Objective: This study assessed the quantitative electroenchephalographic (QEEG) absolute power and coherence differences between a group of patients with bipolar I mood disorder (BMD I) and a group of patients with schizophrenia. We also examined the correlation between QEEG measures and family history of BMD.
Method: Using the National Institutes of Mental Health (NIMH) Global Rating Scale, we rated 18 adult inpatients with a DSM-III-R diagnosis of BMD I for the severity of the current episode. We also collected data on the family history of the illness. This group was then matched for age, sex, and handedness with an equal number of inpatients with a DSM-III-R diagnosis of schizophrenia. QEEG absolute power and coherence was calculated for the alpha bandwidth (8.0 to 12.0 Hz), assessed at 18 pairs of electrodes in both hemispheres during resting, eyes-closed condition in all the patients.
Results: The patients with schizophrenia showed significantly higher coherence (P = 0.047) at 6 pairs of electrodes on the right side. The group with BMD showed significantly higher power (P = 0.042) at 2 pairs of electrodes on the right side. Correlational analysis showed that QEEG measures were significantly correlated (P = 0.01) with positive family history of BMD.
Conclusion: These findings suggest that the patients with BMD are more disorganized in the right anterior hemisphere and that there is a significant positive correlation between the QEEG measures and the presence of family history of BMD. Further studies in a larger sample are required to confirm these preliminary findings.