of Neurology, University of California, Los Angeles, CA 90095, U.S.A.
Mark Nicoletti
Department of Psychiatry, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7160, U.S.A.
Nicole Dierschke
Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, U.S.A.
Paolo Brambilla
Scientific Institute IRCCS, E. Medea, and Section of Psychiatry, Department of Pathology and Experimental and Clinical Medicine, University of Udine, Udine, Italy
Jair C Soares
Department of Psychiatry and Behavioral Sciences, University of Texas at Houston School of Medicine, 1300 Moursund Street, Houston, TX 77030, U.S.A.
Despite converging evidence that major depressive illness is associated with both memory impairment and hippocampal pathology, findings vary widely across studies and it is not known whether these changes are regionally specific. In the present study we acquired brain MRIs (magnetic resonance images) from 31 unmedicated patients with MDD (major depressive disorder; mean age 39.2±11.9 years; 77% female) and 31 demographically comparable controls. Three-dimensional parametric mesh models were created to examine localized alterations of hippocampal morphology. Although global volumes did not differ between groups, statistical mapping results revealed that in MDD patients, more severe depressive symptoms were associated with greater left hippocampal atrophy, particularly in CA1 (cornu ammonis 1) subfields and the subiculum. However, previous treatment with atypical antipsychotics was associated with a trend towards larger left hippocampal volume. Our findings suggest effects of illness severity on hippocampal size, as well as a possible effect of past history of atypical antipsychotic treatment, which may reflect prolonged neuroprotective effects. This possibility awaits confirmation in longitudinal studies.
