Abnormalities of the corpus callosum in first episode, treatment naive schizophrenia
- 1Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, PA 15213, USA
- 2Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
- 3Wayne State University School of Medicine, University Health Center, 4201 St Antoine Blvd, Detroit, MI 48201, USA
- 4Center for Cognitive Medicine, University of Illinois at Chicago, Chicago, IL, USA
- Correspondence to: Dr M S Keshavan, Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, PA 15213, USA;
- Received 30 May 2001
- Accepted 8 February 2002
- Revised 28 January 2002
Background: Structural alterations in the association cortices as well as in the corpus callosum (CC) have been described in schizophrenia, and have been considered to reflect developmental abnormalities. Areas of primary and association cortices have been topographically mapped in the CC.
Objective: To investigate whether, in schizophrenia, there are alterations in CC subdivisions that connect association, but not primary, cortices, and also to see if the normative, developmentally mediated increase in CC size with age is absent in this disorder.
Methods: The midsagittal magnetic resonance imaging scans of 31 first episode, neuroleptic naive, schizophrenic patients, 12 non-schizophrenic, psychotic patients, and 31 healthy controls were compared. The total area of CC as well as that of anterior, middle and posterior genu, body, isthmus, and anterior, middle, and posterior splenii were measured.
Results: Patients with schizophrenia as a group had a smaller CC, anterior genu, anterior body, isthmus, and anterior splenium than normal controls. Furthermore, the age related increase in CC size seen in normal subjects was absent in the patients.
Conclusions: The observed reductions in size in selected regions of CC suggest a reduction in axonal connections between the heteromodal association cortices, which typically involve small diameter fibres. Furthermore, the absence of an age related increase in CC size in patients with schizophrenia suggests a neurodevelopmental abnormality that may extend into adolescence and early adulthood.
- CC, corpus callosum
- DSM, Diagnostic and statistical manual
- SCID, Structured clinical interview for DSM diagnosis
- MRI, magnetic resonance imaging