In vivo evidence for early neurodevelopmental anomaly of the anterior cingulate cortex in bipolar disorder.

Objective: Anterior cingulate cortex (ACC) abnormalities are commonly reported in studies of patients with bipolar disorder (BD), but it is unclear whether these precede or follow illness onset. We investigated the evidence for early neurodevelopmental anomalies in the ACC and adjacent paracingulate cortex (PaC) of BD patients by studying cortical folding patterns of the region.

Method: Magnetic resonance images were acquired from 54 BD patients and 116 healthy controls. Cortical folding patterns were assessed by classifying the incidence of the paracingulate sulcus (PCS) and interruptions in the course of the cingulate sulcus (CS).

Results: Patients were significantly less likely to show a PCS bilaterally. There were no differences in the frequency of CS interruptions.

Conclusion: The bilateral reduction observed in our patient sample implicates aberrant pre- or peri-natal developmental processes. To our knowledge, this is the first in vivo evidence for early neurodevelopmental anomaly of the ACC/PaC region in BD.